Советы по Delphi

         

Как создать не VCL дисплей для отображения текста и изображений?


Своим опытом делится Олег Кулабухов:

    procedure TForm1.Button1Click(Sender: TObject);
var
dc : hdc;
MemDc : hdc;
MemBitmap : hBitmap;
OldMemBitmap : hBitmap;
begin

{Get the handle to the screen's dc}
dc := GetDc(0);



{Create and retrieve a handle to a memory dc based on the screen}
MemDc := CreateCompatibleDc(dc);

{Create a bitmap that is compatible with the display.}
{Note: if you pass "MemDc" to CreateCompatibleBitmap()}
{instead of "dc", you will get a monochrome bitmap!}
MemBitmap := CreateCompatibleBitmap(dc, 100, 100);

{Release the screen dc}
ReleaseDc(0, dc);

{Select the bitmap surface into the MemDc}
{remembering the default bitmap}
OldMemBitmap := SelectObject(MemDc, MemBitmap);

{Draw on the MemoryDc}
PatBlt(MemDc, 0, 0, 100, 100, WHITENESS);
Ellipse(MemDc, 0, 0, 100, 100);

{Copy the MemDc to the Form Canvas}
BitBlt(Form1.Canvas.Handle,
100, 100,
100, 100,
MemDc,
0, 0,
SRCCOPY);

{Select the default bitmap back into the memory dc}
SelectObject(MemDc, OldMemBitmap);

{Note: You can now use the memory bitmap handle with}
{functions such as GetDiBits()}

{Delete the Memory Bitmap}
DeleteObject(MemBitmap);

{Delete the MemoryDc}
DeleteDc(MemDc);

end;

[001900]



Содержание раздела