Rectangle::Union Method (Rectangle, Rectangle)

 

Gets a Rectangle structure that contains the union of two Rectangle structures.

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

public:
static Rectangle Union(
	Rectangle a,
	Rectangle b
)

Parameters

a
Type: System.Drawing::Rectangle

A rectangle to union.

b
Type: System.Drawing::Rectangle

A rectangle to union.

Return Value

Type: System.Drawing::Rectangle

A Rectangle structure that bounds the union of the two Rectangle structures.

When one of the two rectangles is empty, meaning all of its values are zero, the Union method returns a rectangle with a starting point of (0, 0), and the height and width of the non-empty rectangle. For example, if you have two rectangles: A = (0, 0; 0, 0) and B = (1, 1; 2, 2), then the union of A and B is (0, 0; 2, 2).

The following code example demonstrates how to use the Union method. This example is designed for use with a Windows Form. Paste this code into a form and call the ShowRectangleUnion method when handling the form's Paint event, passing e as PaintEventArgs.

private:
   void ShowRectangleUnion( PaintEventArgs^ e )
   {
      // Declare two rectangles and draw them.
      Rectangle rectangle1 = Rectangle(30,40,50,100);
      Rectangle rectangle2 = Rectangle(50,60,100,60);
      e->Graphics->DrawRectangle( Pens::Sienna, rectangle1 );
      e->Graphics->DrawRectangle( Pens::BlueViolet, rectangle2 );

      // Declare a third rectangle as a union of the first two.
      Rectangle rectangle3 = Rectangle::Union( rectangle1, rectangle2 );

      // Fill in the third rectangle in a semi-transparent color.
      Color transparentColor = Color::FromArgb( 40, 135, 135, 255 );
      e->Graphics->FillRectangle( gcnew SolidBrush( transparentColor ), rectangle3 );
   }

.NET Framework
Available since 1.1
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