Question

我希望看到完全初始化的用户界面，标签显示＆＃34;数据未加载＆＃34;，然后5秒后＃34;数据加载＆＃34;。

我从那里做了一个例子：What is the best way to autostart an action after OnShow event?

但是我没有看到任何内容，然后只有＆＃34;数据被加载＆＃34;，在延迟之后。

代码如下：

StartupAction.dpr

program StartupAction;

uses
  Vcl.Forms,
  MainForm in 'MainForm.pas' {Form1};

{$R *.res}

begin
  Application.Initialize;
  Application.MainFormOnTaskbar := True;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

MainForm.dfm

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 254
  ClientWidth = 635
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object lbl1: TLabel
    Left = 104
    Top = 40
    Width = 87
    Height = 13
    Caption = 'Data is not loaded'
  end
end

MainForm.pas

unit MainForm;
//Load data after full UI initialization

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    lbl1: TLabel;
  private const
    WM_STARTUP = WM_USER;
  protected
    procedure DoShow(); override;
  private
    procedure WMStartup(var Msg: TMessage); message WM_STARTUP;
    procedure _loadData();
  public
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.DoShow();
begin
  inherited;
  PostMessage(Handle, WM_STARTUP, 0, 0);
end;

procedure TForm1.WMStartup(var Msg: TMessage);
begin
  inherited;
  _loadData();
end;

procedure TForm1._loadData();
begin
  Sleep(5000);
  lbl1.Caption := 'Data is loaded';
end;

end.

在某种程度上有效的唯一解决方案是使用TTimer，延迟时间为500毫秒，但这不是一个真正的解决方案。

完整UI初始化后加载数据

0 个答案: