Graphics.IntersectClip Method (Region)

 

Updates the clip region of this Graphics to the intersection of the current clip region and the specified Region.

Namespace:   System.Drawing
Assembly:  System.Drawing (in System.Drawing.dll)

public void IntersectClip(
	Region region
)

Parameters

region
Type: System.Drawing.Region

Region to intersect with the current region.

This method assigns to the Clip property of this Graphics the area represented by the intersection of the current clip region and the region specified by the region parameter.

The following code example is designed for use with Windows Forms, and it requires PaintEventArgse, which is a parameter of the Paint event handler. The code performs the following actions:

  • Creates a rectangle with upper-left corner at (0, 0).

  • Creates a region and sets it to the rectangle, and sets the clipping region to this region.

  • Creates a second rectangle with upper-left corner at (100, 100).

  • Creates a region and sets it to the second rectangle, and sets the clipping region to the intersection of this region and the current clipping region (the first rectangle) using a combine mode of Replace.

  • Fills a large rectangle that includes both previous regions with a solid blue brush.

  • Resets the clipping region to infinite.

  • Draws rectangles around the two clipping regions. It uses a black pen for the first clipping region and a red pen for the second clipping region.

The result is that only the intersection of the two regions is filled with blue.

private void IntersectClipRegion(PaintEventArgs e)
{

    // Set clipping region.
    Rectangle clipRect = new Rectangle(0, 0, 200, 200);
    Region clipRegion = new Region(clipRect);
    e.Graphics.SetClip(clipRegion, CombineMode.Replace);

    // Update clipping region to intersection of

    // existing region with specified rectangle.
    Rectangle intersectRect = new Rectangle(100, 100, 200, 200);
    Region intersectRegion = new Region(intersectRect);
    e.Graphics.IntersectClip(intersectRegion);

    // Fill rectangle to demonstrate effective clipping region.
    e.Graphics.FillRectangle(new SolidBrush(Color.Blue), 0, 0, 500, 500);

    // Reset clipping region to infinite.
    e.Graphics.ResetClip();

    // Draw clipRect and intersectRect to screen.
    e.Graphics.DrawRectangle(new Pen(Color.Black), clipRect);
    e.Graphics.DrawRectangle(new Pen(Color.Red), intersectRect);
}

.NET Framework
Available since 1.1
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