Mega Code Archive
Capture the screen
<![CDATA[
Title: capture the screen?
uses
Graphics;
// Capture the entire screen
// Screenshot des gesamten Bildschirms
procedure ScreenShot(Bild: TBitMap);
var
c: TCanvas;
r: TRect;
begin
c := TCanvas.Create;
c.Handle := GetWindowDC(GetDesktopWindow);
try
r := Rect(0, 0, Screen.Width, Screen.Height);
Bild.Width := Screen.Width;
Bild.Height := Screen.Height;
Bild.Canvas.CopyRect(r, c, r);
finally
ReleaseDC(0, c.Handle);
c.Free;
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
Form1.Visible := False;
Sleep(750); // some delay, ein wenig Zeit geben
ScreenShot(Image1.Picture.BitMap);
Form1.Visible := True;
end;
// Only active window
// Screenshot des aktiven Fensters
procedure ScreenShotActiveWindow(Bild: TBitMap);
var
c: TCanvas;
r, t: TRect;
h: THandle;
begin
c := TCanvas.Create;
c.Handle := GetWindowDC(GetDesktopWindow);
h := GetForeGroundWindow;
if h 0 then
GetWindowRect(h, t);
try
r := Rect(0, 0, t.Right - t.Left, t.Bottom - t.Top);
Bild.Width := t.Right - t.Left;
Bild.Height := t.Bottom - t.Top;
Bild.Canvas.CopyRect(r, c, t);
finally
ReleaseDC(0, c.Handle);
c.Free;
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
Form1.Visible := False;
Sleep(750); //some delay,ein wenig Zeit geben
ScreenShotActiveWindow(Image1.Picture.BitMap);
Form1.Visible := True;
end;
{**********************************************}
// Another print screen function by Xavier P:
// Capture the entire screen
procedure ScreenShot(x: Integer;
y: Integer; //(x, y) = Left-top coordinate
Width: Integer;
Height: Integer; //(Width-Height) = Bottom-Right coordinate
bm: TBitMap); //Destination
var
dc: HDC;
lpPal: PLOGPALETTE;
begin
{test width and height}
if ((Width = 0) or
(Height = 0)) then
Exit;
bm.Width := Width;
bm.Height := Height;
{get the screen dc}
dc := GetDc(0);
if (dc = 0) then
Exit;
{do we have a palette device?}
if (GetDeviceCaps(dc, RASTERCAPS) and
RC_PALETTE = RC_PALETTE) then
begin
{allocate memory for a logical palette}
GetMem(lpPal,
SizeOf(TLOGPALETTE) +
(255 * SizeOf(TPALETTEENTRY)));
{zero it out to be neat}
FillChar(lpPal^,
SizeOf(TLOGPALETTE) +
(255 * SizeOf(TPALETTEENTRY)),
#0);
{fill in the palette version}
lpPal^.palVersion := $300;
{grab the system palette entries}
lpPal^.palNumEntries :=
GetSystemPaletteEntries(dc,
0,
256,
lpPal^.palPalEntry);
if (lpPal^.PalNumEntries 0) then
{create the palette}
bm.Palette := CreatePalette(lpPal^);
FreeMem(lpPal, SizeOf(TLOGPALETTE) +
(255 * SizeOf(TPALETTEENTRY)));
end;
{copy from the screen to the bitmap}
BitBlt(bm.Canvas.Handle,
0,
0,
Width,
Height,
Dc,
x,
y,
SRCCOPY);
{release the screen dc}
ReleaseDc(0, dc);
end;
// Example:
procedure TForm1.Button1Click(Sender: TObject);
begin
ScreenShot(0,0,Screen.Width, Screen.Height, Image1.Picture.Bitmap);
end;
{**********************************************}
// Capture a window
procedure ScreenShot(hWindow: HWND; bm: TBitmap);
var
Left, Top, Width, Height: Word;
R: TRect;
dc: HDC;
lpPal: PLOGPALETTE;
begin
{Check if valid window handle}
if not IsWindow(hWindow) then Exit;
{Retrieves the rectangular coordinates of the specified window}
GetWindowRect(hWindow, R);
Left := R.Left;
Top := R.Top;
Width := R.Right - R.Left;
Height := R.Bottom - R.Top;
bm.Width := Width;
bm.Height := Height;
{get the screen dc}
dc := GetDc(0);
if (dc = 0) then
begin
Exit;
end;
{do we have a palette device?}
if (GetDeviceCaps(dc, RASTERCAPS) and
RC_PALETTE = RC_PALETTE) then
begin
{allocate memory for a logical palette}
GetMem(lpPal,
SizeOf(TLOGPALETTE) +
(255 * SizeOf(TPALETTEENTRY)));
{zero it out to be neat}
FillChar(lpPal^,
SizeOf(TLOGPALETTE) +
(255 * SizeOf(TPALETTEENTRY)),
#0);
{fill in the palette version}
lpPal^.palVersion := $300;
{grab the system palette entries}
lpPal^.palNumEntries :=
GetSystemPaletteEntries(dc,
0,
256,
lpPal^.palPalEntry);
if (lpPal^.PalNumEntries 0) then
begin
{create the palette}
bm.Palette := CreatePalette(lpPal^);
end;
FreeMem(lpPal, SizeOf(TLOGPALETTE) +
(255 * SizeOf(TPALETTEENTRY)));
end;
{copy from the screen to the bitmap}
BitBlt(bm.Canvas.Handle,
0,
0,
Width,
Height,
Dc,
Left,
Top,
SRCCOPY);
{release the screen dc}
ReleaseDc(0, dc);
end;
// Example: Capture the foreground window:
procedure TForm1.Button1Click(Sender: TObject);
begin
ScreenShot(GetForeGroundWindow, Image1.Picture.Bitmap);
end;
{**********************************************}
// by Daniel Wischnewski
Sometimes you want to take a screen shot,
however often Windows has trouble with big data amounts and becomes very slow.
The simple solution is to make many small screen shots and paste the result together.
It's not light speed, however often faster than taking the whole screen at once.
const
cTileSize = 50;
function TForm1.GetSCREENSHOT: TBitmap;
var
Locked: Boolean;
X, Y, XS, YS: Integer;
Canvas: TCanvas;
R: TRect;
begin
Result := TBitmap.Create;
Result.Width := Screen.Width;
Result.Height := Screen.Height;
Canvas := TCanvas.Create;
Canvas.Handle := GetDC(0);
Locked := Canvas.TryLock;
try
XS := Pred(Screen.Width div cTileSize);
if Screen.Width mod cTileSize 0 then
Inc(XS);
YS := Pred(Screen.Height div cTileSize);
if Screen.Height mod cTileSize 0 then
Inc(YS);
for X := 0 to XS do
for Y := 0 to YS do
begin
R := Rect(
X * cTileSize, Y * cTileSize, Succ(X) * cTileSize,
Succ(Y) * cTileSize);
Result.Canvas.CopyRect(R, Canvas, R);
end;
finally
if Locked then
Canvas.Unlock;
ReleaseDC(0, Canvas.Handle);
Canvas.Free;
end;
end;
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