Class ComboDropDown

Inheritance

System.Object

ComboDropDown

ComboBoxBase

Implements

IThemedControl

System.ComponentModel.ISupportInitialize

INonClientPaintingSupport

ISupportOffice2007Theme

IVisualStyle

Namespace: Syncfusion.Windows.Forms.Tools

Assembly: Syncfusion.Shared.Base.dll

Syntax

public class ComboDropDown : Control, IThemedControl, ISupportInitialize, INonClientPaintingSupport, ISupportOffice2007Theme, IVisualStyle

Constructors

ComboDropDown()

Creates a new instance of the ComboDropDown class.

Declaration

public ComboDropDown()

Fields

autoCompleteSuccess

Declaration

protected bool autoCompleteSuccess

Field Value

Type	Description
System.Boolean

cachedBackColor

Cached BackColor of ComboBox.

Declaration

protected Color cachedBackColor

Field Value

Type	Description
System.Drawing.Color

cachedForeColor

Cached BackColor of ComboBox.

Declaration

protected Color cachedForeColor

Field Value

Type	Description
System.Drawing.Color

initializing

Declaration

protected bool initializing

Field Value

Type	Description
System.Boolean

m_lastFoundIndex

Declaration

protected int m_lastFoundIndex

Field Value

Type	Description
System.Int32

m_scrollersFrame

Declaration

protected ScrollersFrame m_scrollersFrame

Field Value

Type	Description
ScrollersFrame

Properties

AllowMouseWheelSelection

Gets or sets a value indicating whether selection changing can be done using mouse wheel rotation.

Declaration

public bool AllowMouseWheelSelection { get; set; }

Property Value

Type	Description
System.Boolean	true if seelction can be changed using mouse wheel; otherwise, false.

Remarks

Instead of handling mouse wheel event and handling it, user can set this bool property as per the needs. This property is used to work when the dropdown is not shown and changing selection through mouse wheel.

AllowQuickSelection

Gets or sets a value indicating if quick selection on mouse move is on.

Declaration

public bool AllowQuickSelection { get; set; }

Property Value

Type	Description
System.Boolean

BackColor

Gets or sets the back color. (overridden property)

Declaration

public override Color BackColor { get; set; }

Property Value

Type	Description
System.Drawing.Color

BackgroundImage

Specifies the BackgroundImage.(overridden property)

Declaration

public override Image BackgroundImage { get; set; }

Property Value

Type	Description
System.Drawing.Image

BackgroundImageLayout

Gets or sets background image layout.

Declaration

public ImageLayout BackgroundImageLayout { get; set; }

Property Value

Type	Description
System.Windows.Forms.ImageLayout

BeforeTouchSize

Gets/Sets Control size before touch enabled

Declaration

public Size BeforeTouchSize { get; set; }

Property Value

Type	Description
System.Drawing.Size

Border3DStyle

Gets or sets the 3D border style for the control.

Declaration

public Border3DStyle Border3DStyle { get; set; }

Property Value

Type	Description
System.Windows.Forms.Border3DStyle

Remarks

This property is used only when BorderStyle is Fixed3D.

BorderSides

Gets or sets the border sides for which you want the 3D border style applied.

Declaration

public Border3DSide BorderSides { get; set; }

Property Value

Type	Description
System.Windows.Forms.Border3DSide

Remarks

This property is used only when BorderStyle is Fixed3D.

CaseSensitiveAutocomplete

Indicates whether the search in autocomplete is case-sensitive.

Declaration

public bool CaseSensitiveAutocomplete { get; set; }

Property Value

Type	Description
System.Boolean

CharacterCasing

Specifies the ComboBoxBase control modifies the case of characters as they are typed.

Declaration

public virtual CharacterCasing CharacterCasing { get; set; }

Property Value

Type	Description
System.Windows.Forms.CharacterCasing	One of the System.Windows.Forms.CharacterCasing enumeration values that specifies whether the ComboBoxBase control modifies the case of characters. The default is CharacterCasing.Normal.

ComboBoxRenderer

Update the renderer for Office2016 style.

Declaration

protected virtual ComboBoxAdvRenderer ComboBoxRenderer { get; }

Property Value

Type	Description
ComboBoxAdvRenderer

ContextMenu

Gets or sets the ContextMenu. (overridden property)

Declaration

public override ContextMenu ContextMenu { get; set; }

Property Value

Type	Description
System.Windows.Forms.ContextMenu

CreateParams

Declaration

protected override CreateParams CreateParams { get; }

Property Value

Type	Description
System.Windows.Forms.CreateParams

DefaultSize

Declaration

protected override Size DefaultSize { get; }

Property Value

Type	Description
System.Drawing.Size

DropDownButton

Returns the DropDownButton used to draw the drop-down portion of the combo.

Declaration

public DropDownButton DropDownButton { get; }

Property Value

Type	Description
DropDownButton

DropDownButtonHeight

Gets or sets the height of the drop-down button.

Declaration

protected int DropDownButtonHeight { get; set; }

Property Value

Type	Description
System.Int32

DropDownStyle

Gets or sets the style of the combo box.

Declaration

public ComboBoxStyle DropDownStyle { get; set; }

Property Value

Type	Description
System.Windows.Forms.ComboBoxStyle	One of the System.Windows.Forms.ComboBoxStyle values. The default is System.Windows.Forms.ComboBoxStyle.DropDown.

Remarks

The DropDownStyle property controls the interface that is presented to the user. You can enter a value that allows for a simple drop-down list box, where the list always displays a drop-down list box, where the text portion is not editable and you must select an arrow to view the drop-down, or the default drop-down list box where the text portion is editable and the user must press the arrow key to view the list.

DropDownWidth

Gets or sets the drop-down's width.

Declaration

public int DropDownWidth { get; set; }

Property Value

Type	Description
System.Int32

Remarks

The value provided here will be used to determine the width of the drop-down portion. If you do not set a value explicitly, the width of this control will be used as the preferred width.

To reset your settings on this property, call the ResetDropDownWidth() method.

DroppedDown

Indicates whether the combo box is displaying its drop-down portion.

Declaration

public bool DroppedDown { get; set; }

Property Value

Type	Description
System.Boolean	True if the drop-down portion is displayed; False otherwise. The default is False.

EditPortionHeight

Gets or sets the height of the edit portion.

Declaration

protected int EditPortionHeight { get; set; }

Property Value

Type	Description
System.Int32

EnableTouchMode

Gets or sets value to enable or disable the Touchmode to the controls.

Declaration

public bool EnableTouchMode { get; set; }

Property Value

Type	Description
System.Boolean

Remarks

Scale factor will be updated automatically if scalefactor is equal to 1

FlatBorderColor

Gets or sets the color with which the flat border should be drawn.

Declaration

public virtual Color FlatBorderColor { get; set; }

Property Value

Type	Description
System.Drawing.Color	A color value. Default is SystemColors.ControlDark.

Remarks

This is also the color used to draw the border when the Style property is set to OfficeXP or Office2003.

FlatStyle

Gets or sets the flat style appearance of the combo box control.

Declaration

public virtual ComboFlatStyle FlatStyle { get; set; }

Property Value

Type	Description
ComboFlatStyle	One of the ComboFlatStyle values. The default value is Standard.

Remarks

When you specify System and the application is run in Windows XP, themes will be used to draw this control.

Use IsThemedOS and IsThemeActive to determine if themes are on during run-time.

Focused

Specifies whether the control is focused. (overridden property)

Declaration

public override bool Focused { get; }

Property Value

Type	Description
System.Boolean

Font

Gets or sets the System.Drawing.Font value for the control.

Declaration

public override Font Font { get; set; }

Property Value

Type	Description
System.Drawing.Font

ForeColor

Gets or sets the ForeColor. (overridden property)

Declaration

public override Color ForeColor { get; set; }

Property Value

Type	Description
System.Drawing.Color

GrayOnReadOnly

Gets or sets a value indicating to show the Gray BackColor on ReadOnly is set.

Declaration

public bool GrayOnReadOnly { get; set; }

Property Value

Type	Description
System.Boolean

IgnorePopupValueChange

Declaration

protected bool IgnorePopupValueChange { get; set; }

Property Value

Type	Description
System.Boolean

IgnoreThemeBackground

Indicates whether the control will ignore the theme`s background color and draw the BackColor instead.

Declaration

public virtual bool IgnoreThemeBackground { get; set; }

Property Value

Type	Description
System.Boolean

IsInitializing

Gets a value indicating whether this instance is initializing.

Declaration

public bool IsInitializing { get; }

Property Value

Type	Description
System.Boolean

IsPopUpControlType

Check whether the ComboBox is ComboDropDown or ComboBoxAdv

Declaration

public bool IsPopUpControlType { get; }

Property Value

Type	Description
System.Boolean

LastCommittedText

Declaration

protected string LastCommittedText { get; set; }

Property Value

Type	Description
System.String

MatchFirstCharacterOnly

This property defines the autocomplete behavior in DropDownList mode.

Declaration

public bool MatchFirstCharacterOnly { get; set; }

Property Value

Type	Description
System.Boolean

Remarks

This property is used when the DropDownStyle is set to DropDownList only.

MaxLength

Gets or sets the maximum number of characters allowed in the editable portion of a combo box.

Declaration

public int MaxLength { get; set; }

Property Value

Type	Description
System.Int32	The maximum number of characters the user can enter. Default value is 32767.

MetroBorderColor

Gets or sets the BorderColor for metro style

Declaration

public Color MetroBorderColor { get; set; }

Property Value

Type	Description
System.Drawing.Color

MetroColor

Gets or sets the metrocolor.

Declaration

public Color MetroColor { get; set; }

Property Value

Type	Description
System.Drawing.Color

NeedLayout

Indicates whether the layout method needs to be called to layout the combo elements.

Declaration

public bool NeedLayout { get; }

Property Value

Type	Description
System.Boolean

Remarks

Internal method. You will not have to call this property explicitly.

NumberOnly

Indicates whether users should be forced to enter numbers.

Declaration

public virtual bool NumberOnly { get; set; }

Property Value

Type	Description
System.Boolean	True to force numbers; False otherwise.

Office2007ColorTheme

Gets or sets office 2007 color theme.

Declaration

public Office2007Theme Office2007ColorTheme { get; set; }

Property Value

Type	Description
Office2007Theme

Office2010ColorTheme

Gets or sets office 2010 color theme.

Declaration

public Office2010Theme Office2010ColorTheme { get; set; }

Property Value

Type	Description
Office2010Theme

PopupContainer

Returns the PopupControlContainer used to host the drop-down list.

Declaration

public PopupControlContainer PopupContainer { get; }

Property Value

Type	Description
PopupControlContainer

PopupControl

The System.Windows.Forms.Control that will be used in the drop-down portion.

Declaration

public virtual Control PopupControl { get; set; }

Property Value

Type	Description
System.Windows.Forms.Control	A System.Windows.Forms.Control derived instance.

PreventHeightChange

Indicates whether the Height property of the control can be changed.

Declaration

protected bool PreventHeightChange { get; set; }

Property Value

Type	Description
System.Boolean	True to prevent height change; False otherwise .

Remarks

Note that this property will be frequently set and reset within the control layout. You can use this temporarily to force a particular height on the control.

ReadOnly

Indicates whether the text in the edit portion can be changed.

Declaration

public virtual bool ReadOnly { get; set; }

Property Value

Type	Description
System.Boolean	If True, the edit portion is not editable by the user; False otherwise.

RightToLeft

Gets or sets a value indicating whether control's elements are aligned to support locales using right-to-left fonts.

Declaration

public override RightToLeft RightToLeft { get; set; }

Property Value

Type	Description
System.Windows.Forms.RightToLeft

Style

Gets or sets an advanced appearance and behavior for this control.

Declaration

public VisualStyle Style { get; set; }

Property Value

Type	Description
VisualStyle	One of the VisualStyle values. Default is VisualStyle.Default.

Remarks

When a non-default style is specified here, it will override the other settings of the control such as BorderSides and FlatStyle. The FlatBorderColor is used to draw the borders for the office styles, when the control is not active.

The Office2003 style behaves the same as OfficeXP in non-XP systems.

SuppressDropDownEvent

Indicates whether to suppress the DropDown Event

Declaration

public bool SuppressDropDownEvent { get; set; }

Property Value

Type	Description
System.Boolean

Text

Gets or sets the text associated with this control.

Declaration

public override string Text { get; set; }

Property Value

Type	Description
System.String

Remarks

When in DropDownList mode, setting this property will also validate the new value against the attached popup control.

TextAlign

Gets or sets the alignment of text in this control.

Declaration

public virtual HorizontalAlignment TextAlign { get; set; }

Property Value

Type	Description
System.Windows.Forms.HorizontalAlignment	One of the System.Windows.Forms.HorizontalAlignment enumeration values that specifies how text is aligned in the control. The default is HorizontalAlignment.Left.

Remarks

You can use this property to align the text within a ComboBoxBase to match the layout of text on your form. For example, if your controls are all located on the right side of the form, you can set the TextAlign property to HorizontalAlignment.Right and the text will be aligned along the right side of the control instead of the default left alignment.

TextBox

Returns the System.Windows.Forms.TextBox used to draw the editable text portion of the combo.

Declaration

public TextBox TextBox { get; }

Property Value

Type	Description
System.Windows.Forms.TextBox

UseBackColor

Gets or sets a value to have effect of BackColor

Declaration

public bool UseBackColor { get; set; }

Property Value

Type	Description
System.Boolean

UseMetroButtonColor

Declaration

public bool UseMetroButtonColor { get; set; }

Property Value

Type	Description
System.Boolean

UseMetroColorsInActiveMode

Gets or sets a value indicating whether [use metro colors in active mode].

Declaration

public bool UseMetroColorsInActiveMode { get; set; }

Property Value

Type	Description
System.Boolean	true if [use metro colors in active mode]; otherwise, false.

UseMnemonic

Declaration

public bool UseMnemonic { get; set; }

Property Value

Type	Description
System.Boolean

UseOffice2007ColorsInActiveMode

Gets or sets a value indicating whether [use office2007 colors in active mode].

Declaration

public bool UseOffice2007ColorsInActiveMode { get; set; }

Property Value

Type	Description
System.Boolean	true if [use office2007 colors in active mode]; otherwise, false.

Methods

ApplyScaleToControl(Single)

Scale the control based on the scale factor passed in the argument.

Declaration

public void ApplyScaleToControl(float scaleFactor)

Parameters

Type	Name	Description
System.Single	scaleFactor	value to scale the factor based upon.

AttachPopupControl()

Declaration

protected virtual void AttachPopupControl()

AttachScrollersFrame(Control)

Attaches scrollersFrame to the PopupControl.

Declaration

protected void AttachScrollersFrame(Control control)

Parameters

Type	Name	Description
System.Windows.Forms.Control	control

CommitChanges()

Declaration

protected virtual void CommitChanges()

CreateAccessibilityInstance()

Declaration

protected override AccessibleObject CreateAccessibilityInstance()

Returns

Type	Description
System.Windows.Forms.AccessibleObject

CreateDropDownButton()

Called once to create a DropDownButton for the drop-down button portion of the combo.

Declaration

protected virtual DropDownButton CreateDropDownButton()

Returns

Type	Description
DropDownButton	A new instance of a DropDownButton.

Remarks

Override this method to provide a custom implementation of a DropDownButton. InitDropDownButton(DropDownButton)

CreatePopupContainer()

Called once to create a PopupControlContainer that will host the drop-down list.

Declaration

protected virtual PopupControlContainer CreatePopupContainer()

Returns

Type	Description
PopupControlContainer	A new instance of a PopupControlContainer.

Remarks

Override this method to provide a custom implementation of the PopupControlContainer. InitPopupContainer()

CreateScrollersFrame()

Creates new instance of the scrollersFrame.

Declaration

protected ScrollersFrame CreateScrollersFrame()

Returns

Type	Description
ScrollersFrame

CreateTextBox()

Called once to create a System.Windows.Forms.TextBox for the editable text portion of the combo.

Declaration

protected virtual TextBox CreateTextBox()

Returns

Type	Description
System.Windows.Forms.TextBox	A new instance of a System.Windows.Forms.TextBox.

Remarks

Override this method to provide a custom implementation of a text box. InitTextBox()

DefWndProc(ref Message)

Sends the specified message to the default windows procedure.

Declaration

protected override void DefWndProc(ref Message msg)

Parameters

Type	Name	Description
System.Windows.Forms.Message	msg

DetachPopupControl(Boolean)

Declaration

protected virtual void DetachPopupControl(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing

DetachScrollersFrame()

Detaches scrollersFrame from the PopupControl.

Declaration

protected void DetachScrollersFrame()

DetermineHeightsBasedOnFont(Graphics, ref Int32)

Determines the heights of certain portions of this control.

Declaration

protected virtual void DetermineHeightsBasedOnFont(Graphics g, ref int textAreaHeight)

Parameters

Type	Name	Description
System.Drawing.Graphics	g	A System.Drawing.Graphics object.
System.Int32	textAreaHeight	A reference variable through which to return the height for the text area.

Remarks

Make sure to call the base class when you override this method.

This method expects you to return a height for the text area through the reference variable, set the height of this control (if not in ComboBoxStyle.Simple mode) and the height of the drop-down button (DropDownButtonHeight).

Dispose(Boolean)

Declaration

protected override void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing

DrawBorderAndBackground(Graphics, Rectangle)

Draws the border and background of the control.

Declaration

protected virtual void DrawBorderAndBackground(Graphics g, Rectangle rect)

Parameters

Type	Name	Description
System.Drawing.Graphics	g	The System.Drawing.Graphics context.
System.Drawing.Rectangle	rect	The System.Drawing.Rectangle within which to draw.

Remarks

This method is used to draw the border around the text area (when called from DrawEditPortionBorderAndBackground(PaintEventArgs) method) and around the list box area (when in ComboBoxStyle.Simple mode and called from the DrawListPortion(PaintEventArgs) method).

This method uses themes to draw if necessary or calls DrawUnThemedBackground(Graphics, Rectangle) and DrawUnThemedBorder(Graphics, Rectangle) to draw the background and border.

DrawDropDownPortion(PaintEventArgs)

Called from the Paint event handler to draw the drop-down button.

Declaration

protected virtual void DrawDropDownPortion(PaintEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.PaintEventArgs	e	The System.Windows.Forms.PaintEventArgs from the Paint event.

DrawEditPortion(PaintEventArgs)

Called from the Paint event handler to draw the text portion.

Declaration

protected virtual void DrawEditPortion(PaintEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.PaintEventArgs	e	The System.Windows.Forms.PaintEventArgs from the Paint event.

Remarks

This method calls the DrawListModeEditPortion(PaintEventArgs, Color, Color, Boolean) method to draw the edit portion only when in ComboBoxStyle.DropDownList mode or when in design-mode.

DrawEditPortionBorderAndBackground(PaintEventArgs)

Called from the Paint event handler to draw the edit portion's border and background.

Declaration

protected virtual void DrawEditPortionBorderAndBackground(PaintEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.PaintEventArgs	e	The System.Windows.Forms.PaintEventArgs from the Paint event.

Remarks

This method calls the DrawBorderAndBackground(Graphics, Rectangle) method with the appropriate dimension to draw the border around the text portion.

DrawListModeEditPortion(PaintEventArgs, Color, Color, Boolean)

Called from DrawEditPortion(PaintEventArgs) to draw the text area when in ComboBoxStyle.DropDownList mode.

Declaration

protected virtual void DrawListModeEditPortion(PaintEventArgs e, Color highlightBG, Color highlightText, bool drawFocusRect)

Parameters

Type	Name	Description
System.Windows.Forms.PaintEventArgs	e	The System.Windows.Forms.PaintEventArgs from the Paint event.
System.Drawing.Color	highlightBG	The background color for the highlight.
System.Drawing.Color	highlightText	The text color for the highlight.
System.Boolean	drawFocusRect	Indicates whether to draw a focus rectangle.

DrawListPortion(PaintEventArgs)

Called from the Paint event handler to draw the list portion.

Declaration

protected virtual void DrawListPortion(PaintEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.PaintEventArgs	e	The System.Windows.Forms.PaintEventArgs from the Paint event.

Remarks

This method draws the list portion when in ComboBoxStyle.Simple mode.

DrawUnThemedBackground(Graphics, Rectangle)

Draws the unthemed background of this control.

Declaration

protected virtual void DrawUnThemedBackground(Graphics g, Rectangle rect)

Parameters

Type	Name	Description
System.Drawing.Graphics	g	The System.Drawing.Graphics context.
System.Drawing.Rectangle	rect	The System.Drawing.Rectangle within which to draw.

Remarks

Called by DrawBorderAndBackground(Graphics, Rectangle) to draw the background when not in themes mode.

DrawUnThemedBorder(Graphics, Rectangle)

Draws the unthemed border of this control.

Declaration

protected virtual void DrawUnThemedBorder(Graphics g, Rectangle rect)

Parameters

Type	Name	Description
System.Drawing.Graphics	g	The System.Drawing.Graphics context.
System.Drawing.Rectangle	rect	The System.Drawing.Rectangle within which to draw.

Remarks

Called by DrawBorderAndBackground(Graphics, Rectangle) to draw the border when not in themes mode.

FindItem(String, Boolean, Int32, Boolean)

Declaration

protected virtual int FindItem(string prefix, bool select, int start, bool ignoreCase)

Parameters

Type	Name	Description
System.String	prefix
System.Boolean	select
System.Int32	start
System.Boolean	ignoreCase

Returns

Type	Description
System.Int32

ForwardKeyMessageToPopupControl(Int32, IntPtr, IntPtr)

Forwards the key message to the attached PopupControl.

Declaration

protected virtual void ForwardKeyMessageToPopupControl(int msg, IntPtr wparam, IntPtr lparam)

Parameters

Type	Name	Description
System.Int32	msg	The message id.
System.IntPtr	wparam	The first message parameter.
System.IntPtr	lparam	The second message parameter.

GetComboBoxDropDownWidth()

Returns the width for the combo box drop-down button.

Declaration

protected virtual int GetComboBoxDropDownWidth()

Returns

Type	Description
System.Int32	The button width.

GetEmbeddedChildBounds()

The bounds for the control that is associated with this popup when in DropDownStyle.Simple mode.

Declaration

protected virtual Rectangle GetEmbeddedChildBounds()

Returns

Type	Description
System.Drawing.Rectangle	The bounds for the embedded control.

GetEmbeddedChildBounds(Int32)

Overloaded. The bounds for the control that is associated with this popup when in DropDownStyle.Simple mode.

Declaration

protected virtual Rectangle GetEmbeddedChildBounds(int comboHeight)

Parameters

Type	Name	Description
System.Int32	comboHeight	The height of the combo control.

Returns

Type	Description
System.Drawing.Rectangle	The bounds for the embedded control.

GetOfficeStyleComboBoxDropDownWidth()

Returns the width for the combo box drop-down button when office style is on.

Declaration

protected virtual int GetOfficeStyleComboBoxDropDownWidth()

Returns

Type	Description
System.Int32	The button width.

GetPopupControlItemText(Int32)

Declaration

protected virtual string GetPopupControlItemText(int index)

Parameters

Type	Name	Description
System.Int32	index

Returns

Type	Description
System.String

GetPopupText()

Declaration

protected virtual string GetPopupText()

Returns

Type	Description
System.String

HasListInterface()

Declaration

protected virtual bool HasListInterface()

Returns

Type	Description
System.Boolean

HidePopup()

Hides the drop-down list box.

Declaration

protected virtual void HidePopup()

InitDropDownButton(DropDownButton)

Called to initialize the DropDownButton used in the drop-down button portion of the combo.

Declaration

protected virtual void InitDropDownButton(DropDownButton ddButton)

Parameters

Type	Name	Description
DropDownButton	ddButton

Remarks

This method is called once to initialize the DropDownButton used to draw the drop-down portion of the combo.

Make sure to call the base class when you override this method for default initialization.

CreateDropDownButton()

InitPopupContainer()

Called to initialize the drop-down container.

Declaration

protected virtual void InitPopupContainer()

Remarks

This method is called once to initialize the drop-down container that hosts the drop-down list. Use the PopupContainer property to get a reference to the PopupControlContainer from inside an override of this method.

Make sure to call the base class when you override this method for default initialization.

CreatePopupContainer()

InitScrollersFrame()

Inits the scrollers frame.

Declaration

protected virtual void InitScrollersFrame()

InitTextBox()

Called to initialize the System.Windows.Forms.TextBox used in the editable text portion.

Declaration

protected virtual void InitTextBox()

Remarks

This method is called once to initialize the text box used to draw the editable portion of the combo. Use the TextBox property to get a reference to the text box from inside a override of this method.

Make sure to call the base class when you override this method for default initialization.

CreateTextBox()

IsInputChar(Char)

Declaration

protected override bool IsInputChar(char charCode)

Parameters

Type	Name	Description
System.Char	charCode

Returns

Type	Description
System.Boolean

IsInputKey(Keys)

Declaration

protected override bool IsInputKey(Keys keyData)

Parameters

Type	Name	Description
System.Windows.Forms.Keys	keyData

Returns

Type	Description
System.Boolean

IsTextValid(String)

Declaration

protected virtual bool IsTextValid(string text)

Parameters

Type	Name	Description
System.String	text

Returns

Type	Description
System.Boolean

IsValidIndex(Int32)

Declaration

protected virtual bool IsValidIndex(int index)

Parameters

Type	Name	Description
System.Int32	index

Returns

Type	Description
System.Boolean

MoveSelelctionInPopupControl(Boolean)

Moves the current selection in the attached PopupControl.

Declaration

protected virtual void MoveSelelctionInPopupControl(bool up)

Parameters

Type	Name	Description
System.Boolean	up	Indicates whether to move up.

OnBeforePopup()

Called before the popup gets dropped down.

Declaration

protected virtual void OnBeforePopup()

OnBeginInit()

Declaration

protected virtual void OnBeginInit()

OnBorder3DStyleChanged(EventArgs)

Raises the Border3DStyleChanged event.

Declaration

protected virtual void OnBorder3DStyleChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e	An EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The OnBorder3DStyleChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Note to Inheritors: When overriding OnBorder3DStyleChanged in a derived class, be sure to call the base class's OnBorder3DStyleChanged method so that registered delegates receive the event.

OnBorderSidesChanged(EventArgs)

Raises the BorderSidesChanged event.

Declaration

protected virtual void OnBorderSidesChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e	An EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The OnBorderSidesChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Note to Inheritors: When overriding OmBorderSidesChanged in a derived class, be sure to call the base class's OnBorderSidesChanged method so that registered delegates receive the event.

OnDropDown(EventArgs)

Raises the Drop-Down event.

Declaration

protected virtual void OnDropDown(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e	An EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The OnDropDown method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Note to Inheritors: When overriding OnDropDown in a derived class, be sure to call the base class's OnDropDown method so that registered delegates receive the event.

OnDropDownStyleChanged(EventArgs)

Raises the DropDownStyleChanged event.

Declaration

protected virtual void OnDropDownStyleChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e	An EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see "Raising an Event".

The DropDownStyleChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Note to Inheritors: When overriding OnDropDownStyleChanged in a derived class, be sure to call the base class's OnDropDownStyleChanged method so that registered delegates receive the event.

OnEnabledChanged(EventArgs)

Declaration

protected override void OnEnabledChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnEndInit()

Declaration

protected virtual void OnEndInit()

OnEnter(EventArgs)

Declaration

protected override void OnEnter(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnFontChanged(EventArgs)

Font chnaged

Declaration

protected override void OnFontChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnGotFocus(EventArgs)

Declaration

protected override void OnGotFocus(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnHandleCreated(EventArgs)

Declaration

protected override void OnHandleCreated(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnHandleDestroyed(EventArgs)

Declaration

protected override void OnHandleDestroyed(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnKeyDown(KeyEventArgs)

Declaration

protected override void OnKeyDown(KeyEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.KeyEventArgs	e

OnKeyPress(KeyPressEventArgs)

Declaration

protected override void OnKeyPress(KeyPressEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.KeyPressEventArgs	e

OnLayout(LayoutEventArgs)

Declaration

protected override void OnLayout(LayoutEventArgs levent)

Parameters

Type	Name	Description
System.Windows.Forms.LayoutEventArgs	levent

OnLostFocus(EventArgs)

Declaration

protected override void OnLostFocus(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnMouseDown(MouseEventArgs)

Declaration

protected override void OnMouseDown(MouseEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.MouseEventArgs	e

OnMouseEnter(EventArgs)

Declaration

protected override void OnMouseEnter(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnMouseLeave(EventArgs)

Declaration

protected override void OnMouseLeave(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnMouseMove(MouseEventArgs)

Declaration

protected override void OnMouseMove(MouseEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.MouseEventArgs	e

OnMouseUp(MouseEventArgs)

Declaration

protected override void OnMouseUp(MouseEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.MouseEventArgs	e

OnMouseUpOnQuickSelect()

Declaration

protected virtual void OnMouseUpOnQuickSelect()

OnMouseWheel(MouseEventArgs)

Declaration

protected override void OnMouseWheel(MouseEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.MouseEventArgs	e

OnNewListItemKeyedIn(Int32)

Declaration

protected virtual bool OnNewListItemKeyedIn(int indexFound)

Parameters

Type	Name	Description
System.Int32	indexFound

Returns

Type	Description
System.Boolean

OnNoChangeDetectedOnPopupClosed()

Declaration

protected virtual void OnNoChangeDetectedOnPopupClosed()

OnPaint(PaintEventArgs)

Declaration

protected override void OnPaint(PaintEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.PaintEventArgs	e

OnPopupClosed(PopupClosedEventArgs)

Called when the popup is closed.

Declaration

protected virtual void OnPopupClosed(PopupClosedEventArgs e)

Parameters

Type	Name	Description
PopupClosedEventArgs	e

OnReadOnlyChanged(EventArgs)

Raises the ReadOnlyChanged event.

Declaration

protected virtual void OnReadOnlyChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e	An EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see "Raising an Event".

The ReadOnlyChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Note to Inheritors: When overriding OnReadOnlyChanged in a derived class, be sure to call the base class's OnReadOnlyChanged method so that registered delegates receive the event.

OnSelectionChangeCommitted(EventArgs)

Raises the SelectionChangeCommitted event.

Declaration

protected virtual void OnSelectionChangeCommitted(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e	An EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The OnSelectionChangeCommitted method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Note to Inheritors: When overriding OnSelectionChangeCommitted in a derived class, be sure to call the base class's OnSelectionChangeCommitted method so that registered delegates receive the event.

OnSelectionChangedOnPopupClose()

Declaration

protected virtual void OnSelectionChangedOnPopupClose()

OnSizeChanged(EventArgs)

Declaration

protected override void OnSizeChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnSystemColorsChanged(EventArgs)

Overridden. See System.Windows.Forms.Control.OnSystemColorsChanged(System.EventArgs).

Declaration

protected override void OnSystemColorsChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnTabStopChanged(EventArgs)

Declaration

protected override void OnTabStopChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OnTextBoxKeyUp(KeyEventArgs)

Declaration

protected virtual void OnTextBoxKeyUp(KeyEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.KeyEventArgs	e

OnThemeChanged(EventArgs)

Raises the ThemeChanged event.

Declaration

protected virtual void OnThemeChanged(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e	An EventArgs that contains the event data.

Remarks

The OnThemeChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Note to Inheritors: When overriding OnThemeChanged in a derived class, be sure to call the base class's OnThemeChanged method so that registered delegates receive the event.

OnValidated(EventArgs)

Declaration

protected override void OnValidated(EventArgs e)

Parameters

Type	Name	Description
System.EventArgs	e

OtherChangesMade()

Indicates whether another change was made except text changing in control.

Declaration

protected virtual bool OtherChangesMade()

Returns

Type	Description
System.Boolean	True if changes were detected; false otherwise.

PerformAllowNewText(Message)

Verifies whether new text is allowed to be entered from native message.

Declaration

public virtual bool PerformAllowNewText(Message m)

Parameters

Type	Name	Description
System.Windows.Forms.Message	m	The message.

Returns

Type	Description
System.Boolean	True if the message is handled.

PerformTextAutoComplete(KeyPressEventArgs)

Performs auto complete in the text area.

Declaration

protected virtual void PerformTextAutoComplete(KeyPressEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.KeyPressEventArgs	e	The arguments of the KeyPress event.

ProcessCmdKey(ref Message, Keys)

Declaration

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)

Parameters

Type	Name	Description
System.Windows.Forms.Message	msg
System.Windows.Forms.Keys	keyData

Returns

Type	Description
System.Boolean

ProcessDDMouseDown()

Declaration

protected virtual void ProcessDDMouseDown()

ProcessDDMouseDown(MouseEventArgs)

Declaration

protected virtual void ProcessDDMouseDown(MouseEventArgs e)

Parameters

Type	Name	Description
System.Windows.Forms.MouseEventArgs	e

ProcessDialogKey(Keys)

Declaration

protected override bool ProcessDialogKey(Keys keyData)

Parameters

Type	Name	Description
System.Windows.Forms.Keys	keyData

Returns

Type	Description
System.Boolean

ProcessMouseMove(MouseEventArgs, Boolean)

Processes mouse moves on the combo-box and textbox area.

Declaration

protected virtual void ProcessMouseMove(MouseEventArgs e, bool fromTextBox)

Parameters

Type	Name	Description
System.Windows.Forms.MouseEventArgs	e	The event args of the MouseMove event.
System.Boolean	fromTextBox	Indicates whether this was called due to mouse move in the text area or combo.

ProcessPopupControlMouseMove(Object, MouseEventArgs)

Declaration

protected virtual void ProcessPopupControlMouseMove(object sender, MouseEventArgs e)

Parameters

Type	Name	Description
System.Object	sender
System.Windows.Forms.MouseEventArgs	e

RaiseSelectionChangeCommitted()

Raises the SelectionChangeCommitted event.

Declaration

public void RaiseSelectionChangeCommitted()

Remarks

The event will be fired usually when the user commits selection change. You could use this method to raise an event manually for a custom scenario.

ResetBackColor()

Resets the System.Windows.Forms.Control.BackColor property to its default value.

Declaration

public override void ResetBackColor()

ResetDropDownWidth()

Resets the DropDownWidth property's value to its default.

Declaration

public void ResetDropDownWidth()

ResetFlatBorderColor()

Declaration

protected void ResetFlatBorderColor()

ResetToLatestCommittedText()

Declaration

protected virtual void ResetToLatestCommittedText()

SetBoundsCore(Int32, Int32, Int32, Int32, BoundsSpecified)

Declaration

protected override void SetBoundsCore(int x, int y, int width, int height, BoundsSpecified specified)

Parameters

Type	Name	Description
System.Int32	x
System.Int32	y
System.Int32	width
System.Int32	height
System.Windows.Forms.BoundsSpecified	specified

SetNeedLayout(Boolean)

Forces laying out of the combo elements within the next Paint Message handler.

Declaration

protected virtual void SetNeedLayout(bool needLayout)

Parameters

Type	Name	Description
System.Boolean	needLayout	True to force; False to prevent layout.

SetPopupText(String)

Declaration

protected virtual void SetPopupText(string value)

Parameters

Type	Name	Description
System.String	value

SetSelectedText(String, Int32)

Declaration

protected virtual void SetSelectedText(string text, int foundIndex)

Parameters

Type	Name	Description
System.String	text
System.Int32	foundIndex

SetText(String, Boolean)

Declaration

protected virtual void SetText(string newValue, bool fireChangeEvent)

Parameters

Type	Name	Description
System.String	newValue
System.Boolean	fireChangeEvent

SetTextBoxBounds(Rectangle)

Declaration

protected virtual void SetTextBoxBounds(Rectangle rect)

Parameters

Type	Name	Description
System.Drawing.Rectangle	rect

ShouldSerializeBackColor()

Declaration

protected bool ShouldSerializeBackColor()

Returns

Type	Description
System.Boolean

ShouldSerializeDropDownWidth()

Indicates whether the DropDownWidth property's value is the default.

Declaration

public bool ShouldSerializeDropDownWidth()

Returns

Type	Description
System.Boolean	True if the value is not the default; false otherwise.

ShouldSerializeFlatBorderColor()

Declaration

protected bool ShouldSerializeFlatBorderColor()

Returns

Type	Description
System.Boolean

ShowPopup()

Shows the drop-down.

Declaration

protected virtual void ShowPopup()

UnInitTextBox()

Declaration

protected virtual void UnInitTextBox()

UpdateDropDownButtonBounds()

Updates the bounds of the drop-down button bounds.

Declaration

protected virtual void UpdateDropDownButtonBounds()

Remarks

Sets the bounds based on the value returned by the GetComboBoxDropDownWidth() method.

UpdateEditPortionBounds(Int32)

Updates the internal textbox's bounds and visibility based on the DropDownStyle.

Declaration

protected virtual void UpdateEditPortionBounds(int textAreaHeight)

Parameters

Type	Name	Description
System.Int32	textAreaHeight	The height of the text area.

UpdateLayout(Graphics)

Declaration

public void UpdateLayout(Graphics g)

Parameters

Type	Name	Description
System.Drawing.Graphics	g

UpdatePopupBounds()

Declaration

protected virtual void UpdatePopupBounds()

UpdatePopupControl()

Updates the attached popup control based on the current Text property.

Declaration

public virtual void UpdatePopupControl()

Remarks

Call this method to update the popup list box, for example, with the latest text value that the user might have entered. This is useful when you enable auto completion in the text area and force the list box's SelectedValue to be updated to the latest text value in this control's Validated event.

UpdatePopupControlBounds()

Updates the attached PopupControl's bounds.

Declaration

protected virtual void UpdatePopupControlBounds()

Remarks

The base class updates the PopupControl's bounds and visibility based on the DropDownStyle settings.

UpdatePopupControlRelationship()

Updates the attached PopupControl's parent-child relationship.

Declaration

protected virtual void UpdatePopupControlRelationship()

Remarks

If in ComboBoxStyle.Simple mode, the base class implementation parents the Popup Control to the combo itself. Otherwise, it parents the PopupContainer to the Popup Control.

UpdateText(Boolean)

Updates the Text property based on the PopupControl's selected value.

Declaration

public virtual bool UpdateText(bool fireEvent)

Parameters

Type	Name	Description
System.Boolean	fireEvent	Indicates whether the SelectionChangeCommitted event should be fired if the text is changed.

Returns

Type	Description
System.Boolean	True if the SelectionChangeCommitted event was fired; False otherwise.

Remarks

You normally do not have to call this method. However when you programmatically update the SelectedValue of a plug in the list control, you might have to call this method to update the combo's text based on that new value.

WndProc(ref Message)

Declaration

protected override void WndProc(ref Message m)

Parameters

Type	Name	Description
System.Windows.Forms.Message	m

Events

Border3DStyleChanged

Occurs when border's 3D style is changed.

Declaration

public event EventHandler Border3DStyleChanged

Event Type

Type	Description
System.EventHandler

BorderSidesChanged

Fired when BorderSides are changed.

Declaration

public event EventHandler BorderSidesChanged

Event Type

Type	Description
System.EventHandler

DropDown

Occurs before the drop-down portion is shown.

Declaration

public event EventHandler DropDown

Event Type

Type	Description
System.EventHandler

DropDownStyleChanged

Occurs when the DropDownStyle of the combo changes.

Declaration

public event EventHandler DropDownStyleChanged

Event Type

Type	Description
System.EventHandler

ReadOnlyChanged

Occurs when the ReadOnly property of the combo changes.

Declaration

public event EventHandler ReadOnlyChanged

Event Type

Type	Description
System.EventHandler

SelectionChangeCommitted

Occurs when the user selects a new text for the combo in one of many possible ways.

Declaration

public event EventHandler SelectionChangeCommitted

Event Type

Type	Description
System.EventHandler

Remarks

This event will be fired for the following cases:

• When the user selects a new item in the list box by clicking or pressing Enter.
• When the user Tabs out of the combo after changing the current text and Validation was successful.

ThemeChanged

Fired when the ThemesEnabled property changes.

Declaration

public event EventHandler ThemeChanged

Event Type

Type	Description
System.EventHandler

Explicit Interface Implementations

INonClientPaintingSupport.NonClientPaint(PaintEventArgs, Rectangle, Rectangle)

Declaration

IntPtr INonClientPaintingSupport.NonClientPaint(PaintEventArgs e, Rectangle displayRect, Rectangle windowRectInScreen)

Parameters

Type	Name	Description
System.Windows.Forms.PaintEventArgs	e
System.Drawing.Rectangle	displayRect
System.Drawing.Rectangle	windowRectInScreen

Returns

Type	Description
System.IntPtr

ISupportOffice2007Theme.EnableOffice2007Style()

Declaration

void ISupportOffice2007Theme.EnableOffice2007Style()

IThemedControl.ThemesEnabled

Indicates whether themes are enabled for this control.

Declaration

bool IThemedControl.ThemesEnabled { get; set; }

Returns

Type	Description
System.Boolean

IVisualStyle.VisualTheme

Declaration

string IVisualStyle.VisualTheme { get; set; }

Returns

Type	Description
System.String

Implements

IThemedControl

System.ComponentModel.ISupportInitialize

INonClientPaintingSupport

ISupportOffice2007Theme

IVisualStyle