StylusPlugIn 类

参考

定义

命名空间:: System.Windows.Input.StylusPlugIns

程序集:: PresentationCore.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

表示可添加到控件的 StylusPlugIns 属性中的插件。

public ref class StylusPlugIn abstract

public abstract class StylusPlugIn

type StylusPlugIn = class

Public MustInherit Class StylusPlugIn

继承: Object
StylusPlugIn

派生: System.Windows.Input.StylusPlugIns.DynamicRenderer

示例

以下示例创建一个自定义，该自定义 StylusPlugIn 将墨迹限制为控件上的特定区域。

// EventArgs for the StrokeRendered event.
public class StrokeRenderedEventArgs : EventArgs
{
    StylusPointCollection strokePoints;

    public StrokeRenderedEventArgs(StylusPointCollection points)
    {
        strokePoints = points;
    }

    public StylusPointCollection StrokePoints
    {
        get
        {
            return strokePoints;
        }
    }
}

// EventHandler for the StrokeRendered event.
public delegate void StrokeRenderedEventHandler(object sender, StrokeRenderedEventArgs e);

// A StylusPlugin that restricts the input area
class FilterPlugin : StylusPlugIn
{
    StylusPointCollection collectedPoints;
    int currentStylus = -1;
    public event StrokeRenderedEventHandler StrokeRendered;

    protected override void OnStylusDown(RawStylusInput rawStylusInput)
    {
        // Run the base class before modifying the data
        base.OnStylusDown(rawStylusInput);

        if (currentStylus == -1)
        {
            StylusPointCollection pointsFromEvent = rawStylusInput.GetStylusPoints();

            // Create an emtpy StylusPointCollection to contain the filtered
            // points.
            collectedPoints = new StylusPointCollection(pointsFromEvent.Description);
            
            // Restrict the stylus input and add the filtered 
            // points to collectedPoints. 
            StylusPointCollection points = FilterPackets(pointsFromEvent);
            rawStylusInput.SetStylusPoints(points);
            collectedPoints.Add(points);

            currentStylus = rawStylusInput.StylusDeviceId;
        }
    }

    protected override void OnStylusMove(RawStylusInput rawStylusInput)
    {
        // Run the base class before modifying the data
        base.OnStylusMove(rawStylusInput);

        if (currentStylus == rawStylusInput.StylusDeviceId)
        {
            StylusPointCollection pointsFromEvent = rawStylusInput.GetStylusPoints();

            // Restrict the stylus input and add the filtered 
            // points to collectedPoints. 
            StylusPointCollection points = FilterPackets(pointsFromEvent);
            rawStylusInput.SetStylusPoints(points);
            collectedPoints.Add(points);
        }
    }

    protected override void OnStylusUp(RawStylusInput rawStylusInput)
    {
        // Run the base class before modifying the data
        base.OnStylusUp(rawStylusInput);

        if (currentStylus == rawStylusInput.StylusDeviceId)
        {
            StylusPointCollection pointsFromEvent = rawStylusInput.GetStylusPoints();

            // Restrict the stylus input and add the filtered 
            // points to collectedPoints. 
            StylusPointCollection points = FilterPackets(pointsFromEvent);
            rawStylusInput.SetStylusPoints(points);
            collectedPoints.Add(points);

            // Subscribe to the OnStylusUpProcessed method.
            rawStylusInput.NotifyWhenProcessed(collectedPoints);

            currentStylus = -1;
        }
    }

    private StylusPointCollection FilterPackets(StylusPointCollection stylusPoints)
    {
        // Modify the (X,Y) data to move the points 
        // inside the acceptable input area, if necessary
        for (int i = 0; i < stylusPoints.Count; i++)
        {
            StylusPoint sp = stylusPoints[i];
            if (sp.X < 50) sp.X = 50;
            if (sp.X > 250) sp.X = 250;
            if (sp.Y < 50) sp.Y = 50;
            if (sp.Y > 250) sp.Y = 250;
            stylusPoints[i] = sp;
        }

        // Return the modified StylusPoints.
        return stylusPoints;
    }

    // This is called on the application thread.  
    protected override void OnStylusUpProcessed(object callbackData, bool targetVerified)
    {
        // Check that the element actually receive the OnStylusUp input.
        if (targetVerified)
        {
            StylusPointCollection strokePoints = callbackData as StylusPointCollection;

            if (strokePoints == null)
            {
                return;
            }

            // Raise the StrokeRendered event so the consumer of the plugin can
            // add the filtered stroke to its StrokeCollection.
            StrokeRenderedEventArgs e = new StrokeRenderedEventArgs(strokePoints);
            OnStrokeRendered(e);
        }
    }

    protected virtual void OnStrokeRendered(StrokeRenderedEventArgs e)
    {
        if (StrokeRendered != null)
        {
            StrokeRendered(this, e);
        }
    }
}

' EventArgs for the StrokeRendered event.
Public Class StrokeRenderedEventArgs
    Inherits EventArgs

    Private currentStrokePoints As StylusPointCollection

    Public Sub New(ByVal points As StylusPointCollection)

        currentStrokePoints = points

    End Sub


    Public ReadOnly Property StrokePoints() As StylusPointCollection
        Get
            Return currentStrokePoints
        End Get
    End Property
End Class

' EventHandler for the StrokeRendered event.
Public Delegate Sub StrokeRenderedEventHandler(ByVal sender As Object, ByVal e As StrokeRenderedEventArgs) 


' A StylusPlugin that restricts the input area
Class FilterPlugin
    Inherits StylusPlugIn

    Private collectedPoints As StylusPointCollection
    Private currentStylus As Integer = -1
    Public Event StrokeRendered As StrokeRenderedEventHandler


    Protected Overrides Sub OnStylusDown(ByVal rawStylusInput As RawStylusInput)

        ' Run the base class before we modify the data
        MyBase.OnStylusDown(rawStylusInput)

        If currentStylus = -1 Then

            Dim pointsFromEvent As StylusPointCollection = rawStylusInput.GetStylusPoints()

            ' Create an emtpy StylusPointCollection to contain the filtered
            ' points.
            collectedPoints = New StylusPointCollection(pointsFromEvent.Description)

            ' Restrict the stylus input and add the filtered 
            ' points to collectedPoints. 
            Dim points As StylusPointCollection = FilterPackets(pointsFromEvent)
            rawStylusInput.SetStylusPoints(points)
            collectedPoints.Add(points)

            currentStylus = rawStylusInput.StylusDeviceId

        End If

    End Sub


    Protected Overrides Sub OnStylusMove(ByVal rawStylusInput As RawStylusInput)

        ' Run the base class before we modify the data
        MyBase.OnStylusMove(rawStylusInput)

        If currentStylus = rawStylusInput.StylusDeviceId Then

            Dim pointsFromEvent As StylusPointCollection = rawStylusInput.GetStylusPoints()

            ' Restrict the stylus input and add the filtered 
            ' points to collectedPoints. 
            Dim points As StylusPointCollection = FilterPackets(pointsFromEvent)
            rawStylusInput.SetStylusPoints(points)
            collectedPoints.Add(points)

        End If

    End Sub

    Protected Overrides Sub OnStylusUp(ByVal rawStylusInput As RawStylusInput)

        ' Run the base class before we modify the data
        MyBase.OnStylusUp(rawStylusInput)

        If currentStylus = rawStylusInput.StylusDeviceId Then

            Dim pointsFromEvent As StylusPointCollection = rawStylusInput.GetStylusPoints()

            ' Restrict the stylus input and add the filtered 
            ' points to collectedPoints. 
            Dim points As StylusPointCollection = FilterPackets(pointsFromEvent)
            rawStylusInput.SetStylusPoints(points)
            collectedPoints.Add(points)

            RecordPoints(collectedPoints, "collectPoints - StylusUp")
            ' Subscribe to the OnStylusUpProcessed method.
            rawStylusInput.NotifyWhenProcessed(collectedPoints)

            currentStylus = -1

        End If

    End Sub


    Private Function FilterPackets(ByVal stylusPoints As StylusPointCollection) As StylusPointCollection

        ' Modify the (X,Y) data to move the points 
        ' inside the acceptable input area, if necessary.
        Dim i As Integer

        For i = 0 To stylusPoints.Count - 1

            Dim sp As StylusPoint = stylusPoints(i)

            If sp.X < 50 Then
                sp.X = 50
            End If

            If sp.X > 250 Then
                sp.X = 250
            End If

            If sp.Y < 50 Then
                sp.Y = 50
            End If

            If sp.Y > 250 Then
                sp.Y = 250
            End If

            stylusPoints(i) = sp

        Next i

        ' Return the modified StylusPoints.
        Return stylusPoints

    End Function 'FilterPackets

    ' This is called on the application thread.
    Protected Overrides Sub OnStylusUpProcessed(ByVal callbackData As Object, _
                                                ByVal targetVerified As Boolean)

        ' Check that the element actually receive the OnStylusUp input.
        If targetVerified Then
            Dim strokePoints As StylusPointCollection

            strokePoints = CType(callbackData, StylusPointCollection)

            If strokePoints Is Nothing Then
                Return
            End If

            ' Raise the StrokeRendered event so the consumer of the plugin can
            ' add the filtered stroke to its StrokeCollection.
            RecordPoints(strokePoints, "onStylusUpProcessed")
            Dim e As New StrokeRenderedEventArgs(strokePoints)
            OnStrokeRendered(e)
        End If

    End Sub


    Protected Overridable Sub OnStrokeRendered(ByVal e As StrokeRenderedEventArgs)

        RaiseEvent StrokeRendered(Me, e)

    End Sub

    Public Sub RecordPoints(ByVal points As StylusPointCollection, ByVal name As String)

        System.Diagnostics.Debug.WriteLine(name)
        For Each point As StylusPoint In points
            System.Diagnostics.Debug.WriteLine("   x: " & point.X & " y: " & point.Y)
        Next
    End Sub
End Class

注解

这样 StylusPlugIn ，就可以在单独的线程上操作 StylusPoint 对象。使用单独的线程，以便即使应用程序执行其他操作，墨迹仍呈现为平板电脑笔输入数据。

若要截获硬件中的触笔点，请创建继承自该类的 StylusPlugIn 类。该 StylusPlugIn 类具有以下方法，你可以替代这些方法以操作 StylusPoint 笔线程池中的线程上的对象。

笔的输入将路由到笔线程上的元素 StylusPlugIn 。由于无法对笔线程执行准确的命中测试，因此某些元素偶尔可能会接收用于其他元素的触笔输入。如果需要确保在执行操作之前正确路由输入，请在或OnStylusMoveProcessed OnStylusUpProcessed方法中OnStylusDownProcessed订阅和执行操作。执行准确的命中测试后，主应用程序线程会调用这些方法。若要订阅这些方法，请调用 NotifyWhenProcessed 在笔线程上发生的方法中的方法。例如，如果调用 NotifyWhenProcessed ， OnStylusMove则 OnStylusMoveProcessed 会发生。

备注

如果使用 StylusPlugIn 控件内部，则应广泛测试插件和控制，以确保它们不会引发任何意外异常。

XAML 文本用法

此类通常不用于 XAML。

构造函数

StylusPlugIn()

初始化 StylusPlugIn 类的新实例。

属性

Element	获取向其附加 UIElement 的 StylusPlugIn。
ElementBounds	获取元素的缓存边界。
Enabled	获取或设置 StylusPlugIn 是否处于活动状态。
IsActiveForInput	获取 StylusPlugIn 是否可以接受输入。

方法

Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
OnAdded()	在将 StylusPlugIn 添加到元素中时发生。
OnEnabledChanged()	当 Enabled 属性更改时发生。
OnIsActiveForInputChanged()	当 IsActiveForInput 属性更改时发生。
OnRemoved()	在从元素中移除 StylusPlugIn 时发生。
OnStylusDown(RawStylusInput)	当触笔接触数字化仪时，在笔线程池中的线程上发生。
OnStylusDownProcessed(Object, Boolean)	当触笔接触数字化仪时，在应用程序 UI（用户界面）线程上发生。
OnStylusEnter(RawStylusInput, Boolean)	当光标进入元素的边界时在笔线程上发生。
OnStylusLeave(RawStylusInput, Boolean)	当光标离开元素的边界时在笔线程上发生。
OnStylusMove(RawStylusInput)	当触笔移到数字化仪上时，在笔线程上发生。
OnStylusMoveProcessed(Object, Boolean)	当触笔移到数字化仪上时，在应用程序 UI（用户界面）线程上发生。
OnStylusUp(RawStylusInput)	当用户将触笔从数字化仪上提起时，在笔线程上发生。
OnStylusUpProcessed(Object, Boolean)	当用户将触笔从数字化仪上提起时，在应用程序 UI（用户界面）线程上发生。
ToString()	返回表示当前对象的字符串。 (继承自 Object)

适用于

通过

StylusPlugIn 类

定义

示例

注解

XAML 文本用法

构造函数

属性

方法

适用于

其他资源