WinAPI: 测试 BitBlt

BitBlt(

  DestDC: HDC;                  {目标 DC}

  X, Y, Width, Height: Integer; {目标位置与大小}

  SrcDC: HDC;                   {源 DC}

  XSrc, YSrc: Integer;          {源起始位置}

  Rop: DWORD                    {光栅操作码, 也就是源像素与目标像素的混合方式}

): BOOL;



//可以使用光栅操作码的函数还有: PatBlt、StretchBlt、StretchDIBits


 
   

本例效果图:

---

代码文件:

---

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ExtCtrls;



type

  TForm1 = class(TForm)

    Panel1: TPanel;

    Panel2: TPanel;

    Panel3: TPanel;

    ListBox1: TListBox;

    procedure FormCreate(Sender: TObject);

    procedure FormDestroy(Sender: TObject);

    procedure FormPaint(Sender: TObject);

    procedure ListBox1Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



var

  bit1,bit2: TBitmap;

  cvs1,cvs2,cvs3: TCanvas;



procedure TForm1.FormCreate(Sender: TObject);

begin

  with ListBox1.Items do

  begin

    Add('SRCCOPY    ');

    Add('SRCPAINT   ');

    Add('SRCAND     ');

    Add('SRCINVERT  ');

    Add('SRCERASE   ');

    Add('NOTSRCCOPY ');

    Add('NOTSRCERASE');

    Add('MERGECOPY  ');

    Add('MERGEPAINT ');

    Add('PATCOPY    ');

    Add('PATPAINT   ');

    Add('PATINVERT  ');

    Add('DSTINVERT  ');

    Add('BLACKNESS  ');

    Add('WHITENESS  ');

  end;



  Panel1.Caption := '';

  Panel2.Caption := '';

  Panel3.Caption := '';



  bit1 := TBitmap.Create;

  bit1.Width := Panel1.ClientWidth;

  bit1.Height := Panel1.ClientHeight;



  bit2 := TBitmap.Create;

  bit2.Width := Panel2.ClientWidth;

  bit2.Height := Panel2.ClientHeight;





  cvs1 := TCanvas.Create;

  cvs2 := TCanvas.Create;

  cvs3 := TCanvas.Create;



  cvs1.Handle := GetDC(Panel1.Handle);

  cvs2.Handle := GetDC(Panel2.Handle);

  cvs3.Handle := GetDC(Panel3.Handle);

end;



procedure TForm1.FormDestroy(Sender: TObject);

begin

  bit1.Free;

  bit2.Free;

  cvs1.Free;

  cvs2.Free;

  cvs3.Free;

end;



procedure TForm1.FormPaint(Sender: TObject);

const

  ColorArr: array[0..5] of TColor = (clRed, clGreen, clBlue, clYellow, clFuchsia, clPurple);

var

  wi,hi: Integer;

  I: Integer;

begin

  wi := bit1.Width div 4;

  hi := bit1.Height div 4;



  bit1.Canvas.Pen.Width := 10;



  for I := 1 to 3 do

  begin

    bit1.Canvas.Pen.Color := ColorArr[i-1];

    bit1.Canvas.MoveTo(wi*i, 0);

    bit1.Canvas.LineTo(wi*i, bit1.Height);



    bit1.Canvas.Pen.Color := ColorArr[i+2];

    bit1.Canvas.MoveTo(0, hi*i);

    bit1.Canvas.LineTo(bit1.Width, hi*i);

  end;



  bit2.Canvas.Pen.Width := 15;

  bit2.Canvas.Ellipse(15, 15, bit2.Width-15, bit2.Height-15);



  cvs1.Draw(0, 0, bit1);

  cvs2.Draw(0, 0, bit2);

end;



procedure TForm1.ListBox1Click(Sender: TObject);

var

  Rop: Cardinal;

begin

  Repaint;

  Rop := SRCCOPY;

  case ListBox1.ItemIndex of

    0 : Rop := SRCCOPY    ;

    1 : Rop := SRCPAINT   ;

    2 : Rop := SRCAND     ;

    3 : Rop := SRCINVERT  ;

    4 : Rop := SRCERASE   ;

    5 : Rop := NOTSRCCOPY ;

    6 : Rop := NOTSRCERASE;

    7 : Rop := MERGECOPY  ;

    8 : Rop := MERGEPAINT ;

    9 : Rop := PATCOPY    ;

    10: Rop := PATPAINT   ;

    11: Rop := PATINVERT  ;

    12: Rop := DSTINVERT  ;

    13: Rop := BLACKNESS  ;

    14: Rop := WHITENESS  ;

  end;



  cvs3.Draw(0, 0, bit1);

  BitBlt(cvs3.Handle, (bit1.Width - bit2.Width) div 2, (bit1.Height - bit2.Height) div 2,

    bit2.Width, bit2.Height, bit2.Canvas.Handle, 0, 0, Rop);

end;



end.


 
   

窗体文件:

---

object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 300

  ClientWidth = 319

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  Position = poDesktopCenter

  OnCreate = FormCreate

  OnDestroy = FormDestroy

  OnPaint = FormPaint

  PixelsPerInch = 96

  TextHeight = 13

  object Panel1: TPanel

    Left = 8

    Top = 8

    Width = 180

    Height = 140

    Caption = 'Panel1'

    TabOrder = 0

  end

  object Panel2: TPanel

    Left = 194

    Top = 8

    Width = 119

    Height = 105

    Caption = 'Panel2'

    TabOrder = 1

  end

  object Panel3: TPanel

    Left = 8

    Top = 154

    Width = 180

    Height = 140

    Caption = 'Panel3'

    TabOrder = 2

  end

  object ListBox1: TListBox

    Left = 194

    Top = 119

    Width = 119

    Height = 176

    ItemHeight = 13

    TabOrder = 3

    OnClick = ListBox1Click

  end

end