lazarus开发界面程序用线程显示进度条

lazarus开发界面程序用线程显示进度条，效果更好，以前没有另外显示线程，遇到上传文件或其他较长时间操作，界面就卡在那里，体验不好，现在另外启动线程操作，主界面就不至于卡在那里。

首先在主界面上定义线程 

type{ TMyBackupThread }TMyBackupThread = class(TThread)privatefStatusText: string;procedure ShowStatus;protectedprocedure Execute; override;publicconstructor Create(CreateSuspended: boolean);end;{ TForm1 }TForm1 = class(TForm) 

然后在实现线程内容

{TBackupThread}procedure TMyBackupThread.ShowStatus;
// this method is only called by Synchronize(@ShowStatus) and therefore
// executed by the main thread
// The main thread can access GUI elements, for example Form1.Caption.
beginwriteln( fStatusText);form1.Memo1.Append(fStatusText);
end;procedure TMyBackupThread.Execute;
varRespo: TStringStream;S: string;
beginfStatusText := 'Backup Starting ...';Synchronize(@Showstatus);  //If I remark this, it causes "access violation" errorwith TFPHttpClient.Create(nil) dotryRespo := TStringStream.Create('');WriteLn(form1.Memo1.Lines.Strings[0]);WriteLn(Formatdatetime('yyyy-mm-dd hh:nn:ss.zzz',now));     FileFormPost(requrl + 'downFile', 'file', form1.Memo1.Lines.Strings[0], Respo);S := Respo.DataString;WriteLn(s);WriteLn(Formatdatetime('yyyy-mm-dd hh:nn:ss.zzz',now));form1.Memo1.Append(S);Respo.Destroy;     finallyFree;end;fStatusText := 'Backup Completed';Synchronize(@Showstatus);MyShowThread.active:=false;Form3.hide;
end;constructor TMyBackupThread.Create(CreateSuspended: boolean);
beginFreeOnTerminate := True;inherited Create(CreateSuspended);
end;                  

然后就可以在主界面里需要的地方调用了

procedure TForm1.btnUpClick(Sender: TObject);
varMyBackupThread : TMyBackupThread;
beginMyBackupThread := TMyBackupThread.Create(True); // With the True parameter it doesn't start automaticallyif Assigned(MyBackupThread.FatalException) thenraise MyBackupThread.FatalException;// Here the code initialises anything required before the threads starts executingif Form3=nil thenbeginForm3:=TForm3.Create(application);WriteLn('TForm3.Create');end;Form3.Show;//Test_DummyMyBackupThread.Start;Form3.FormProgress;
end;   

from3是做了一个动画进度条，也可不要，至少主界面不会卡在那里不动了

lazarus要展示gif动画图片，需要安装gifanim组件，只需要把文件名赋值即可