InkOverlay.CursorDown 事件

当光标尖与数字化 Tablet 表面接触时发生。

命名空间:  Microsoft.Ink
程序集:  Microsoft.Ink(在 Microsoft.Ink.dll 中)

语法

声明
Public Event CursorDown As InkCollectorCursorDownEventHandler
用法
Dim instance As InkOverlay
Dim handler As InkCollectorCursorDownEventHandler

AddHandler instance.CursorDown, handler
public event InkCollectorCursorDownEventHandler CursorDown
public:
 event InkCollectorCursorDownEventHandler^ CursorDown {
    void add (InkCollectorCursorDownEventHandler^ value);
    void remove (InkCollectorCursorDownEventHandler^ value);
}
/** @event */
public void add_CursorDown (InkCollectorCursorDownEventHandler value)
/** @event */
public void remove_CursorDown (InkCollectorCursorDownEventHandler value)
JScript 不支持事件。

备注

事件处理程序接收 InkCollectorCursorDownEventArgs 类型的参数,该参数包含有关此事件的数据。

创建 InkCollectorCursorDownEventHandler 委托时,需要标识将处理该事件的方法。若要将该事件与事件处理程序关联,请将该委托的一个实例添加到事件中。除非移除了该委托,否则每当发生该事件时就会调用此事件处理程序。出于性能方面的原因,默认事件关注处于关闭状态,但如果添加事件处理程序,它将自动打开。

如果在事件处理程序中执行太多代码,则此事件可能对墨迹 性能产生不利影响。若要提高实时墨迹性能,请在墨迹书写时隐藏鼠标光标。为此,请在 MouseDown 事件处理程序中隐藏鼠标光标,并在 MouseUp 事件处理程序中显示鼠标光标。

示例

此示例演示如何订阅 CursorDown 事件和 Stroke 事件来计算用户创建笔画所用的时间长度。

在笔画开始时,会激发 CursorDown 事件。当前时间会放置在 Stroke 对象的 ExtendedProperties 集合中。

Private Sub mInkObject_CursorDown(ByVal sender As Object, ByVal e As InkCollectorCursorDownEventArgs)
    ' add extended property indicating the time the stroke started
    ' STROKE_START_GUID is class level string via GUID generator
    e.Stroke.ExtendedProperties.Add(New Guid(STROKE_START_GUID), DateTime.Now)
End Sub
private void mInkObject_CursorDown(object sender, InkCollectorCursorDownEventArgs e)
{
    // add extended property indicating the time the stroke started
    // STROKE_START_GUID is class level string via GUID generator
    e.Stroke.ExtendedProperties.Add(new Guid(STROKE_START_GUID), DateTime.Now);
}

笔画完成时,会激发 Stroke 事件。起始时间是从 Stroke 对象的 ExtendedProperties 集合中获取的,可用于计算所用的时间。

Private Sub mInkObject_Stroke1(ByVal sender As Object, ByVal e As InkCollectorStrokeEventArgs)
    ' check to see if extended property for start time exists
    ' Attempting to access an extended property that hasn't been created throws an exception
    ' STROKE_START_GUID is class level string via GUID generator
    If (e.Stroke.ExtendedProperties.DoesPropertyExist(New Guid(STROKE_START_GUID))) Then

        Dim startTime As DateTime = DirectCast(e.Stroke.ExtendedProperties(New Guid(STROKE_START_GUID)).Data, DateTime)
        Dim endTime As DateTime = DateTime.Now
        Dim span As TimeSpan = New TimeSpan(endTime.Ticks - startTime.Ticks)

        ' add extended property indicating the time the stroke ended
        ' STROKE_END_GUID is class level string via GUID generator
        e.Stroke.ExtendedProperties.Add(New Guid(STROKE_END_GUID), endTime)

        ' display the number of seconds in creating this stroke
        Me.statusLabelStrokeTime.Text = span.TotalSeconds.ToString()
    End If
End Sub
private void mInkObject_Stroke1(object sender, InkCollectorStrokeEventArgs e)
{
    // check to see if extended property for start time exists
    // Attempting to access an extended property that hasn't been created throws an exception
    // STROKE_START_GUID is class level string via GUID generator
    if (e.Stroke.ExtendedProperties.DoesPropertyExist(new Guid(STROKE_START_GUID)))
    {
        DateTime startTime = (DateTime)e.Stroke.ExtendedProperties[new Guid(STROKE_START_GUID)].Data;
        DateTime endTime = DateTime.Now;
        TimeSpan span = new TimeSpan(endTime.Ticks - startTime.Ticks);

        // add extended property indicating the time the stroke ended
        // STROKE_END_GUID is class level string via GUID generator
        e.Stroke.ExtendedProperties.Add(new Guid(STROKE_END_GUID), endTime);

        // display the number of seconds in creating this stroke
        this.statusLabelStrokeTime.Text = span.TotalSeconds.ToString();
    }
}

平台

Windows Vista

.NET Framework 和 .NET Compact Framework 并不是对每个平台的所有版本都提供支持。有关支持的版本的列表,请参见.NET Framework 系统要求

版本信息

.NET Framework

受以下版本支持:3.0

另请参见

参考

InkOverlay 类

InkOverlay 成员

Microsoft.Ink 命名空间

Cursor

CursorButton

InkCollectorCursorDownEventArgs

InkOverlay.CursorButtonUp

InkOverlay.CursorDown