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DrawingContext.Pop Method

Pops the last opacity mask, opacity, clip, effect, or transform operation that was pushed onto the drawing context.

Namespace:  System.Windows.Media
Assembly:  PresentationCore (in PresentationCore.dll)

public abstract void Pop()

Once an operation is popped, it is no longer applied to subsequent drawing commands.

The following example shows the effect of the Pop command.

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Navigation;

namespace SDKSample
{


    public class PopExample : Page
    {

        public PopExample()
        {
            Pen shapeOutlinePen = new Pen(Brushes.Black, 2);
            shapeOutlinePen.Freeze();

            // Create a DrawingGroup
            DrawingGroup dGroup = new DrawingGroup();

            // Obtain a DrawingContext from  
            // the DrawingGroup. 
            using(DrawingContext dc = dGroup.Open())
            {
                // Draw a rectangle at full opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(0, 0, 25, 25));

                // Push an opacity change of 0.5.  
                // The opacity of each subsequent drawing will 
                // will be multiplied by 0.5.
                dc.PushOpacity(0.5);

                // This rectangle is drawn at 50% opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(25, 25, 25, 25));

                // Push an opacity change of 0.5.  
                // The opacity of each subsequent drawing will 
                // will be multiplied by 0.5. Note that 
                // push operations are cumulative (until they are 
                // popped). 
                dc.PushOpacity(0.5);

                // This rectangle is drawn at 25% opacity (0.5 x 0.5). 
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(50, 50, 25, 25));

                // Changes the opacity back to 0.5.
                dc.Pop();

                // This rectangle is drawn at 50% opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(75, 75, 25, 25));

                // Changes the opacity back to 1.0.
                dc.Pop();

                // This rectangle is drawn at 100% opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(100, 100, 25, 25));
            }

            // Display the drawing using an image control.
            Image theImage = new Image();
            DrawingImage dImageSource = new DrawingImage(dGroup);
            theImage.Source = dImageSource;

            this.Content = theImage;

        }




    }

}

The following illustration shows this example's output:

Rectangles drawn with different opacity values

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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