Interactive PowerBasic Forum

The following example creates an AdjustableArrowCap, pMyArrowCap, and sets the height of the cap. The code then creates a Pen, assigns pMyArrowCap as the ending line cap for this Pen, and draws a capped line. Next, the code gets the height of the arrow cap, creates a new arrow cap with height equal to the height of pMyArrowCap, assigns the new arrow cap as the ending line cap for the Pen, and draws another capped line.

C++


VOID Example_GetHeight(HDC hdc)
{
   Graphics graphics(hdc);

   // Create an AdjustableArrowCap with a height of 10 pixels.
   AdjustableArrowCap myArrow(10, 10, true);

   // Create a Pen, and assign myArrow as the end cap.
   Pen arrowPen(Color(255, 0, 0, 0));
   arrowPen.SetCustomEndCap(&myArrow);
   
   // Draw a line using arrowPen.
   graphics.DrawLine(&arrowPen, Point(0, 20), Point(100, 20));

   // Create a second arrow cap using the height of the first one.
   AdjustableArrowCap otherArrow(myArrow.GetHeight(), 20, true);

   // Assign the new arrow cap as the end cap for arrowPen.
   arrowPen.SetCustomEndCap(&otherArrow);

   // Draw a line using arrowPen.
   graphics.DrawLine(&arrowPen, Point(0, 55), Point(100, 55));
}


PowerBASIC


SUB GDIP_GetHeight(BYVAL hdc AS DWORD)

   LOCAL hStatus AS LONG
   LOCAL pGraphics AS DWORD
   LOCAL pArrowPen AS DWORD
   LOCAL pMyArrowCap AS DWORD
   LOCAL pOtherArrowCap AS DWORD
   LOCAL nHeight AS SINGLE

   hStatus = GdipCreateFromHDC(hdc, pGraphics)

   ' // Create an AdjustableArrowCap with a height of 10 pixels.
   hStatus = GdipCreateAdjustableArrowCap(10, 10, %TRUE, pMyArrowCap)

   ' // Create a Pen, and assign pMyArrowCap as the end cap.
   hStatus = GdipCreatePen1(GDIP_ARGB(255, 0, 0, 0), 1.0!, %UnitWorld, pArrowPen)
   hStatus = GdipSetPenCustomEndCap(pArrowPen, pMyArrowCap)

   ' // Draw a line using pArrowPen.
   hStatus = GdipDrawLineI(pGraphics, pArrowPen, 0, 20, 100, 20)

   ' // Get the height of the arrow cap.
   hStatus = GdipGetAdjustableArrowCapHeight(pMyArrowCap, nHeight)

   ' // Create a second arrow cap using the height of the first one.
   hStatus = GdipCreateAdjustableArrowCap(nHeight, 20, %TRUE, pOtherArrowCap)

   ' // Assign the new arrow cap as the end cap for pArrowPen.
   hStatus = GdipSetPenCustomEndCap(pArrowPen, pOtherArrowCap)

   ' // Draw a line using pArrowPen.
   hStatus = GdipDrawLineI(pGraphics, pArrowPen, 0, 55, 100, 55)

   ' // Cleanup
   IF pOtherArrowCap THEN GdipDeleteCustomLineCap(pOtherArrowCap)
   IF pMyArrowCap THEN GdipDeleteCustomLineCap(pMyArrowCap)
   IF pArrowPen THEN GdipDeletePen(pArrowPen)
   IF pGraphics THEN GdipDeleteGraphics(pGraphics)

END SUB


(http://www.jose.it-berater.org/captures/GdipGetAdjustableArrowCapHeight.png)