Как получить доступ к объекту метафайла
Как получить доступ к объекту метафайла
Below is an example of getting metafile information and enumerating each metafile record :
functionMyEnhMetaFileProc(DC: HDC; {handle to device context}
lpHTable: PHANDLETABLE; {pointer to metafile handle table}
lpEMFR: PENHMETARECORD; {pointer to metafile record}
nObj: integer; {count of objects}
TheForm: TForm1): integer; stdcall;
begin
{draw the metafile record}
PlayEnhMetaFileRecord(dc, lpHTable^, lpEMFR^, nObj);
{set to zero to stop metafile enumeration}
result := 1;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
MyMetafile: TMetafile;
lpENHMETAHEADER: PENHMETAHEADER; {extra metafile info}
lpENHMETAHEADERSIZE: DWORD;
NumMetaRecords: DWORD;
begin
{Create a metafile}
MyMetafile := TMetafile.Create;
with TMetafileCanvas.Create(MyMetafile, 0) do
try
Brush.Color := clRed;
Ellipse(0, 0, 100, 100);
Ellipse(100, 100, 200, 200);
Ellipse(200, 200, 300, 300);
Ellipse(300, 300, 400, 400);
Ellipse(400, 400, 500, 500);
Ellipse(500, 500, 600, 600);
finally
Free;
end;
{we might as well get some extra metafile info}
lpENHMETAHEADERSIZE := GetEnhMetaFileHeader(MyMetafile.Handle, 0, nil);
NumMetaRecords := 0;
if (lpENHMETAHEADERSIZE > 0) then
begin
GetMem(lpENHMETAHEADER, lpENHMETAHEADERSIZE);
GetEnhMetaFileHeader(MyMetafile.Handle, lpENHMETAHEADERSIZE, lpENHMETAHEADER);
{Here is an example of getting number of metafile records}
NumMetaRecords := lpENHMETAHEADER^.nRecords;
{enumerate the records}
EnumEnhMetaFile(Canvas.Handle, MyMetafile.Handle, @MyEnhMetaFileProc, self,
Rect(0, 0, 600, 600));
FreeMem(lpENHMETAHEADER, lpENHMETAHEADERSIZE);
end;
MyMetafile.Free;
end;