TouchDevice Class

 

Represents a single touch input produced by a finger on a touchscreen.

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


[UIPermissionAttribute(SecurityAction::InheritanceDemand, Unrestricted = true)]
public ref class TouchDevice abstract : InputDevice, IManipulator

NameDescription
System_CAPS_protmethodTouchDevice(Int32)

Called from constructors in derived classes to initialize the TouchDevice class.

NameDescription
System_CAPS_pubpropertyActiveSource

Gets the PresentationSource that is reporting input for this device.(Overrides InputDevice::ActiveSource.)

System_CAPS_pubpropertyCaptured

Gets the element that captured the TouchDevice.

System_CAPS_pubpropertyCaptureMode

Gets the capture policy of the TouchDevice.

System_CAPS_pubpropertyDirectlyOver

Gets the element that the touch contact point is directly over.

System_CAPS_pubpropertyDispatcher

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

System_CAPS_pubpropertyId

Gets the unique identifier of the TouchDevice, as provided by the operating system.

System_CAPS_pubpropertyIsActive

Gets a value that indicates whether the device is active.

System_CAPS_pubpropertyTarget

Gets the element that receives input from the TouchDevice.(Overrides InputDevice::Target.)

NameDescription
System_CAPS_protmethodActivate()

Adds the TouchDevice to the input messaging system.

System_CAPS_pubmethodCapture(IInputElement^)

Captures a touch to the specified element by using the Element capture mode.

System_CAPS_pubmethodCapture(IInputElement^, CaptureMode)

Captures a touch to the specified element by using the specified CaptureMode.

System_CAPS_pubmethodCheckAccess()

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

System_CAPS_protmethodDeactivate()

Removes the TouchDevice from the input messaging system.

System_CAPS_pubmethodEquals(Object^)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

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_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetIntermediateTouchPoints(IInputElement^)

When overridden in a derived class, returns all touch points that are collected between the most recent and previous touch events.

System_CAPS_pubmethodGetTouchPoint(IInputElement^)

Returns the current position of the touch device relative to the specified element.

System_CAPS_pubmethodGetType()

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

System_CAPS_protmethodMemberwiseClone()

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

System_CAPS_protmethodOnCapture(IInputElement^, CaptureMode)

Called when a touch is captured to an element.

System_CAPS_protmethodOnManipulationEnded(Boolean)

Called when a manipulation has ended.

System_CAPS_protmethodOnManipulationStarted()

Called when a manipulation is started.

System_CAPS_protmethodReportDown()

Reports that a touch is pressed on an element.

System_CAPS_protmethodReportMove()

Reports that a touch is moving across an element.

System_CAPS_protmethodReportUp()

Reports that a touch was lifted from an element.

System_CAPS_protmethodSetActiveSource(PresentationSource^)

Sets the PresentationSource that is reporting input for this device.

System_CAPS_pubmethodSynchronize()

Forces the TouchDevice to synchronize the user interface with underlying touch points.

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.)

NameDescription
System_CAPS_pubeventActivated

Occurs when the TouchDevice is added to the input messaging system.

System_CAPS_pubeventDeactivated

Occurs when the TouchDevice is removed from the input messaging system.

System_CAPS_pubeventUpdated

Occurs when a touch message is sent.

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethodIManipulator::GetPosition(IInputElement^)

Returns the position of the IManipulator object.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIManipulator::ManipulationEnded(Boolean)

Occurs when a manipulation has ended.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIManipulator::Id

Gets the unique identifier of the TouchDevice as provided by the operating system.

You typically access a TouchDevice by using the TouchEventArgs::TouchDevice property. A TouchDevice represents a single touch on a screen. If multiple touches are present, use the Id property to distinguish between them.

System_CAPS_noteNote

This class contains an inheritance demand at the class level that applies to all members. A SecurityException is thrown when the derived class does not have full-trust permission. For more information about security demands, see Link Demands and Inheritance Demands.

The following example enables you to create simple patterns on a Canvas by dragging two fingers on a touchscreen. Each touch is represented by a TouchDevice in the TouchEventArgs. The pattern is created by drawing a line between the touch points that are provided by the touches. This example requires a Windows Touch–compatible screen.

The following markup creates the user interface, which consists of a Canvas that is centered in a grid, and attaches the event handlers for the touch events.

<Window x:Class="WpfTouchEventsSample.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="525" Width="525">
    <Grid>
        <Canvas x:Name="canvas1"
                Width="500" Height="500"
                Background="Black"
                TouchDown="canvas_TouchDown"
                TouchMove="canvas_TouchMove"
                TouchUp="canvas_TouchUp" />
    </Grid>
</Window>

The following code handles the touch events. When a touch is pressed on the Canvas, the TouchDevice is captured to the Canvas. When the touch is lifted, the TouchDevice is released. When a touch moves on the Canvas, the Id is checked. If the move came from the first touch, its location is recorded. If the move came from the second touch, a line is drawn from the position of the first touch to the position of the second touch.

No code example is currently available or this language may not be supported.

UIPermission

for deriving from this class. Security action: InheritanceDemand. Associated enumeration: PermissionState::Unrestricted

.NET Framework
Available since 4.0
Silverlight
Available since 3.0
Windows Phone Silverlight
Available since 7.0

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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