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Graphics::IsVisible Method (Single, Single)

Indicates whether the point specified by a pair of coordinates is contained within the visible clip region of this Graphics.

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

public:
bool IsVisible(
	float x, 
	float y
)

Parameters

x
Type: System::Single

The x-coordinate of the point to test for visibility.

y
Type: System::Single

The y-coordinate of the point to test for visibility.

Return Value

Type: System::Boolean
true if the point defined by the x and y parameters 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 PaintEventArgs e, 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 using Replace.

  • Creates two points, one inside the clipping region and one outside.

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

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

public:
   void IsVisibleFloat( 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 points. 
      float x1 = 100.0F;
      float y1 = 100.0F;
      float x2 = 200.0F;
      float y2 = 200.0F;

      // If point is visible, fill ellipse that represents it. 
      if ( e->Graphics->IsVisible( x1, y1 ) )
      {
         e->Graphics->FillEllipse( gcnew SolidBrush( Color::Red ), x1, y1, 10.0F, 10.0F );
      }

      if ( e->Graphics->IsVisible( x2, y2 ) )
      {
         e->Graphics->FillEllipse( gcnew SolidBrush( Color::Blue ), x2, y2, 10.0F, 10.0F );
      }
   }

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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