InkCanvas.HitTestSelection(Point) 方法

定義

命名空間:

System.Windows.Controls

組件:

PresentationFramework.dll

傳回值，這個表示選取範圍裝飾項的哪一個部分會穿過或圍繞所指定的點。

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

參數

point

Point

要進行點擊測試的點。

傳回

InkCanvasSelectionHitResult

表示選取範圍裝飾項的哪一個部分會穿過或圍繞所指定之點的值。

範例

下列範例示範如何使用 HitTestSelection 來判斷是否要建立 DataObject 來起始拖放。 若要在兩個 InkCanvas 物件之間實作拖放，請參閱 如何：拖放筆跡。

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

備註

HitTestSelection使用 方法來判中斷點是在筆劃選取範圍的界限內，還是位於八個控點的其中一個。 執行拖放作業時，這非常有用。