Region Class

A region is scalable because its coordinates are specified in world coordinates. On a drawing surface, however, its interior is dependent on the size and shape of the pixels representing it. An application can use regions to clip the output of drawing operations. These regions are called clipping regions. For more information on using regions for clipping, see How to: Use Clipping with a Region.

An application can also use regions in hit-testing operations, such as checking whether a point or a rectangle intersects a region. For more information on using regions for hit-testing, see How to: Use Hit Testing with a Region.

An application can fill a region by using the Graphics.FillRegion method and a Brush object.

The following code example is designed for use with Windows Forms, and it requires PaintEventArgs e, which is a parameter of the Paint event handler. The code example demonstrates how to use the Data from one RegionData object to set the Data for another RegionData.

private void DemonstrateRegionData2(PaintEventArgs e)
{

    //Create a simple region.
    Region region1 = new Region(new Rectangle(10, 10, 100, 100));

    // Extract the region data.
    System.Drawing.Drawing2D.RegionData region1Data = region1.GetRegionData();
    byte[] data1;
    data1 = region1Data.Data;

    // Create a second region.
    Region region2 = new Region();

    // Get the region data for the second region.
    System.Drawing.Drawing2D.RegionData region2Data = region2.GetRegionData();

    // Set the Data property for the second region to the Data from the first region.
    region2Data.Data = data1;

    // Construct a third region using the modified RegionData of the second region.
    Region region3 = new Region(region2Data);

    // Dispose of the first and second regions.
    region1.Dispose();
    region2.Dispose();

    // Call ExcludeClip passing in the third region.
    e.Graphics.ExcludeClip(region3);

    // Fill in the client rectangle.
    e.Graphics.FillRectangle(Brushes.Red, this.ClientRectangle);

    region3.Dispose();

}

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

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