Class GridVirtualizingCellRendererBase<T1, T2>

VirtualizingCellRendererBase is an abstract base class for cell renderer classes that need live views displayed in a cell. You can derive from this class and provide the type of the view you want to show inside cells as type parameter. The class provides strong typed virtual methods for initializing Content of the cell and arranging the cell visuals.

The class manages the creation of cells view objects when the cell is scrolled into view and also unloading of the views. The class offers an optimization in which Views can be recycled when AllowRecycle is set. In this case when a cell is scrolled out of view it is moved into a recycle bin and the next time a new view is scrolled into view the element is recovered from the recycle bin and reinitialized with the new Content of the cell.

Updates to appearance and Content of child elements, creation and unloading of views will not trigger layout or render calls in parent canvas.

Inheritance

System.Object

GridCellRendererBase

GridVirtualizingCellRendererBase<T1, T2>

GridCaptionSummaryCellRenderer

GridCellSwitchRenderer

GridCellTemplateRenderer

GridGroupSummaryCellRenderer

GridHeaderCellRenderer

GridImageCellRenderer

GridRowHeaderCellRenderer

GridStackedHeaderCellRenderer

GridTableSummaryCellRenderer

GridVirtualizingCellRenderer<T1, T2>

Implements

IGridCellRenderer

System.IDisposable

Inherited Members

GridCellRendererBase.CanUpdateBinding(DataColumnBase)

GridCellRendererBase.CurrentCellElement

GridCellRendererBase.CurrentCellIndex

GridCellRendererBase.CurrentCellRendererElement

GridCellRendererBase.DataGrid

GridCellRendererBase.Dispose()

GridCellRendererBase.GetControlValue()

GridCellRendererBase.HasCurrentCellState

GridCellRendererBase.IGridCellRenderer.UpdateColumnInfo(DataColumnBase)

GridCellRendererBase.IsEditable

GridCellRendererBase.IsFocusable

GridCellRendererBase.OnUpdateCellValue(DataColumnBase)

GridCellRendererBase.PrepareViews(DataColumnBase)

GridCellRendererBase.RefreshDisplayValue(DataColumnBase)

GridCellRendererBase.ResetCurrentCellState()

GridCellRendererBase.SetCellStyle(DataColumnBase)

GridCellRendererBase.SetControlValue(Object)

GridCellRendererBase.SetCurrentCellState(RowColumnIndex, CellElement, Boolean)

GridCellRendererBase.SetFocus(Boolean)

GridCellRendererBase.SetFocus(View, Boolean)

GridCellRendererBase.SupportsRenderOptimization

GridCellRendererBase.UnloadViews(DataColumnBase)

GridCellRendererBase.UpdateCellStyle(DataColumnBase)

GridCellRendererBase.UpdateCellValue(DataColumnBase)

GridCellRendererBase.UpdateColumnInfo(DataColumnBase)

GridCellRendererBase.UpdateCurrentCellState(View, Boolean)

Namespace: Syncfusion.SfDataGrid.XForms

Assembly: Syncfusion.SfDataGrid.XForms.dll

Syntax

public abstract class GridVirtualizingCellRendererBase<T1, T2> : GridCellRendererBase, IGridCellRenderer, IDisposable where T1 : View where T2 : View

Type Parameters

Name	Description
T1	The type of the UIElement that should be placed inside cells in display mode.
T2	The type of the UIElement that should be placed inside cells in edit mode.

Constructors

GridVirtualizingCellRendererBase()

Initializes a new instance of the GridVirtualizingCellRendererBase<T1, T2> class.

Declaration

protected GridVirtualizingCellRendererBase()

Fields

displayRecycleBin

Recycles the display view elements for cells that were scrolled out of view.

Declaration

protected VirtualizingCellUIElementBin<T1> displayRecycleBin

Field Value

Type
Syncfusion.SfDataGrid.XForms.VirtualizingCellUIElementBin<T1>

editRecycleBin

Recycles the edit view elements for cells that were scrolled out of view.

Declaration

protected VirtualizingCellUIElementBin<T2> editRecycleBin

Field Value

Type
Syncfusion.SfDataGrid.XForms.VirtualizingCellUIElementBin<T2>

Properties

AllowRecycle

Gets or sets a value indicating whether views can be recycled when scrolled out of view. In this case when a cell is scrolled out of view it is moved into a recycle bin and the next time a new element is scrolled into view the element is recovered from the recycle bin and reinitialized with the new Content of the cell.

Declaration

public bool AllowRecycle { get; set; }

Property Value

Type	Description
System.Boolean	True if elements can be recycled when scrolled out of view, otherwise false. The default value is true.

Methods

BeginEdit(RowColumnIndex, CellElement, GridColumn, Object)

This method fires when editing in the current cell begins.

Declaration

public override bool BeginEdit(RowColumnIndex rowColumnIndex, CellElement cellElement, GridColumn column, object rowData)

Parameters

Type	Name	Description
RowColumnIndex	rowColumnIndex	The row column index of the cell which is in edit mode.
CellElement	cellElement	The UIElement of the cell which is in edit mode.
GridColumn	column	The corresponding grid column of the cell which is in edit mode.
System.Object	rowData	The corresponding record of the row which is in edit mode.

Returns

Type	Description
System.Boolean	Returns a value indicating whether the cell enters into the editing mode or not.

Overrides

GridCellRendererBase.BeginEdit(RowColumnIndex, CellElement, GridColumn, Object)

ClearRecycleBin()

Clears the recycle bin. The cell element will be stored for recycling purpose, when the cell element is scrolled out of view. This method clears all the cell elements which are stored for recycling purpose.

Declaration

public override void ClearRecycleBin()

Overrides

GridCellRendererBase.ClearRecycleBin()

Remarks

This method clears both the display recycle bin which stores the display cell elements and edit recycle bin which stores the edit cell elements.

CommitCellValue(Boolean)

Commits the edited value to the underlying data.

Declaration

public override void CommitCellValue(bool isNewValue)

Parameters

Type	Name	Description
System.Boolean	isNewValue	A value indicating whether the edited value is new value.

Overrides

GridCellRendererBase.CommitCellValue(Boolean)

Dispose(Boolean)

Releases the unmanaged resources used by the component and optionally releases the managed resources.

Declaration

protected override void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing	if true - release both managed and unmanaged resources; if false - release only unmanaged resources.

Overrides

GridCellRendererBase.Dispose(Boolean)

EndEdit(DataColumnBase, Object, Boolean)

This method fires when the editing in the current cell is ended.

Declaration

public override bool EndEdit(DataColumnBase dataColumn, object record, bool canResetBinding = false)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The corresponding data column of the cell, which leaves the edit mode.
System.Object	record	The underlying data of the cell, which leaves the edit mode.
System.Boolean	canResetBinding	The value indicating whether to reset the binding or not.

Returns

Type	Description
System.Boolean	A boolean value indicating whether the current cell has focus.

Overrides

GridCellRendererBase.EndEdit(DataColumnBase, Object, Boolean)

InitializeDisplayView(DataColumnBase, T1)

Initializes the column element of a Syncfusion.SfDataGrid.XForms.DataColumn object with the given view and required values.

Declaration

public void InitializeDisplayView(DataColumnBase dataColumn, T1 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column containing the details of the column.
T1	view	The child view to be hosted inside the column element.

InitializeEditView(DataColumnBase, T2)

Initializes the edit column element of a Syncfusion.SfDataGrid.XForms.DataColumn object with the given view and required values.

Declaration

public void InitializeEditView(DataColumnBase dataColumn, T2 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column containing the details of the column.
T2	view	The child view to be hosted inside the column element.

OnCreateDisplayUIView()

Creates a new display view based on the type parameter.

Declaration

protected virtual T1 OnCreateDisplayUIView()

Returns

Type	Description
T1	A view of type given in the type parameter.

OnCreateEditUIView()

Creates a new view for the edit mode of cell.

Declaration

protected virtual T2 OnCreateEditUIView()

Returns

Type	Description
T2	Returns the new view for edit mode of cell.

OnEnteredEditMode(DataColumnBase, View)

Invoked when the cell is being entered on the edit mode.

Declaration

protected virtual void OnEnteredEditMode(DataColumnBase dataColumn, View currentRendererElement)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The corresponding data column being entered on the edit mode.
Xamarin.Forms.View	currentRendererElement	The corresponding renderer element in edit mode.

OnInitializeDisplayView(DataColumnBase, T1)

Initializes the column element of a Syncfusion.SfDataGrid.XForms.DataColumn object with the given view and required values.

Declaration

public abstract void OnInitializeDisplayView(DataColumnBase dataColumn, T1 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column containing the details of the column.
T1	view	The child view to be hosted inside the column element.

OnInitializeEditView(DataColumnBase, T2)

Initializes the edit column element of a Syncfusion.SfDataGrid.XForms.DataColumn object with the given view and required values.

Declaration

public virtual void OnInitializeEditView(DataColumnBase dataColumn, T2 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column containing the details of the column.
T2	view	The child view to be hosted inside the column element.

OnLayout(RowColumnIndex, View, Int32, Int32, Int32, Int32)

Called from the parent to arrange the GridCell's children view(s).

Declaration

protected override void OnLayout(RowColumnIndex rowColumnIndex, View view, int left, int top, int right, int bottom)

Parameters

Type	Name	Description
RowColumnIndex	rowColumnIndex	Row Column Index of the cell.
Xamarin.Forms.View	view	Corresponding view.
System.Int32	left	left end of the cell for arranging the view.
System.Int32	top	top value for arranging the view.
System.Int32	right	right end of the cell for arranging the view.
System.Int32	bottom	bottom value for arranging the view.

Overrides

GridCellRendererBase.OnLayout(RowColumnIndex, View, Int32, Int32, Int32, Int32)

OnMeasure(RowColumnIndex, View, Int32, Int32)

Called from the parent to Measure the GridCell's children view(s).

Declaration

protected override void OnMeasure(RowColumnIndex rowColumnIndex, View view, int widthMeasureSpec, int heightMeasureSpec)

Parameters

Type	Name	Description
RowColumnIndex	rowColumnIndex	Row Column Index of the cell.
Xamarin.Forms.View	view	Corresponding view.
System.Int32	widthMeasureSpec	Corresponding width for measuring the view size.
System.Int32	heightMeasureSpec	Corresponding height for measuring the view size.

Overrides

GridCellRendererBase.OnMeasure(RowColumnIndex, View, Int32, Int32)

OnPrepareViews(DataColumnBase)

Called from PrepareViews(DataColumnBase) to prepare the GridCell's children view(s). VirtualizingCellRendererBase overrides this method and creates new views and wires them with the parent cells control.

Declaration

protected override sealed CellElement OnPrepareViews(DataColumnBase dataColumn)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The DataColumn containing the details of the column.

Returns

Type	Description
CellElement	Returns the columnElement of the cell.

Overrides

GridCellRendererBase.OnPrepareViews(DataColumnBase)

OnRefreshDisplayValue(DataColumnBase)

Called from RefreshDisplayValue(DataColumnBase) to refresh the display value of the column element.

Declaration

protected override void OnRefreshDisplayValue(DataColumnBase dataColumn)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The dataColumn containing the details of the column.

Overrides

GridCellRendererBase.OnRefreshDisplayValue(DataColumnBase)

OnSetCellStyle(DataColumnBase)

Called from SetCellStyle(DataColumnBase) to set the style for the column element in a Syncfusion.SfDataGrid.XForms.DataColumn.

Declaration

protected override void OnSetCellStyle(DataColumnBase dataColumn)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column.

Overrides

GridCellRendererBase.OnSetCellStyle(DataColumnBase)

OnUnloadViews(DataColumnBase)

Called from UnloadViews(DataColumnBase) after a cell is scrolled out of view. VirtualizingCellRendererBase overrides this method and either removes the cell renderer visuals from the parent canvas or hide them and reuse it later in same canvas depending on whether GridVirtualizingCellRendererBase.AllowRecycle was set.

Declaration

protected override void OnUnloadViews(DataColumnBase dataColumn)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The DataColumn containing the details of the column.

Overrides

GridCellRendererBase.OnUnloadViews(DataColumnBase)

OnUpdateCellStyle(DataColumnBase)

Called from UpdateCellStyle(DataColumnBase) to update the cell style for the column element in a Syncfusion.SfDataGrid.XForms.DataColumn.

Declaration

protected override void OnUpdateCellStyle(DataColumnBase dataColumn)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column.

Overrides

GridCellRendererBase.OnUpdateCellStyle(DataColumnBase)

OnUpdateColumnInfo(DataColumnBase)

Called from UpdateColumnInfo(DataColumnBase) to update the value of the Cell view corresponding to GridColumn. In our control we are reusing the cell views for horizontal scrolling. Hence we need to update the value of the cell view.

Declaration

protected override sealed void OnUpdateColumnInfo(DataColumnBase dataColumn)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The dataColumn containing the details of the column.

Overrides

GridCellRendererBase.OnUpdateColumnInfo(DataColumnBase)

OnUpdateDisplayValue(DataColumnBase, T1)

Updates the column element of a Syncfusion.SfDataGrid.XForms.DataColumn object with the given view and required values.

Declaration

public abstract void OnUpdateDisplayValue(DataColumnBase dataColumn, T1 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column containing the details of the column.
T1	view	The child view to be updated inside the column element.

ResumeBinding(DataColumnBase, T1)

Resumes the binding value.

Declaration

protected virtual void ResumeBinding(DataColumnBase dataColumn, T1 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	DataColumnBase instance.
T1	view	current view.

SuspendBinding(DataColumnBase, T1)

Suspends the binding value.

Declaration

protected virtual void SuspendBinding(DataColumnBase dataColumn, T1 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	DataColumnBase instance.
T1	view	current view.

UnwireEditUIElement(T2)

Unwire the edit element to the view.

Declaration

protected virtual void UnwireEditUIElement(T2 editElement)

Parameters

Type	Name	Description
T2	editElement	The edit element .

UpdateColumnElement(DataColumnBase)

Updates the column element of the passed dataColumn.

Declaration

protected virtual CellElement UpdateColumnElement(DataColumnBase dataColumn)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column.

Returns

Type	Description
CellElement	The column element.

UpdateDisplayValue(DataColumnBase, T1)

Updates the column element of a Syncfusion.SfDataGrid.XForms.DataColumn object with the given view and required values.

Declaration

public void UpdateDisplayValue(DataColumnBase dataColumn, T1 view)

Parameters

Type	Name	Description
Syncfusion.SfDataGrid.XForms.DataColumnBase	dataColumn	The data column containing the details of the column.
T1	view	The child view to be updated inside the column element.

WireEditUIElement(T2)

Wires the edit element to the view.

Declaration

protected virtual void WireEditUIElement(T2 editElement)

Parameters

Type	Name	Description
T2	editElement	The edit element.

Implements

IGridCellRenderer

System.IDisposable