delphi - 在 firemonkey 移动开发中正确使用 TAniIndicator 等待处理

Question

我正在使用 Delphi XE-5(Firemonkey 移动应用程序)

我正在尝试通过在长时间处理过程中显示来使 TAniIndicator 正常工作。我的主窗体上有一个 TAniIndicator (AniIndi)，但它不旋转。它显示正确，但不旋转。

begin
 Loading:= True;
 AniIndi.Visible:= True;
 AniIndi.Enabled:= True;
 UpdateAll;
 Application.ProcessMessages;

 //do my processsing here

 Loading:= False;
 AniIndi.Enabled:= False;
 AniIndi.Visible:= False;
 UpdateAll;
 Application.ProcessMessages;
end;

//根据雷米的答案进行编辑

TLoadThread = class(TThread)
 public
  Config: Boolean;
  constructor Create(const aConfig: Boolean); reintroduce;
 protected
  procedure DoProcessing;
  procedure Execute; Override;
 end;

var
 loading: Boolean = false;
 zLThread: TLoadThread = nil;

constructor TLoadThread.Create(const aConfig: Boolean);
begin
 inherited Create(true);
 Config:= aConfig;
end;

procedure TLoadThread.DoProcessing;
var
begin
 //do processing here and update main form
end;

procedure TLoadThread.Execute;
begin
 FreeOnTerminate:= true;
 Synchronize(DoProcessing);
end;


procedure TfrmMain.FormActivate(Sender: TObject);
begin
 zLThread:= TLoadThread.Create(True, Host, NamePath, Config, Port);
 zLThread.OnTerminate := ThreadTerminated;
 zLThread.Start;
 Loading := True;
 AniIndi.Visible := True;
 AniIndi.Enabled := True;
 UpdateAll;
end;

procedure TfrmMain.ThreadTerminated(Sender: TObject);
begin
  zLThread := nil;
  Loading := False;
  AniIndi.Enabled := False;
  AniIndi.Visible := False;
  UpdateAll;
end;

Answer 1

当您的长进程运行时，您的主线程需要保持对消息队列的响应。如果没有，您将阻止动画(以及 UI 的其他方面)接收新消息，例如绘制请求和计时器通知。您需要将所有长处理移至单独的线程。启动线程，然后启动动画。同时让主线程正常处理UI。当线程完成时，让它通知主线程，然后主线程可以停止动画，并完成对线程结果所需的任何其他处理(如果有)。例如:

type
  TLoadThread = class(TThread)
  public
    Host: string;
    NamePath: string;
    Port: Integer;
    Config: Boolean;
    constructor Create(const aHost, aNamePath: string; aPort: Integer; aConfig: Boolean); reintroduce;
  protected
    procedure Execute; override;
  end;

constructor TLoadThread.Create(const aHost, aNamePath: string; aPort: Integer; aConfig: Boolean);
begin
  inherited Create(True);
  FreeOnTerminate := True;
  Host := aHost;
  NamePath := aNamePath;
  Port := aPort;
  Config := aConfig;
end;

procedure TLoadThread.Execute;
begin
  //do processing

  Synchronize(
    procedure
      //update main form
    end
  );

  //do processing
end;

var
  Loading: Boolean = False;
  zLThread: TLoadThread = nil;

procedure TfrmMain.FormActivate(Sender: TObject);
begin
  zLThread := TLoadThread.Create(Host, NamePath, Port, Config);
  zLThread.OnTerminate := ThreadTerminated;
  zLThread.Start;
  Loading := True;
  AniIndi.Visible := True;
  AniIndi.Enabled := True;
  UpdateAll;
end;

procedure TfrmMain.ThreadTerminated(Sender: TObject);
begin
  zLThread := nil;
  Loading := False;
  AniIndi.Enabled := False;
  AniIndi.Visible := False;
  UpdateAll;
end;