GraphicsPathIterator::NextSubpath(INT*,INT*,BOOL*) method (gdipluspath.h)
The GraphicsPathIterator::NextSubpath method gets the starting index and the ending index of the next subpath (figure) in this iterator's associated path.
Syntax
INT NextSubpath(
INT *startIndex,
INT *endIndex,
BOOL *isClosed
);
Parameters
startIndex
Pointer to an INT that receives the starting index.
endIndex
Pointer to an INT that receives the ending index.
isClosed
Pointer to a BOOL that receives a value that indicates whether the obtained figure is closed. If the figure is closed, the received value is TRUE; otherwise, the received value is FALSE.
Return value
This method returns the number of data points in the next figure. If there are no more figures in the path, this method returns 0.
Remarks
The first time you call the GraphicsPathIterator::NextSubpath method of an iterator, it gets the indices for the first figure (subpath) of that iterator's associated path. The second time, it gets the indices for the second figure, and so on. Each time you call GraphicsPathIterator::NextSubpath, it returns the number of data points in the figure whose indices were retrieved. When there are no figures remaining, it returns 0.
Examples
The following example creates a GraphicsPath object and adds five figures to the path. The code passes the address of that GraphicsPath object to a GraphicsPathIterator constructor to create an iterator that is associated with the path. The code calls the iterator's GraphicsPathIterator::NextSubpath method three times to obtain the starting index and the ending index of the path's third figure. Then the code calls the iterator's GraphicsPathIterator::CopyData method to retrieve the third figure's data points.
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;
}
Requirements
| Requirement | Value |
|---|---|
| Header | gdipluspath.h |
See also
Constructing and Drawing Paths
GraphicsPathIterator::CopyData
GraphicsPathIterator::GetSubpathCount