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
GdipPathIterNextSubpath function three times to obtain the starting index and the ending index of the path's third figure. Then the code calls the
GdipPathIterCopyData function to retrieve the third figure's data points.
C++
VOID NextSubpathExample2(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);
// Call NextSubpath three times to get the starting and ending
// indices for the third figure.
INT start;
INT end;
BOOL isClosed;
INT count;
count = iterator.NextSubpath(&start, &end, &isClosed);
count = iterator.NextSubpath(&start, &end, &isClosed);
count = iterator.NextSubpath(&start, &end, &isClosed);
// Get the third figure's data points.
PointF* points = new PointF[count];
BYTE* types = new BYTE[count];
iterator.CopyData(points, types, start, end);
// Draw the third figure's data points.
SolidBrush brush(Color(255, 255, 0, 0));
for(INT j = 0; j < count; ++j)
graphics.FillEllipse(
&brush,
points[j].X - 3.0f,
points[j].Y - 3.0f,
6.0f,
6.0f);
delete points;
delete types;
}
SUB GDIP_PathIterNextSubpath (BYVAL hdc AS DWORD)
LOCAL hStatus AS LONG
LOCAL pGraphics AS DWORD
LOCAL pPath AS DWORD
LOCAL pIterator AS DWORD
LOCAL pBrush AS DWORD
LOCAL count AS LONG
LOCAL resultCount AS LONG
LOCAL startIndex AS LONG
LOCAL endIndex AS LONG
LOCAL isClosed AS LONG
LOCAL i AS LONG
DIM pPoints(0) AS POINTF
DIM pTypes(0) AS BYTE
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)
' // Call NextSubpath three times to get the starting and ending indices for the third figure.
hStatus = GdipPathIterNextSubpath(pIterator, count, startIndex, endIndex, isClosed)
hStatus = GdipPathIterNextSubpath(pIterator, count, startIndex, endIndex, isClosed)
hStatus = GdipPathIterNextSubpath(pIterator, count, startIndex, endIndex, isClosed)
' // Get the third figure's data points.
IF count THEN
REDIM pPoints(count - 1)
REDIM pTypes(count - 1)
hStatus = GdipPathIterCopyData(pIterator, resultCount, pPoints(0), pTypes(0), startIndex, endIndex)
' // Draw the third figure's data points.
hStatus = GdipCreateSolidFill(GDIP_ARGB(255, 255, 0, 0), pBrush)
FOR i = 0 TO count - 1
hStatus = GdipFillEllipse(pGraphics, pBrush, pPoints(i).x - 3, pPoints(i).y - 3, 6, 6)
NEXT
END IF
' // Cleanup
IF pBrush THEN GdipDeleteBrush(pBrush)
IF pIterator THEN GdipDeletePathIter(pIterator)
IF pPath THEN GdipDeletePath(pPath)
IF pGraphics THEN GdipDeleteGraphics(pGraphics)
END SUB
(http://www.jose.it-berater.org/captures/GdipPathIterNextSubpath.png)