InputBinding Class

 

Represents a binding between an InputGesture and a command. The command is potentially a RoutedCommand.

Namespace:   System.Windows.Input
Assembly:  PresentationCore (in PresentationCore.dll)

System.Object
  System.Windows.Threading.DispatcherObject
    System.Windows.DependencyObject
      System.Windows.Freezable
        System.Windows.Input.InputBinding
          System.Windows.Input.KeyBinding
          System.Windows.Input.MouseBinding

Public Class InputBinding
	Inherits Freezable
	Implements ICommandSource

NameDescription
System_CAPS_protmethodInputBinding()

Provides base initialization for classes derived from InputBinding.

System_CAPS_pubmethodInputBinding(ICommand, InputGesture)

Initializes a new instance of the InputBinding class with the specified command and input gesture.

NameDescription
System_CAPS_pubpropertyCanFreeze

Gets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.)

System_CAPS_pubpropertyCommand

Gets or sets the ICommand associated with this input binding.

System_CAPS_pubpropertyCommandParameter

Gets or sets the command-specific data for a particular command.

System_CAPS_pubpropertyCommandTarget

Gets or sets the target element of the command.

System_CAPS_pubpropertyDependencyObjectType

Gets the DependencyObjectType that wraps the CLR type of this instance. (Inherited from DependencyObject.)

System_CAPS_pubpropertyDispatcher

Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)

System_CAPS_pubpropertyGesture

Gets or sets the InputGesture associated with this input binding.

System_CAPS_pubpropertyIsFrozen

Gets a value that indicates whether the object is currently modifiable. (Inherited from Freezable.)

System_CAPS_pubpropertyIsSealed

Gets a value that indicates whether this instance is currently sealed (read-only).(Inherited from DependencyObject.)

NameDescription
System_CAPS_pubmethodCheckAccess()

Determines whether the calling thread has access to this DispatcherObject.(Inherited from DispatcherObject.)

System_CAPS_pubmethodClearValue(DependencyProperty)

Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.)

System_CAPS_pubmethodClearValue(DependencyPropertyKey)

Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.)

System_CAPS_pubmethodClone()

Creates a modifiable clone of the Freezable, making deep copies of the object's values. When copying the object's dependency properties, this method copies expressions (which might no longer resolve) but not animations or their current values. (Inherited from Freezable.)

System_CAPS_protmethodCloneCore(Freezable)

Copies the base (non-animated) values of the properties of the specified object.(Overrides Freezable.CloneCore(Freezable).)

System_CAPS_pubmethodCloneCurrentValue()

Creates a modifiable clone (deep copy) of the Freezable using its current values.(Inherited from Freezable.)

System_CAPS_protmethodCloneCurrentValueCore(Freezable)

Copies the current values of the properties of the specified object.(Overrides Freezable.CloneCurrentValueCore(Freezable).)

System_CAPS_pubmethodCoerceValue(DependencyProperty)

Coerces the value of the specified dependency property. This is accomplished by invoking any CoerceValueCallback function specified in property metadata for the dependency property as it exists on the calling DependencyObject.(Inherited from DependencyObject.)

System_CAPS_protmethodCreateInstance()

Initializes a new instance of the Freezable class. (Inherited from Freezable.)

System_CAPS_protmethodCreateInstanceCore()

Creates an instance of an InputBinding.(Overrides Freezable.CreateInstanceCore().)

System_CAPS_pubmethodEquals(Object)

Determines whether a provided DependencyObject is equivalent to the current DependencyObject.(Inherited from DependencyObject.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodFreeze()

Makes the current object unmodifiable and sets its IsFrozen property to true. (Inherited from Freezable.)

System_CAPS_protmethodFreezeCore(Boolean)

Makes the Freezable object unmodifiable or tests whether it can be made unmodifiable.(Inherited from Freezable.)

System_CAPS_pubmethodGetAsFrozen()

Creates a frozen copy of the Freezable, using base (non-animated) property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.)

System_CAPS_protmethodGetAsFrozenCore(Freezable)

Makes the instance a frozen clone of the specified Freezable by using base (non-animated) property values.(Overrides Freezable.GetAsFrozenCore(Freezable).)

System_CAPS_pubmethodGetCurrentValueAsFrozen()

Creates a frozen copy of the Freezable using current property values. Because the copy is frozen, any frozen sub-objects are copied by reference.(Inherited from Freezable.)

System_CAPS_protmethodGetCurrentValueAsFrozenCore(Freezable)

Makes the current instance a frozen clone of the specified Freezable. If the object has animated dependency properties, their current animated values are copied.(Overrides Freezable.GetCurrentValueAsFrozenCore(Freezable).)

System_CAPS_pubmethodGetHashCode()

Gets a hash code for this DependencyObject.(Inherited from DependencyObject.)

System_CAPS_pubmethodGetLocalValueEnumerator()

Creates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodGetValue(DependencyProperty)

Returns the current effective value of a dependency property on this instance of a DependencyObject. (Inherited from DependencyObject.)

System_CAPS_pubmethodInvalidateProperty(DependencyProperty)

Re-evaluates the effective value for the specified dependency property(Inherited from DependencyObject.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_protmethodOnChanged()

Called when the current Freezable object is modified. (Inherited from Freezable.)

System_CAPS_protmethodOnFreezablePropertyChanged(DependencyObject, DependencyObject)

Ensures that appropriate context pointers are established for a DependencyObjectType data member that has just been set.(Inherited from Freezable.)

System_CAPS_protmethodOnFreezablePropertyChanged(DependencyObject, DependencyObject, DependencyProperty)

This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code.(Inherited from Freezable.)

System_CAPS_protmethodOnPropertyChanged(DependencyPropertyChangedEventArgs)

Overrides the DependencyObject implementation of OnPropertyChanged to also invoke any Changed handlers in response to a changing dependency property of type Freezable.(Inherited from Freezable.)

System_CAPS_pubmethodReadLocalValue(DependencyProperty)

Returns the local value of a dependency property, if it exists. (Inherited from DependencyObject.)

System_CAPS_protmethodReadPreamble()

Ensures that the Freezable is being accessed from a valid thread. Inheritors of Freezable must call this method at the beginning of any API that reads data members that are not dependency properties.(Inherited from Freezable.)

System_CAPS_pubmethodSetCurrentValue(DependencyProperty, Object)

Sets the value of a dependency property without changing its value source. (Inherited from DependencyObject.)

System_CAPS_pubmethodSetValue(DependencyProperty, Object)

Sets the local value of a dependency property, specified by its dependency property identifier. (Inherited from DependencyObject.)

System_CAPS_pubmethodSetValue(DependencyPropertyKey, Object)

Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.)

System_CAPS_protmethodShouldSerializeProperty(DependencyProperty)

Returns a value that indicates whether serialization processes should serialize the value for the provided dependency property.(Inherited from DependencyObject.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethodVerifyAccess()

Enforces that the calling thread has access to this DispatcherObject.(Inherited from DispatcherObject.)

System_CAPS_protmethodWritePostscript()

Raises the Changed event for the Freezable and invokes its OnChanged method. Classes that derive from Freezable should call this method at the end of any API that modifies class members that are not stored as dependency properties.(Inherited from Freezable.)

System_CAPS_protmethodWritePreamble()

Verifies that the Freezable is not frozen and that it is being accessed from a valid threading context. Freezable inheritors should call this method at the beginning of any API that writes to data members that are not dependency properties. (Inherited from Freezable.)

NameDescription
System_CAPS_pubfieldSystem_CAPS_staticCommandParameterProperty

Identifies the CommandParameter dependency property.

System_CAPS_pubfieldSystem_CAPS_staticCommandProperty

Identifies the Command dependency property.

System_CAPS_pubfieldSystem_CAPS_staticCommandTargetProperty

Identifies the CommandTarget dependency property.

NameDescription
System_CAPS_pubeventChanged

Occurs when the Freezable or an object it contains is modified. (Inherited from Freezable.)

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.

<inputBindingDerivedClass…/>

inputBindingDerivedClass

A derived class of InputBinding that supports object element syntax, such as KeyBinding or MouseBinding. See Remarks.

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:

  • Clicking a button.

  • Pressing CTRL+C.

  • Right-clicking a StackPanel (outside the ListBox).

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

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

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 CommandParameter property is bound to the selected item in the ListBox, and the Command property is bound to 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>

.NET Framework
Available since 3.0

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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