IsVisible Method (Rectangle)

Graphics::IsVisible Method (Rectangle)


Indicates whether the rectangle specified by a Rectangle structure is contained within the visible clip region of this Graphics.

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

bool IsVisible(
	Rectangle rect


Type: System.Drawing::Rectangle

Rectangle structure to test for visibility.

Return Value

Type: System::Boolean

true if the rectangle specified by the rect parameter is contained within the visible clip region of this Graphics; otherwise, false.

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 rectangular clipping region and sets it as the clipping region for the graphics object of the form usingReplace.

  • Creates the location and size of two rectangles, one inside the clipping region and one outside.

  • Tests each of the rectangles for visibility and draws only the visible one.

The result is one small red rectangle, which is within the clip region.

   void IsVisibleRectangle( PaintEventArgs^ e )
      // Set clip region.
      System::Drawing::Region^ clipRegion = gcnew System::Drawing::Region( Rectangle(50,50,100,100) );
      e->Graphics->SetClip( clipRegion, CombineMode::Replace );

      // Set up coordinates of rectangles.
      Rectangle rect1 = Rectangle(100,100,20,20);
      Rectangle rect2 = Rectangle(200,200,20,20);

      // If rectangle is visible, fill it.
      if ( e->Graphics->IsVisible( rect1 ) )
         e->Graphics->FillRectangle( gcnew SolidBrush( Color::Red ), rect1 );

      if ( e->Graphics->IsVisible( rect2 ) )
         e->Graphics->FillRectangle( gcnew SolidBrush( Color::Blue ), rect2 );

.NET Framework
Available since 1.1
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