The following example creates a
GraphicsPath object and adds five figures to the path. The code passes the address of that
GraphicsPath object to the
GdipCreatePathIter function to create an iterator that is associated with the path. The code calls the
GdipPathIterNextSubpathPath function twice to retrieve the second figure in the path. The
GdipDrawPath function draws that path in blue. Next, the code calls the
GdipPathIterRewind function and then calls
GdipPathIterNextSubpathPath once to obtain the first figure in the path. The
GdipDrawPath function draws that figure in red.
C++
VOID RewindExample(HDC hdc)
{
Graphics graphics(hdc);
// Create a graphics path with five figures (subpaths).
GraphicsPath path;
path.AddRectangle(Rect(20, 20, 60, 30)); // Subpath count is 1.
path.AddLine(100, 20, 160, 50); // Subpath count is 2.
path.AddArc(180, 20, 60, 30, 0.0f, 180.0f);
path.AddRectangle(Rect(260, 20, 60, 30)); // Subpath count is 3.
path.AddLine(340, 20, 400, 50); // Subpath count is 4.
path.AddArc(340, 20, 60, 30, 0.0f, 180.0f);
path.CloseFigure();
path.AddRectangle(Rect(420, 20, 60, 30)); // Subpath count is 5.
// Create an iterator, and associate it with the path.
GraphicsPathIterator iterator(&path);
// Get the second subpath by calling NextSubpath twice.
GraphicsPath subpath;
BOOL isClosed;
INT count;
count = iterator.NextSubpath(&subpath, &isClosed);
count = iterator.NextSubpath(&subpath, &isClosed);
// Draw the second figure in blue.
Pen bluePen(Color(255, 0, 0, 255));
graphics.DrawPath(&bluePen, &subpath);
// Rewind the iterator, and get the first figure in the path.
iterator.Rewind();
count = iterator.NextSubpath(&subpath, &isClosed);
// Draw the first figure in red.
Pen redPen(Color(255, 255, 0, 0));
graphics.DrawPath(&redPen, &subpath);
}
SUB GDIP_PathIterRewind (BYVAL hdc AS DWORD)
LOCAL hStatus AS LONG
LOCAL pGraphics AS DWORD
LOCAL pPath AS DWORD
LOCAL pIterator AS DWORD
LOCAL pSubPath AS DWORD
LOCAL pBluePen AS DWORD
LOCAL pRedPen AS DWORD
LOCAL count AS LONG
LOCAL isClosed AS LONG
hStatus = GdipCreateFromHDC(hdc, pGraphics)
' // Create a graphics path with five figures (subpaths).
hStatus = GdipCreatePath(%FillModeAlternate, pPath)
hStatus = GdipAddPathRectangle(pPath, 20, 20, 60, 30) ' // Subpath count is 1.
hStatus = GdipAddPathLine(pPath, 100, 20, 160, 50) ' // Subpath count is 2.
hStatus = GdipAddPathArc(pPath, 180, 20, 60, 30, 0, 180)
hStatus = GdipAddPathRectangle(pPath, 260, 20, 60, 30) ' // Subpath count is 3.
hStatus = GdipAddPathLine(pPath, 340, 20, 400, 50) ' // Subpath count is 4.
hStatus = GdipAddPathArc(pPath, 340, 20, 60, 30, 0, 180)
hStatus = GdipClosePathFigure(pPath)
hStatus = GdipAddPathRectangle(pPath, 420, 20, 60, 30) ' // Subpath count is 5.
' // Create an iterator, and associate it with the path.
hStatus = GdipCreatePathIter(pIterator, pPath)
' // Get the second subpath by calling NextSubpath twice.
hStatus = GdipCreatePath(%FillModeAlternate, pSubPath)
hStatus = GdipPathIterNextSubpathPath(pIterator, count, pSubPath, isClosed)
hStatus = GdipPathIterNextSubpathPath(pIterator, count, pSubPath, isClosed)
' // Draw the second figure in blue.
hStatus = GdipCreatePen1(GDIP_ARGB(255, 0, 0, 255), 1, %UnitWorld, pBluePen)
hStatus = GdipDrawPath(pGraphics, pBluePen, pSubPath)
' // Rewind the iterator, and get the first figure in the path.
hStatus = GdipPathIterRewind(pIterator)
hStatus = GdipPathIterNextSubpathPath(pIterator, count, pSubPath, isClosed)
' // Draw the first figure in red.
hStatus = GdipCreatePen1(GDIP_ARGB(255, 255, 0, 0), 1, %UnitWorld, pRedPen)
hStatus = GdipDrawPath(pGraphics, pRedPen, pSubPath)
' // Cleanup
IF pBluePen THEN GdipDeletePen(pBluePen)
IF pRedPen THEN GdipDeletePen(pRedPen)
IF pIterator THEN GdipDeletePathIter(pIterator)
IF pSubPath THEN GdipDeletePath(pSubPath)
IF pPath THEN GdipDeletePath(pPath)
IF pGraphics THEN GdipDeleteGraphics(pGraphics)
END SUB
(http://www.jose.it-berater.org/captures/GdipPathIterRewind.png)