Region.IsVisible(INT, INT, const Graphics*) method

Applies to: desktop apps only

The Region::IsVisible method determines whether a point is inside this region.

Syntax

BOOL IsVisible(
  [in]  INT x,
  [in]  INT y,
  [in]  const Graphics *g
) const;

Parameters

  • x [in]
    Type: INT

    Integer that specifies the x-coordinate of the point to test.

  • y [in]
    Type: INT

    Integer that specifies the y-coordinate of the point 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 point. The default value is NULL.

Return value

Type:

Type: BOOL

If the point is inside this region, this method returns TRUE; otherwise, it returns FALSE.

Examples

The following example creates a region from a path and then tests to determine whether a point is inside the region.

VOID Example_IsVisibleXY(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 point (125, 40) is in the region.
   INT x = 125;
   INT y = 40;
   if(pathRegion.IsVisible(x, y, &graphics))
   {

      // The point is in the region.
   }

   // Fill a small circle centered at the point (125, 40).
   SolidBrush brush(Color(255, 0, 0, 0));
   graphics.FillEllipse(&brush, x - 4, y - 4, 8, 8);
}

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

Region

Graphics

Rect

 

 

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Build date: 3/6/2012