DrawingVisual Constructor

Definition

Initializes a new instance of the DrawingVisual class.

public DrawingVisual ();

Examples

In the following example, a DrawingVisual object is created, and a rectangle is drawn into its drawing context. Notice that you must call the Close method of the DrawingContext to persist drawing content.

// 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;
}

Remarks

When you create a DrawingVisual object, it has no drawing content. You can add text, graphic, or image content by retrieving the drawing context of the object and drawing into it. A drawing context is returned by calling the RenderOpen method of a DrawingVisual object.

Applies to

Prodotto Versioni
.NET Framework 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9