How to make a transparent window
2000-08-01 · - · 仙 时间
I don't know what the transparent window is used, but after all, as a skill, still take it out. The following example demonstrates how to display a transparent window. At the same time, it also introduces how to capture the screen. You must set the Form1's Border attribute to BSNONE C Builder, please refer to Delphi example
Delphi
Unit homepage_coolformation; interfaceuses
Windows, Messages, Sysutils, Classes, Graphics, Controls, Forms, Dialogs
Extctrls, stdctrls, buttons;
TYPE TFORM1 = Class (TFORM)
Procedure FormPaint (Sender: TOBJECT);
Procedure FormShow (Sender: TOBJECT);
Procedure FormDestroy (Sender: TOBJECT);
Private {private declarations}
PUBLIC {public declarations}
HBMP: Integer;
END;
Var Form1: TFORM1;
IMPLEMentation
{$ R * .dfm}
Function CopyScreenTOBITMAP (RECT: TRECT): Integer;
VAR
HSCRDC, HMEMDC, HBitmap, Holdbitmap: Integer
NX, NY, NX2, NY2: Integer;
NWIDTH, NHEIGHT: Integer;
XSCRN, YSCRN: Integer;
Begin
IF (IsRectempty (Rect)) THEN
Begin
Result: = 0;
EXIT;
End; // Get the handle of the screen buffer.
// a Memory DC Compatible to Screen DC
HSCRDC: = Createdc ('Display', Pchar (0), PCHAR (0), PDEviceModea (0));
HMEMDC: = CreateCompatiPLEDC (HSCRDC);
// Get Points of Rectangle to grab
NX: = Rect.Left;
NY: = Rect.top;
NX2: = Rect.right;
NY2: = Rect.bottom;
// Get Screen Resolution
Xscrn: = getDeviceCaps (HSCRDC, Horzres);
YSCRN: = GetDeviceCaps (HSCRDC, Vertres);
// Make Sure Bitmap Rectangle Is Visible
IF (NX <0) THEN
Nx: = "0;"
IF (NY <0) THEN
NY: = "0;"
IF (nx2> xscrn) THEN
NX2: = xscrn;
IF (NY2> YSCRN) THEN
NY2: = YSCRN;
NWIDTH: = NX2 - NX;
NHEIGHT: = NY2 - NY;
// Create a Bitmap Compatible with the screen DC
Hbitmap: = CreateCompATIBLEBITMAP (HSCRDC, NWIDTH, NHEIGHT);
// Select New Bitmap Into Memory DC
Holdbitmap: = SelectObject (HMEMDC, HBitmap); // Bitblt Screen DC to Memory DC
Bitblt (HMEMDC, 0, 0, NWIDTH, NHEIGHT, HSCRDC, NX, NY, SRCCOPY);
// Select Old Bitmap Back Into Memory DC and Get Handle To
// Bitmap of the screen
Hbitmap: = SelectObject (HMEMDC, Holdbitmap);
// Clean Up
Deletedc (HSCRDC);
Deletedc (HMEMDC);
Result: = hbitmap;
END;
Procedure TFORM1.FORMSHOW (Sender: TOBJECT);
VAR
RECT: TRECT;
p: tpoint;
Begin
Rect: = ClientRect;
P: = Clientorigin;
Rect.Left: = p.x;
Rect.top:=p.y;
Rect.bottom: = Rect.bottom P.y;
Rect.right: = Rect.right p.x;
HBMP: = COPYSCREENTOBITMAP (RECT);
inherited;
END;
Procedure TFORM1.FORMPAINT (Sender: TOBJECT);
VAR
Bitmap: tbitmap;
RECT: TRECT;
Begin
Bitmap: = Tbitmap.create;
Bitmap.handle: = HBMP;
Rect: = ClientRect;
Canvas.draw (Rect.Left, Rect.top, Bitmap);
Bitmap.handle: = 0;
Bitmap.free;
END;
Procedure TFORM1.FORMDESTROY (Sender: TOBJECT);
Begin
DeleteObject (HBMP);
END;
End.
