Restriction in WPF Numeric UpDown

18 Nov 20186 minutes to read

This section explains how to set the value and restrict the minimum and maximum value of the WPF Numeric UpDown control.

Value

The Value property is used to set the value of the WPF Numeric UpDown control. The default value is 0 (or null when UseNullOption is enabled).

XAML

<syncfusion:UpDown Name="upDown" Height="25" Width="90" Value="10" />

C#

UpDown updown = new UpDown();
updown.Height = 25;
updown.Width = 90;
updown.Value = 10;
grid.Children.Add(updown);

Value event

The WPF Numeric UpDown control notifies value changes through the ValueChanged and ValueChanging events. Use the OldValue and NewValue properties of ValueChanged to read the new and old values. In the ValueChanging event, set the Cancel property on the event argument to prevent the change.

XAML

<syncfusion:UpDown Name="upDown"
                  ValueChanged="Up_ValueChanged"
                  ValueChanging="Up_ValueChanging"
                  Height="25" Width="90"/>

C#

updown.ValueChanged += Up_ValueChanged;
updown.ValueChanging += Up_ValueChanging;

private void Up_ValueChanging(object sender, Syncfusion.Windows.Shared.ValueChangingEventArgs e)
{
    // Cancel the value change
    e.Cancel = true;
}

private void Up_ValueChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    // Get old and new value
    var newValue = e.NewValue;
    var oldValue = e.OldValue;
}

Null value

The WPF Numeric UpDown control accepts null values. When the Value is set to null, the control shows 0 by default. To display a different numerical value when Value is null, set the NullValue property. The UseNullOption property must be enabled for NullValue to take effect.

XAML

<syncfusion:UpDown Name="upDown" Height="25" Width="90" Value="{x:Null}" NullValue="2" UseNullOption="True" />

C#

updown.UseNullOption = true;
updown.Value = null;
updown.NullValue = 2;

Watermark

The NullValueText property enables the WPF Numeric UpDown control to display watermark text instead of a numeric value when Value is null. The UseNullOption property must be enabled for NullValueText to take effect.

XAML

<syncfusion:UpDown Name="upDown" Height="25" Width="90" Value="{x:Null}" NullValueText="Enter a value" UseNullOption="True" />

C#

updown.Value = null;
updown.NullValueText = "Enter a value";

NOTE

The UseNullOption property must be enabled if you want to see the NullValue or NullValueText in WPF Numeric UpDown control. If both NullValue and NullValueText is specified, you will see only NullValue but not NullValueText.

Minimum and Maximum value

The value of the WPF Numeric UpDown control can be restricted to a maximum and minimum limit. The spin button increments or decrements the value by mouse interaction; once the increment or decrement reaches the predefined maximum or minimum, the value stops changing.

Similarly, the keyboard does not allow you to enter a value above or below the predefined maximum or minimum.

• MaxValue - The MaxValue property sets the maximum value the control accepts. The default value is double.MaxValue.
• MinValue - The MinValue property sets the minimum value the control accepts. The default value is double.MinValue.

XAML

<syncfusion:UpDown Name="upDown" Height="25" Width="90" MinValue="0" MaxValue="100" />

C#

updown.MaxValue = 100;
updown.MinValue = 0;

Minimum and Minimum validation

You can choose when to validate against the maximum and minimum limits while changing values by using the MaxValidation and MinValidation properties. The accepted values are OnKeyPress and OnLostFocus.

• OnKeyPress - The value is validated as soon as a key is pressed, so an invalid input is not accepted at all.
• OnLostFocus - The value is accepted during editing but is validated when the control loses focus. If the value is greater than MaxValue or less than MinValue, it is automatically reset to the corresponding limit.

MaxValueOnExceedMaxDigit

When you enter an input greater than the specified maximum, the MaxValueOnExceedMaxDigit property decides whether the entered value is reset to the maximum or retained as a partial value. For example, if MaxValue is 100 and you enter 200, the value is reset to 100 when MaxValueOnExceedMaxDigit is true; when false, 20 is retained and the last digit (0) is ignored.

MinValueOnExceedMinDigit

Similarly, when you enter an input less than the specified minimum, the MinValueOnExceedMinDigit property decides whether the entered value is reset to the minimum or retained as a partial value

XAML

<syncfusion:UpDown Name="upDown" Height="25" Width="90" MinValueOnExceedMinDigit="True" MaxValueOnExceedMaxDigit="True" MaxValidation="OnKeyPress" MinValidation="OnKeyPress" MinValue="0" MaxValue="100" />

C#

updown.MaxValidation = MaxValidation.OnKeyPress;
updown.MinValidation = MinValidation.OnKeyPress;
updown.MinValueOnExceedMinDigit = true;
updown.MaxValueOnExceedMaxDigit = true;

AllowEdit

The AllowEdit property is used to restrict the editing in WPF Numeric UpDown control by setting it’s value to False. The default value is True.

XAML

<syncfusion:UpDown Name="upDown" Height="25" Width="90" AllowEdit="False" MinValue="0" MaxValue="100" />

C#

updown.AllowEdit = false;