[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]
Namespace:
System.Windows.Input
Assembly:
PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
Visual Basic (Declaration)
Public Class InputBinding _
Inherits Freezable _
Implements ICommandSource
Dim instance As InputBinding
public class InputBinding : Freezable,
ICommandSource
public ref class InputBinding : public Freezable,
ICommandSource
type InputBinding =
class
inherit Freezable
interface ICommandSource
end
XAML Object Element Usage
<inputBindingDerivedClass…/>
XAML Values
- inputBindingDerivedClass
A derived class of InputBinding that supports object element syntax, such as KeyBinding or MouseBinding. See Remarks.
You can specify that user input invokes a command by creating a InputBinding. When the user performs the specified input, the ICommand that is set to the Command property is executed.
You can specify that the InputBinding invokes a command that is defined on an object by creating a binding on the Command, CommandParameter, and CommandTarget properties. This enables you to define a custom command and associate it with user input. For more information, see the second example in the Examples section.
An InputBinding can be defined on a specific object or at the class level by registering a RegisterClassInputBinding with the CommandManager.
The InputBinding class itself does not support XAML usage because it does not expose a public default constructor (there is a default constructor, but it is protected). However, derived classes can expose a public constructor and therefore can set properties on the derived class that are inherited from InputBinding with a XAML usage. Two existing InputBinding-derived classes that can be instantiated in XAML and can set properties in XAML are KeyBinding and MouseBinding. The typical property in WPF programming that is set in XAML and takes one or more InputBinding objects as values is the UIElement..::.InputBindings property.
The following example shows how to use a KeyBinding to bind a KeyGesture to the Open command. When the key gesture is performed, the Open command is invoked.
<Window.InputBindings>
<KeyBinding Key="B"
Modifiers="Control"
Command="ApplicationCommands.Open" />
</Window.InputBindings>
The following examples show how to bind a custom command to InputBinding objects. These examples create an application that enables the user to change the background color by performing one of the following actions:
The first example creates a class named SimpleDelegateCommand. This class accepts a delegate so that the object creating the command can define the action that occurs when the command executes. SimpleDelegateCommand also defines properties that specify what key and mouse input invokes the command. GestureKey and GestureModifier specify the keyboard input; MouseGesture specifies the mouse input.
' Create a class that implements ICommand and accepts a delegate.
Public Class SimpleDelegateCommand
Implements ICommand
' Specify the keys and mouse actions that invoke the command.
Private _GestureKey As Key
Private _GestureModifier As ModifierKeys
Private _MouseGesture As MouseAction
Public Property GestureKey() As Key
Get
Return _GestureKey
End Get
Set(ByVal value As Key)
_GestureKey = value
End Set
End Property
Public Property GestureModifier() As ModifierKeys
Get
Return _GestureModifier
End Get
Set(ByVal value As ModifierKeys)
_GestureModifier = value
End Set
End Property
Public Property MouseGesture() As MouseAction
Get
Return _MouseGesture
End Get
Set(ByVal value As MouseAction)
_MouseGesture = value
End Set
End Property
Private _executeDelegate As Action(Of Object)
Public Sub New(ByVal executeDelegate As Action(Of Object))
_executeDelegate = executeDelegate
End Sub
Public Sub Execute(ByVal parameter As Object) _
Implements ICommand.Execute
_executeDelegate(parameter)
End Sub
Public Function CanExecute(ByVal parameter As Object) As Boolean _
Implements ICommand.CanExecute
Return True
End Function
Public Event CanExecuteChanged As EventHandler _
Implements ICommand.CanExecuteChanged
End Class
// Create a class that implements ICommand and accepts a delegate.
public class SimpleDelegateCommand : ICommand
{
// Specify the keys and mouse actions that invoke the command.
public Key GestureKey { get; set; }
public ModifierKeys GestureModifier { get; set; }
public MouseAction MouseGesture { get; set; }
Action<object> _executeDelegate;
public SimpleDelegateCommand(Action<object> executeDelegate)
{
_executeDelegate = executeDelegate;
}
public void Execute(object parameter)
{
_executeDelegate(parameter);
}
public bool CanExecute(object parameter) { return true; }
public event EventHandler CanExecuteChanged;
}
The following example creates and initializes the ColorChangeCommand, which is a SimpleDelegateCommand. The example also defines the method that executes when the command is invoked and sets the GestureKey, GestureModifier, and MouseGesture properties. An application would call the InitializeCommand method when the program begins, such as in the constructor of a Window.
Public ReadOnly Property ChangeColorCommand() As SimpleDelegateCommand
Get
Return _changeColorCommand
End Get
End Property
Private _changeColorCommand As SimpleDelegateCommand
Private originalColor As Brush, alternateColor As Brush
Private Sub InitializeCommand()
originalColor = Me.Background
_changeColorCommand = New SimpleDelegateCommand(Function(x) Me.ChangeColor(x))
DataContext = Me
_changeColorCommand.GestureKey = Key.C
_changeColorCommand.GestureModifier = ModifierKeys.Control
_changeColorCommand.MouseGesture = MouseAction.RightClick
End Sub
' Switch the Background color between
' the original and selected color.
Private Function ChangeColor(ByVal colorString As Object) As Integer
If colorString Is Nothing Then
Return 0
End If
Dim newColor As Color = DirectCast(ColorConverter.ConvertFromString(DirectCast(colorString, [String])), Color)
alternateColor = New SolidColorBrush(newColor)
If Brush.Equals(Me.Background, originalColor) Then
Me.Background = alternateColor
Else
Me.Background = originalColor
End If
Return 0
End Function
public SimpleDelegateCommand ChangeColorCommand
{
get { return changeColorCommand; }
}
private SimpleDelegateCommand changeColorCommand;
private void InitializeCommand()
{
originalColor = this.Background;
changeColorCommand = new SimpleDelegateCommand(x => this.ChangeColor(x));
DataContext = this;
changeColorCommand.GestureKey = Key.C;
changeColorCommand.GestureModifier = ModifierKeys.Control;
ChangeColorCommand.MouseGesture = MouseAction.RightClick;
}
private Brush originalColor, alternateColor;
// Switch the Background color between
// the original and selected color.
private void ChangeColor(object colorString)
{
if (colorString == null)
{
return;
}
Color newColor =
(Color)ColorConverter.ConvertFromString((String)colorString);
alternateColor = new SolidColorBrush(newColor);
if (this.Background == originalColor)
{
this.Background = alternateColor;
}
else
{
this.Background = originalColor;
}
}
Finally, the following example creates the user interface. The example adds a KeyBinding and a MouseBinding to a StackPanel that contains a Button and a ListBox. When the user selects an item in the ListBox, he or she can change the color of the background to the selected color. In each case, the CommandTarget property is bound to the selected item in the ListBox and the Command property is bound the ColorChangeCommand. The KeyBinding..::.Key, KeyBinding..::.Modifiers, and MouseBinding..::.MouseAction properties are bound to the corresponding properties on the SimpleDelegateCommand class.
<StackPanel Background="Transparent">
<StackPanel.InputBindings>
<KeyBinding Command="{Binding ChangeColorCommand}"
CommandParameter="{Binding ElementName=colorPicker, Path=SelectedItem}"
Key="{Binding ChangeColorCommand.GestureKey}"
Modifiers="{Binding ChangeColorCommand.GestureModifier}"/>
<MouseBinding Command="{Binding ChangeColorCommand}"
CommandParameter="{Binding ElementName=colorPicker, Path=SelectedItem}"
MouseAction="{Binding ChangeColorCommand.MouseGesture}"/>
</StackPanel.InputBindings>
<Button Content="Change Color"
Command="{Binding ChangeColorCommand}"
CommandParameter="{Binding ElementName=colorPicker, Path=SelectedItem}">
</Button>
<ListBox Name="colorPicker"
Background="Transparent"
xmlns:sys="clr-namespace:System;assembly=mscorlib">
<sys:String>Red</sys:String>
<sys:String>Green</sys:String>
<sys:String>Blue</sys:String>
<sys:String>Yellow</sys:String>
<sys:String>Orange</sys:String>
<sys:String>Purple</sys:String>
</ListBox>
</StackPanel>
System..::.Object
System.Windows.Threading..::.DispatcherObject
System.Windows..::.DependencyObject
System.Windows..::.Freezable
System.Windows.Input..::.InputBinding
System.Windows.Input..::.KeyBinding
System.Windows.Input..::.MouseBinding
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 4, 3.5, 3.0
.NET Framework Client Profile
Supported in: 4
Reference
Other Resources