GDI+: GdipRecordMetafileFileName

[José Roca]

 

Recording Metafiles

The following example creates a Metafile. The code uses the Metafile to record a sequence of graphics commands and then saves the recorded commands in a file named SampleMetafile.emf. Note that the function that creates the metafile (GdipRecordMetafileFileName) receives a device context handle, and we retrieve a Graphics handle calling the GdipGetImageGraphicsContext function passing the metafile handle. The recording stops (and the recorded commands are saved to the file) when the Graphics handle is deleted with GdipDeleteGraphics. To display the metafile, a new Graphics handle is retrieved calling the GdipCreateFromHDC function and passing the Graphics and Metafile handles to the GdipDrawImage function. Note that the code uses the same Metafile handle to record and to display (play back) the metafile. A metafile contains its own graphics state, which is defined by the Graphics object used to record the metafile. Any properties of the Graphics object (clip region, world transformation, smoothing mode, and the like) that you set while recording the metafile will be stored in the metafile. When you display the metafile, the drawing will be done according to those stored properties.

C++

Code Select Expand


Metafile metafile(L"SampleMetafile.emf", hdc);
{
   Graphics graphics(&metafile);
   Pen greenPen(Color(255, 0, 255, 0));
   SolidBrush solidBrush(Color(255, 0, 0, 255));

   // Add a rectangle and an ellipse to the metafile.
   graphics.DrawRectangle(&greenPen, Rect(50, 10, 25, 75));
   graphics.DrawEllipse(&greenPen, Rect(100, 10, 25, 75));

   // Add an ellipse (drawn with antialiasing) to the metafile.
   graphics.SetSmoothingMode(SmoothingModeHighQuality);
   graphics.DrawEllipse(&greenPen, Rect(150, 10, 25, 75));

   // Add some text (drawn with antialiasing) to the metafile.
   FontFamily fontFamily(L"Arial");
   Font font(&fontFamily, 24, FontStyleRegular, UnitPixel);
   
   graphics.SetTextRenderingHint(TextRenderingHintAntiAlias);
   graphics.RotateTransform(30.0f);
   graphics.DrawString(L"Smooth Text", 11, &font,
      PointF(50.0f, 50.0f), &solidBrush);
} // End of recording metafile.

// Play back the metafile.
Graphics playbackGraphics(hdc);
playbackGraphics.DrawImage(&metafile, 200, 100);


PowerBASIC

Code Select Expand


SUB GDIP_RecordMetafile (BYVAL hdc AS DWORD)

   LOCAL hStatus AS LONG
   LOCAL pMetafile AS DWORD
   LOCAL pGraphics AS DWORD
   LOCAL pPlaybackGraphics AS DWORD
   LOCAL pGreenPen AS DWORD
   LOCAL pSolidBrush AS DWORD
   LOCAL pFontFamily AS DWORD
   LOCAL pFont AS DWORD
   LOCAL strFileName AS STRING
   LOCAL strDesc AS STRING
   LOCAL strFontName AS STRING
   LOCAL strText AS STRING
   LOCAL rcf AS RECTF

   ' // Create a Metafile object for recording
   strFileName = UCODE$("SampleMetafile.emf")
   strDesc = UCODE$("")
   hStatus = GdipRecordMetafileFileName(STRPTR(strFileName), hdc, _
             %EmfTypeEmfPlusDual, BYVAL %NULL, %MetafileFrameUnitGdi, _
             STRPTR(strDesc), pMetafile)

   IF pMetaFile THEN
      ' // Create a Graphics object that is associated with the Metafile object
      hStatus = GdipGetImageGraphicsContext(pMetafile, pGraphics)
      IF pGraphics THEN
         ' // Create a pen and a solid brush
         hStatus = GdipCreatePen1(GDIP_ARGB(255, 0, 255, 0), 1, %UnitPixel, pGreenPen)
         hStatus = GdipCreateSolidFill(GDIP_ARGB(255, 0, 0, 255), pSolidBrush)
         ' // Add a rectangle and an ellipse to the metafile
         hStatus = GdipDrawRectangle(pGraphics, pGreenPen, 50, 10, 25, 75)
         hStatus = GdipDrawEllipse(pGraphics, pGreenPen, 100, 10, 25, 75)
         ' // Add an ellipse (drawn with antialiasing) to the metafile.
         hStatus = GdipSetSmoothingMode(pGraphics, %SmoothingModeHighQuality)
         hStatus = GdipDrawEllipse(pGraphics, pGreenPen, 150, 10, 25, 75)
         ' // Add some text (drawn with antialiasing) to the metafile.
         strFontName = UCODE$("Arial")
         hStatus = GdipCreateFontFamilyFromName(STRPTR(strFontName), %NULL, pFontFamily)
         IF pFontFamily THEN
            hStatus = GdipCreateFont(pFontFamily, 24, %FontStyleRegular, %UnitPixel, pFont)
            GdipDeleteFontFamily(pFontFamily)
         END IF
         hStatus = GdipSetTextRenderingHint(pGraphics, %TextRenderingHintAntiAlias)
         hStatus = GdipRotateWorldTransform(pGraphics, 30.0!, %MatrixOrderPrepend)
         strText = UCODE$("Smooth Text")
         rcf.x = 50.0! : rcf.y = 50.0!
         hStatus = GdipDrawString(pGraphics, STRPTR(strText), LEN(strText) \ 2, pFont, rcf, %NULL, pSolidBrush)
         ' // Stop recording by deleting the Graphics object
         GdipDeleteGraphics(pGraphics)
         ' // Free resources
         IF pFont THEN GdipDeleteFont(pFont)
         IF pSolidBrush THEN GdipDeleteBrush(pSolidBrush)
         IF pGreenPen THEN GdipDeletePen(pGreenPen)
      END IF
   END IF

   ' // Create a Graphics object that is associated with the device context
   hStatus = GdipCreateFromHDC(hdc, pPlaybackGraphics)
   IF pPlaybackGraphics THEN
      ' // Display the metafile
      hStatus = GdipDrawImage(pPlaybackGraphics, pMetafile, 200, 100)
      ' // Delete the Graphics object
      GdipDeleteGraphics(pPlaybackGraphics)
   END IF

   ' // Dispose the Metafile object
   IF pMetafile THEN GdipDisposeImage(pMetafile)

END SUB