(*----下面这个程序介绍了我们在使用线程及未使用线程二种情况下,运行该程序的反
应。当点UsedThread按钮时,则建立一个线程,这时我们可以在程序进行计算的同
时,改变窗体的尺寸及移动它。当按下NoUsedThread按钮时,不建立线程,我们会发
现在程序没有计算完之前根本不能做其它任何事情!
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Buttons;
type
TForm1 = class(TForm)
UsedThread: TBitBtn;
NoUsedThread: TBitBtn;
procedure UsedThreadClick(Sender: TObject);
procedure NoUsedThreadClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
function MyThreadFunc(P:pointer):Longint;stdcall;
var
i:longint;
DC:HDC;
S:string;
begin
DC:=GetDC(Form1.Handle);
for i:=0 to 500000 do begin
S:=Inttostr(i);
Textout(DC,10,10,Pchar(S),length(S));
end;
ReleaseDC(Form1.Handle,DC);
end;
procedure TForm1.UsedThreadClick(Sender: TObject);
var
hThread:Thandle;//定义一个句柄
ThreadID:DWord;
begin
//创建线程,同时线程函数被调用
hthread:=CreateThread(nil,0,@MyThreadfunc,nil,0,ThreadID);
if hThread=0 then
messagebox(Handle,'Didn’tCreateaThread',nil,MB_OK);
end;
procedure TForm1.NoUsedThreadClick(Sender: TObject);
begin
MyThreadfunc(nil);
//没有创建线程时,直接调用线程函数
end;
end.
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