Export (0) Print
Expand All

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
)

Parameters

rect
Type: System.Drawing.RectangleF

RectangleF 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 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 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);
    }
}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Show:
© 2014 Microsoft