DrawingVisual.RenderOpen DrawingVisual.RenderOpen DrawingVisual.RenderOpen DrawingVisual.RenderOpen Method

Definición

Abre el objeto DrawingVisual para su representación.Opens the DrawingVisual object for rendering. El valor de DrawingContext devuelto se puede utilizar para representar en DrawingVisual.The returned DrawingContext value can be used to render into the DrawingVisual.

public:
 System::Windows::Media::DrawingContext ^ RenderOpen();
public System.Windows.Media.DrawingContext RenderOpen ();
member this.RenderOpen : unit -> System.Windows.Media.DrawingContext
Public Function RenderOpen () As DrawingContext

Devoluciones

Ejemplos

En el ejemplo siguiente, se DrawingVisual crea un objeto y se devuelve DrawingContext su.In the following example, a DrawingVisual object is created, and its DrawingContext returned.

// 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

El orden en el que se dibuja en el contexto de dibujo es importante: cada dibujo subsiguiente se dibuja encima de los demás.The order in which you draw into the drawing context is important - each succeeding drawing is drawn on top of the others. En el ejemplo siguiente, el rectángulo se dibuja primero y después el texto.In the following example, the rectangle is drawn first, then the text.

// Retrieve the DrawingContext in order to draw into the visual object.
DrawingContext drawingContext = drawingVisual.RenderOpen();

// Draw a rectangle into the DrawingContext.
Rect rect = new Rect(new Point(160, 100), new Size(320, 80));
drawingContext.DrawRectangle(Brushes.LightBlue, (Pen)null, rect);

// Draw a formatted text string into the DrawingContext.
drawingContext.DrawText(
   new FormattedText("Hello, world",
      CultureInfo.GetCultureInfo("en-us"),
      FlowDirection.LeftToRight,
      new Typeface("Verdana"),
      36, Brushes.Black),
      new Point(200, 116));

// Persist the drawing content.
drawingContext.Close();
' Retrieve the DrawingContext in order to draw into the visual object.
Dim drawingContext As DrawingContext = drawingVisual.RenderOpen()

' Draw a rectangle into the DrawingContext.
Dim rect As New Rect(New Point(160, 100), New Size(320, 80))
drawingContext.DrawRectangle(Brushes.LightBlue, CType(Nothing, Pen), rect)

' Draw a formatted text string into the DrawingContext.
drawingContext.DrawText(New FormattedText("Hello, world", CultureInfo.GetCultureInfo("en-us"), FlowDirection.LeftToRight, New Typeface("Verdana"), 36, Brushes.Black), New Point(200, 116))

' Persist the drawing content.
drawingContext.Close()

Comentarios

Cuando se llama al Close método de la DrawingContext, el contenido del dibujo actual reemplaza cualquier contenido de DrawingVisualdibujo anterior definido para.When you call the Close method of the DrawingContext, the current drawing content replaces any previous drawing content defined for the DrawingVisual. Esto significa que no hay ninguna manera de anexar nuevo contenido de dibujo al contenido de dibujo existente.This means that there is no way to append new drawing content to existing drawing content.

Se aplica a

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