Graphics.IsVisible Method (RectangleF)

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

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

public bool IsVisible (
	RectangleF rect
)
public boolean IsVisible (
	RectangleF rect
)
public function IsVisible (
	rect : RectangleF
) : boolean
Not applicable.

Parameters

rect

RectangleF structure to test for visibility.

Return Value

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 using Replace.

  • Creates 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.

private void IsVisibleRectangleF(PaintEventArgs e)
{

    // Set clip region.
    Region clipRegion = new Region(new Rectangle(50, 50, 100, 100));
    e.Graphics.SetClip(clipRegion, CombineMode.Replace);

    // Set up coordinates of rectangles.
    RectangleF rect1 = new RectangleF(100.0F, 100.0F, 20.0F, 20.0F);
    RectangleF rect2 = new RectangleF(200.0F, 200.0F, 20.0F, 20.0F);

    // If rectangle is visible, fill it.
    if (e.Graphics.IsVisible(rect1))
    {
        e.Graphics.FillRectangle(new SolidBrush(Color.Red), rect1);
    }
    if (e.Graphics.IsVisible(rect2))
    {
        e.Graphics.FillRectangle(new SolidBrush(Color.Blue), rect2);
    }
}

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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