DrawingVisual 建構函式

public:
 DrawingVisual();

public DrawingVisual();

Public Sub New ()

範例

在以下範例中，建立一個 DrawingVisual 物件，並將一個矩形繪製到其繪圖上下文中。 請注意，你必須呼叫 Close 該方法 DrawingContext 來持續繪製內容。

// Create a DrawingVisual that contains a rectangle.
private DrawingVisual CreateDrawingVisualRectangle()
{
    DrawingVisual drawingVisual = new DrawingVisual();

    // Retrieve the DrawingContext in order to create new drawing content.
    DrawingContext drawingContext = drawingVisual.RenderOpen();

    // Create a rectangle and draw it in the DrawingContext.
    Rect rect = new Rect(new System.Windows.Point(160, 100), new System.Windows.Size(320, 80));
    drawingContext.DrawRectangle(System.Windows.Media.Brushes.LightBlue, (System.Windows.Media.Pen)null, rect);

    // Persist the drawing content.
    drawingContext.Close();

    return drawingVisual;
}

' Create a DrawingVisual that contains a rectangle.
Private Function CreateDrawingVisualRectangle() As DrawingVisual
    Dim drawingVisual As New DrawingVisual()

    ' Retrieve the DrawingContext in order to create new drawing content.
    Dim drawingContext As DrawingContext = drawingVisual.RenderOpen()

    ' Create a rectangle and draw it in the DrawingContext.
    Dim rect As New Rect(New Point(160, 100), New Size(320, 80))
    drawingContext.DrawRectangle(Brushes.LightBlue, CType(Nothing, Pen), rect)

    ' Persist the drawing content.
    drawingContext.Close()

    Return drawingVisual
End Function

備註

當您創建一個DrawingVisual物件時，它沒有任何繪圖內容。 你可以透過取得物件的繪圖上下文並向其繪製，來添加文字、圖像或圖片內容。 透過呼叫 RenderOpen 物件的方法 DrawingVisual 來回傳繪圖上下文。