Region::IsVisible Method (RectangleF)

 

Tests whether any portion of the specified RectangleF structure is contained within this Region.

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

public:
bool IsVisible(
	RectangleF rect
)

Parameters

rect
Type: System.Drawing::RectangleF

The RectangleF structure to test.

Return Value

Type: System::Boolean

true when any portion of rect is contained within this Region; 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 the first rectangle and draws it to the screen in blue.

  • Creates the second rectangle and draws it to the screen in red.

  • Creates a region from the first rectangle.

  • Determines if any portion of the rectangle intersects with the region.

  • Displays the true or false result on the screen.

Notice that the rectangle intersects the region, so the result is true.

public:
   void IsVisible_RectF_Example( PaintEventArgs^ e )
   {
      // Create the first rectangle and draw it to the screen in blue.
      Rectangle regionRect = Rectangle(20,20,100,100);
      e->Graphics->DrawRectangle( Pens::Blue, regionRect );

      // Create the second rectangle and draw it to the screen in red.
      RectangleF myRect = RectangleF(90,30,100,100);
      e->Graphics->DrawRectangle( Pens::Red, Rectangle::Round( myRect ) );

      // Create a region using the first rectangle.
      System::Drawing::Region^ myRegion = gcnew System::Drawing::Region( regionRect );

      // Determine if myRect is contained in the region.
      bool contained = myRegion->IsVisible( myRect );

      // Display the result.
      System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",8 );
      SolidBrush^ myBrush = gcnew SolidBrush( Color::Black );
      e->Graphics->DrawString( String::Format( "contained = {0}", contained ), myFont, myBrush, PointF(20,140) );
   }

.NET Framework
Available since 1.1
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