TThread类初探

TThread类   Thread类是Delphi语言提供的线程类,该线程类可以完成大多数的线程操作

TThread类的属性   

 1.(1)FreeOnTerminate属性      

 当线程终止时是否自动删除线程对象.默认值为True;  语法：property FreeOnTerminate: Boolean;   

2 Priority属性      指定线程的优先级.   property Priority: TTreadPriority;      

3 ReturnValue属性       线程终止时,用该属性为其他线程传递一个返回值.   

 4 Suspended属性      指定线程是否处于挂起状态   

 5 Terminated       线程运行晨,如果将属性为True时,线程终止  

 6 ThreadID属性      线程的惟一标识   

7 Handle属性      线程句柄    

TThread类方法    

 DoTerminate: 调用线程对象DoTerminate方法可以触发线程的OnTerminate事件    

 Execute:线程的执行部分都写在该有方法中.必须实现的    

 Resume:当线程对象处于暂停状态时,调用此方法可以恢复线程运行   

  Suspend:暂停线程    

 Synchronize:线程同步    

 Terminate:终止线程    

 WaitFor:等待线程对象的终止,并返回线程对象的ReturnValue属性值   

unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ComCtrls;

type

  TMyThread = class(TThread)
   protected
      procedure Run();
      procedure Execute;override;
  end;

  

  TfrmDemo = class(TForm)
    ProgressBar1: TProgressBar;
    Button1: TButton;
    Button2: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmDemo: TfrmDemo;

implementation

{$R *.dfm}

{ TMyThread }

procedure TMyThread.Execute;
begin
  inherited;
  //线程同步
  Synchronize(Run);
end;

procedure TMyThread.Run;
var
  I: Integer;
begin  
  with frmDemo do 
  begin 
     for I := 0 to ProgressBar1.Max do
    begin 
     Label1.Caption := '工作线程运行中';
     ProgressBar1.Position := i;
     Application.ProcessMessages;  
    end;
  end;
end;

procedure TfrmDemo.Button1Click(Sender: TObject);
var
  I: Integer;
begin
  for I := 0 to ProgressBar1.Max do
  begin 
     Label1.Caption := '主线程运行中';
     ProgressBar1.Position := i;
     Application.ProcessMessages;
  end;
end;

procedure TfrmDemo.Button2Click(Sender: TObject);
var 
  MyThread: TMyThread;
begin
  MyThread := TMyThread.Create(false);  
end;

procedure TfrmDemo.FormCreate(Sender: TObject);
begin
  progressbar1.Max := 1000000;
end;

end.