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'GetDeviceCaps'에 해당되는 글 3건

2007/09/11 TDesktopCanvas - draw on Windows Desktop
2007/09/11 How to Convert Pixels to Millimeters
2007/09/11 How to capture Windows Desktop to Bitmap

2007/09/11 08:01

TDesktopCanvas - draw on Windows Desktop

2007/09/11 08:01 in Borland Delphi

This canvas class allows you to access the Windows Desktop, and draw on it.

type
  TDesktopCanvas = class(TCanvas)
   private
   DC : hDC;
   function GetWidth:Integer;
   function GetHeight:Integer;
   public
   constructor Create;
   destructor Destroy; override;
   published
   property Width: Integer read GetWidth;
   property Height: Integer read GetHeight;
   end;

{ TDesktopCanvas object }
function TDesktopCanvas.GetWidth:Integer;
begin
   Result:GetDeviceCaps(Handle,HORZRES) ;
end;

function TDesktopCanvas.GetHeight:Integer;
begin
   Result:=GetDeviceCaps(Handle,VERTRES) ;
end;

constructor TDesktopCanvas.Create;
begin
   inherited Create;
   DC := GetDC(0) ;
   Handle := DC;
end;

destructor TDesktopCanvas.Destroy;
begin
   Handle := 0;
   ReleaseDC(0, DC) ;
   inherited Destroy;
end;

Posted by Super Coder

Delphi Graphics and Drawing, GetDeviceCaps, TDesktopCanvas

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2007/09/11 07:44

How to Convert Pixels to Millimeters

2007/09/11 07:44 in Borland Delphi

If you need to convert pixel value to millimeters (inches, centimeters, etc.) use the code provided here.

The code uses the API functionGetDeviceCaps to get the metrics you need.

procedure PixelsPerMM(
canvas: TCanvas;
var x, y: single) ;
var
H:HDC;
hres,vres,
hsiz,vsiz:integer;
begin
H:=canvas.handle;
hres := GetDeviceCaps(H,HORZRES) ; {display width in pixels}
vres := GetDeviceCaps(H,VERTRES) ; {display height in pixels}
hsiz := GetDeviceCaps(H,HORZSIZE) ; {display width in mm}
vsiz := GetDeviceCaps(H,VERTSIZE) ; {display height in mm}
x := hres/hsiz;
y := vres/vsiz;
end;

Posted by Super Coder

Delphi Graphics and Drawing, GetDeviceCaps

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2007/09/11 07:43

How to capture Windows Desktop to Bitmap

2007/09/11 07:43 in Borland Delphi

Here's a piece of Delphi code capable of capturing the Windows Desktop image into a TBitmap object:

procedure ScreenShot(DestBitmap : TBitmap) ;
var
DC : HDC;
begin
DC :=GetDC GetDesktopWindow) ;
try
DestBitmap.Width :=GetDeviceCaps (DC, HORZRES) ;
DestBitmap.Height := GetDeviceCaps (DC, VERTRES) ;
BitBlt(DestBitmap.Canvas.Handle,
   0,
   0,
   DestBitmap.Width,
   DestBitmap.Height,
   DC,
   0,
   0,
   SRCCOPY) ;
finally
ReleaseDC (GetDesktopWindow, DC) ;
end;
end;

Posted by Super Coder