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Graphics.IsVisible Method (Single, Single, Single, Single)

Indicates whether the rectangle specified by a pair of coordinates, a width, and a height 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,
	float width,
	float height
)

Parameters

x
Type: System.Single

The x-coordinate of the upper-left corner of the rectangle to test for visibility.

y
Type: System.Single

The y-coordinate of the upper-left corner of the rectangle to test for visibility.

width
Type: System.Single

Width of the rectangle to test for visibility.

height
Type: System.Single

Height of the rectangle to test for visibility.

Return Value

Type: System.Boolean
true if the rectangle defined by the x, y, width, and height 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 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.

private void IsVisible4Float(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. 
    float x1 = 100.0F;
    float y1 = 100.0F;
    float width1 = 20.0F;
    float height1 = 20.0F;
    float x2 = 200.0F;
    float y2 = 200.0F;
    float width2 = 20.0F;
    float height2 = 20.0F;

    // If rectangle is visible, fill it. 
    if (e.Graphics.IsVisible(x1, y1, width1, height1))
    {
        e.Graphics.FillRectangle(new SolidBrush(Color.Red), x1, y1, width1, height1);
    }
    if (e.Graphics.IsVisible(x2, y2, width2, height2))
    {
        e.Graphics.FillRectangle(new SolidBrush(Color.Blue), x2, y2, width2, height2);
    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
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