InkCanvas.HitTestSelection(Point) 方法

定义

命名空间:

System.Windows.Controls

程序集:

PresentationFramework.dll

返回一个值，该值指示选择装饰器的哪个部分与指定点相交或包围指定点。

public:
 System::Windows::Controls::InkCanvasSelectionHitResult HitTestSelection(System::Windows::Point point);

public System.Windows.Controls.InkCanvasSelectionHitResult HitTestSelection (System.Windows.Point point);

member this.HitTestSelection : System.Windows.Point -> System.Windows.Controls.InkCanvasSelectionHitResult

Public Function HitTestSelection (point As Point) As InkCanvasSelectionHitResult

参数

point

Point

要进行命中测试的点。

返回

InkCanvasSelectionHitResult

一个值，该值指示选择装饰器的哪个部分与指定点相交或包围指定点。

示例

以下示例演示如何用于 HitTestSelection 确定是否创建用于启动拖放的 ASA DataObject 。 若要在两个 InkCanvas 对象之间实现拖放，请参阅 操作方法：拖放墨迹。

void InkCanvas_PreviewMouseDown(object sender, MouseEventArgs e)
{
    InkCanvas ic = (InkCanvas)sender;
    
    Point pt = e.GetPosition(ic);

    // If the user is moving selected strokes, prepare the strokes to be
    // moved to another InkCanvas.
    if (ic.HitTestSelection(pt) == 
        InkCanvasSelectionHitResult.Selection)
    {
        StrokeCollection selectedStrokes = ic.GetSelectedStrokes();
        StrokeCollection strokesToMove = selectedStrokes.Clone();
    
        // Remove the offset of the selected strokes so they
        // are positioned when the strokes are dropped.
        Rect inkBounds = strokesToMove.GetBounds();
        TranslateStrokes(strokesToMove, -inkBounds.X, -inkBounds.Y);
        
        // Perform drag and drop.
        MemoryStream ms = new MemoryStream();
        strokesToMove.Save(ms);
        DataObject dataObject = new DataObject(
            StrokeCollection.InkSerializedFormat, ms);
        
        DragDropEffects effects = 
            DragDrop.DoDragDrop(ic, dataObject, 
                                DragDropEffects.Move);

        if ((effects & DragDropEffects.Move) == 
             DragDropEffects.Move)
        {
            // Remove the selected strokes 
            // from the current InkCanvas.
            ic.Strokes.Remove(selectedStrokes);
        }
    }
}

Private Sub InkCanvas_PreviewMouseDown(ByVal sender As Object, _
                               ByVal e As MouseButtonEventArgs)

    Dim ic As InkCanvas = CType(sender, InkCanvas)

    Dim pt As Point = e.GetPosition(ic)

    ' If the user is moving selected strokes, prepare the strokes to be
    ' moved to another InkCanvas.
    If ic.HitTestSelection(pt) = InkCanvasSelectionHitResult.Selection Then

        Dim selectedStrokes As StrokeCollection = _
                               ic.GetSelectedStrokes()

        Dim strokesToMove As StrokeCollection = _
                             selectedStrokes.Clone()

        ' Remove the offset of the selected strokes so they
        ' are positioned when the strokes are dropped.
        Dim inkBounds As Rect = strokesToMove.GetBounds()
        TranslateStrokes(strokesToMove, -inkBounds.X, -inkBounds.Y)

        ' Perform drag and drop.
        Dim ms As New MemoryStream()
        strokesToMove.Save(ms)

        Dim dataObject As New DataObject _
            (StrokeCollection.InkSerializedFormat, ms)

        Dim effects As DragDropEffects = _
            DragDrop.DoDragDrop(ic, dataObject, DragDropEffects.Move)

        If (effects And DragDropEffects.Move) = DragDropEffects.Move Then

            ' Remove the selected strokes from the current InkCanvas.
            ic.Strokes.Remove(selectedStrokes)
        End If
    End If

End Sub

注解

HitTestSelection使用该方法确定点是位于笔划选择边界内还是位于八个控点之一。 执行拖放操作时，这非常有用。