delphi多线程编程5.doc

delphi多线程编程5窗体文件:object Form1: TForm1Left = 0Top = 0Caption = Form1ClientHeight = 206ClientWidth = 371Color = clBtnFaceFont.Charset = DEFAULT_CHARSETFont.Color = clWindowTextFont.Height = -11Font.Name = TahomaFont.Style = OldCreateOrder = FalseOnDestroy = FormDestroyPixelsPerInch = 96TextHeight = 13object PaintBox1: TPaintBoxLeft = 8Top = 8Width = 114Height = 153endobject PaintBox2: TPaintBoxLeft = 128Top = 8Width = 114Height = 153endobject PaintBox3: TPaintBoxLeft = 248Top = 8Width = 114Height = 153endobject Button1: TButtonLeft = 288Top = 172Width = 75Height = 25Caption = Button1TabOrder = 0OnClick = Button1Clickendend可以借助入口函数的参数, 把这个程序简化一下(窗体和运行效果不变):unit Unit1;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls, ExtCtrls;typeTForm1 = class(TForm)PaintBox1: TPaintBox;PaintBox2: TPaintBox;PaintBox3: TPaintBox;Button1: TButton;procedure Button1Click(Sender: TObject);procedure FormDestroy(Sender: TObject);end;varForm1: TForm1;implementation$R *.dfmvarh1,h2,h3: THandle;线程的入口函数: 不同的线程画不同颜色的椭圆function ThreadFun(p: Pointer): Integer; stdcall;vari,x1,y1,x2,y2: Integer;paint: TPaintBox;begincase Integer(p) of1: beginpaint := Form1.PaintBox1;paint.Canvas.Brush.Color := clRed;end;2: beginpaint := Form1.PaintBox2;paint.Canvas.Brush.Color := clGreenend;3: beginpaint := Form1.PaintBox3;paint.Canvas.Brush.Color := clBlue;end;end;for i := 0 to 5000 do with paint dobeginx1 := Random(Width); y1 := Random(Height);x2 := Random(Width); y2 := Random(Height);Canvas.Lock;Canvas.Ellipse(x1,y1,x2,y2);Canvas.Unlock;Sleep(0);end;Result := 0;end;procedure TForm1.Button1Click(Sender: TObject);varID: DWORD;beginh1 := CreateThread(nil, 0, ThreadFun, Ptr(1), 0, ID);h2 := CreateThread(nil, 0, ThreadFun, Ptr(2), 0, ID);h3 := CreateThread(nil, 0, ThreadFun, Ptr(3), 0, ID);end;procedure TForm1.FormDestroy(Sender: TObject);beginCloseHandle(h1);CloseHandle(h2);CloseHandle(h3);end;end.多用点数组, 再简化一下(窗体与效果一样):unit Unit1;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls, ExtCtrls;typeTForm1 = class(TForm)PaintBox1: TPaintBox;PaintBox2: TPaintBox;PaintBox3: TPaintBox;Button1: TButton;procedure Button1Click(Sender: TObject);procedure FormDestroy(Sender: TObject);end;varForm1: TForm1;implementation$R *.dfmconstcolors: array0.2 of TColor = (clRed, clGreen, clBlue);varhArr: array0.2 of THandle;panitArr: array0.2 of TPaintBox;function ThreadFun(p: Pointer): Integer; stdcall;vari,n,x1,y1,x2,y2: Integer;beginn := Integer(p);panitArrn.Color := colorsn;for i := 0 to 5000 do with panitArrn dobeginx1 := Random(Width); y1 := Random(Height);x2 := Random(Width); y2 := Random(Height);Canvas.Lock;Canvas.Ellipse(x1,y1,x2,y2);Canvas.Unlock;Sleep(0);end;Result := 0;end;procedure TForm1.Button1Click(Sender: TObject);varID: DWORD;i: Integer;beginpanitArr0 := PaintBox1;panitArr1 := PaintBox2;panitArr2 := PaintBox3;for i := 0 to Length(hArr) - 1 dohArr := CreateThread(nil, 0, ThreadFun, Ptr(i), 0, ID);end;procedure TForm1.FormDestroy(Sender: TObject);vari: Integer;beginfor i := 0 to Length(hArr) - 1 do CloseHandle(hArr);end;end.多线程编程(19) - 不使用同步工具, 手动协调线程依次执行。 在前面例子的基础上, 探讨新问题.假如我们想让几个线程(例子中是 3 个)依次执行, 我们可以使用临界区、信号、互斥等手段;但下面第一个例子什么同步工具都没用, 也达到了目的; 方法是: 让前一个线程在结束前顺便启动下一个线程.第二个例子使用了互斥对象配合 WaitForSingleObject 函数, 也达到相似的目的.效果图(两个例子的效果图差不多, 但第二个例子的执行顺序不好保证):第一个例子的代码文件:unit Unit1;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls, ExtCtrls;typeTForm1 = class(TForm)PaintBox1: TPaintBox;PaintBox2: TPaintBox;PaintBox3: TPaintBox;Button1: TButton;procedure Button1Click(Sender: TObject);procedure FormDestroy(Sender: TObject);end;varForm1: TForm1;implementation$R *.dfmconstcolors: array0.2 of TColor = (clRed, clGreen, clBlue);varhArr: array0.2 of THandle;panitArr: array0.2 of TPaintBox;function ThreadFun(p: Pointer): Integer; stdcall;vari,n,x1,y1,x2,y2: Integer;ThreadID: DWORD;beginn := Integer(p);panitArrn.Color := colorsn;for i := 0 to 50 do with panitArrn dobeginx1 := Random(Width); y1 := Random(Height);x2 := Random(Width); y2 := Random(Height);Canvas.Lock;Canvas.Ellipse(x1,y1,x2,y2);Canvas.Unlock;Sleep(2);end;在前一个线程收尾时, 如果新建线程不超过 3 个就继续建立Inc(n);if n 3 then hArrn := CreateThread(nil, 0, ThreadFun, Ptr(n), 0, ThreadID);Result := 0;end;procedure TForm1.Button1Click(Sender: TObject);varID: DWORD;beginpanitArr0 := PaintBox1;panitArr1 := PaintBox2;panitArr2 := PaintBox3;开始只建立了一个线程, 并传入 0 参数作为标识hArr0 := CreateThread(nil, 0, ThreadFun, Ptr(0), 0, ID);end;procedure TForm1.FormDestroy(Sender: TObject);vari: Integer;beginfor i := 0 to Length(hArr) - 1 do CloseHandle(hArr);end;end.窗体文件:object Form1: TForm1Left = 0Top = 0Caption = Form1ClientHeight = 156ClientWidth = 321Color = clBtnFaceFont.Charset = DEFAULT_CHARSETFont.Color = clWindowTextFont.Height = -11Font.Name = TahomaFont.Style = OldCreateOrder = FalseOnDestroy = FormDestroyPixelsPerInch = 96TextHeight = 13object PaintBox1: TPaintBoxLeft = 8Top = 8Width = 97Height = 113endobject PaintBox2: TPaintBoxLeft = 111Top = 8Width = 98Height = 113endobject PaintBox3: TPaintBoxLeft = 215Top = 8Width = 98Height = 113endobject Button1: TButtonLeft = 238Top = 126Width = 75Height = 25Caption = Button1TabOrder = 0OnClick = Button1Clickendend第一个例子的代码文件(窗体同上):unit Unit1;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls, ExtCtrls;typeTForm1 = class(TForm)PaintBox1: TPaintBox;PaintBox2: TPaintBox;PaintBox3: TPaintBox;Button1: TButton;procedure Button1Click(Sender: TObject);procedure FormDestroy(Sender: TObject);end;varForm1: TForm1;implementation$R *.dfmconstcolors: array0.2 of TColor = (clRed, clGreen, clBlue);varhArr: array0.2 of THandle;panitArr: array0.2 of TPaintBox;hMutex: THandle; 互斥对象的句柄function ThreadFun(p: Pointer): Integer; stdcall;vari,n,x1,y1,x2,y2: Integer;beginn := Integer(p);panitArrn.Color := colorsn;if WaitForSingleObject(hMutex, INFINITE) = WAIT_OBJECT_0 thenbeginfor i := 0 to