Region.IsVisible(INT, INT, INT, INT, const Graphics*) method
Applies to: desktop apps only
The Region::IsVisible method determines whether a rectangle intersects this region.
Syntax
BOOL IsVisible(
[in] INT x,
[in] INT y,
[in] INT width,
[in] INT height,
[in] const Graphics *g
) const;
Parameters
x [in]
Type: INTInteger that specifies the x-coordinate of the upper-left corner of the rectangle to test.
y [in]
Type: INTInteger that specifies the y-coordinate of the upper-left corner of the rectangle to test.
width [in]
Type: INTInteger that specifies the width of the rectangle to test.
height [in]
Type: INTInteger that specifies the height of the rectangle to test.
g [in]
Type: const Graphics*Optional. Pointer to a Graphics object that contains the world and page transformations required to calculate the device coordinates of this region and the rectangle. The default value is NULL.
Return value
Type:
Type: BOOL
If the rectangle intersects this region, the method returns TRUE; otherwise, it returns FALSE.
Examples
The following example creates a region from a path and then tests to determine whether a rectangle intersects the region.
VOID Example_IsVisibleXYWH(HDC hdc)
{
Graphics graphics(hdc);
Point points[] = {
Point(110, 20),
Point(120, 30),
Point(100, 60),
Point(120, 70),
Point(150, 60),
Point(140, 10)};
GraphicsPath path;
SolidBrush solidBrush(Color(255, 255, 0, 0));
path.AddClosedCurve(points, 6);
// Create a region from a path.
Region pathRegion(&path);
graphics.FillRegion(&solidBrush, &pathRegion);
// Check to see whether the rectangle intersects the region.
// The rectangle has upper-left corner (65, 25), width 70, and height 30.
if(pathRegion.IsVisible(65, 25, 70, 30, &graphics))
{
// All or part of the rectangle is in the region.
}
// Draw the rectangle.
Pen pen(Color(255, 0, 0, 0));
graphics.DrawRectangle(&pen, 65, 25, 70, 30);
}
Requirements
Minimum supported client |
Windows XP, Windows 2000 Professional |
Minimum supported server |
Windows 2000 Server |
Product |
GDI+ 1.0 |
Header |
Gdiplusheaders.h (include Gdiplus.h) |
Library |
Gdiplus.lib |
DLL |
Gdiplus.dll |
See also
Send comments about this topic to Microsoft
Build date: 3/6/2012