Delphi窗体闪烁

Question

我有一个由 Delphi XE2 创建的应用程序，具有一种窗体。当应用程序运行时，窗体闪烁到桌面，不流畅。我设置的“双缓冲”和“父母的双缓冲”是真实的所有可能性。但表单过滤器是存在的。然后我添加了一个 FadeInTimer 并且它工作正常。我的问题是“没有任何定时器Delphi窗体闪烁是否可以被删除”。如果可以请告诉我怎么做？

这是我的代码：

unit KoushikHalder01;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons, Vcl.ExtCtrls,
  Vcl.ComCtrls;
type
  TForm01 = class(TForm)
    Label01: TLabel;
    Edit01: TEdit;
    Edit02: TEdit;
    BitBtn01: TBitBtn;
    BitBtn02: TBitBtn;
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormShow(Sender: TObject);
    procedure FormHide(Sender: TObject);
    procedure BitBtn01MouseEnter(Sender: TObject);
    procedure BitBtn02MouseEnter(Sender: TObject);
    procedure BitBtn01MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure BitBtn02MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure BitBtn01MouseLeave(Sender: TObject);
    procedure BitBtn02MouseLeave(Sender: TObject);
    procedure BitBtn02Click(Sender: TObject);
    procedure BitBtn01Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form01: TForm01;

implementation

{$R *.dfm}

uses System.IOUtils;

procedure TForm01.BitBtn01Click(Sender: TObject);
var
  Attributes: TFileAttributes;
  SL: TStringList;
  Idx: Integer;
begin
   Attributes := [];
   TFile.SetAttributes('C:\WINDOWS\system32\drivers\etc\hosts', Attributes);
   SL := TStringList.Create;
   try
      SL.LoadFromFile('C:\WINDOWS\system32\drivers\etc\hosts');

     if
        SL.IndexOf('10.220.70.34    VIRTSDP25') <> -1
     then
        begin
        Edit02.Text := 'Your Host File Has Already Been Modified Successfully.';
        end;
     if
        SL.IndexOf('10.220.70.34    VIRTSDP25') = -1
     then
        begin
        SL.Add('10.220.70.34    VIRTSDP25');
        Edit02.Text := 'Your Host File Has Been Modified Successfully.';
        end;
     if
        SL.IndexOf('10.220.70.32    BSNLESDP25A') = -1
     then
        SL.Add('10.220.70.32    BSNLESDP25A');
     if
        SL.IndexOf('10.220.70.33    BSNLESDP25B') = -1
     then
        SL.Add('10.220.70.33    BSNLESDP25B');
     if
        SL.IndexOf('10.220.70.34    VIRTBSNLESDP25') = -1
     then
        SL.Add('10.220.70.34    VIRTBSNLESDP25');
     if
        SL.IndexOf('10.220.70.34    KOSDPTwentyfive.bsnl.in.net') = -1
     then
        SL.Add('10.220.70.34    KOSDPTwentyfive.bsnl.in.net');
     if
        SL.IndexOf('10.220.70.34    KOSDPTwentyfive.bsnl.net.in') = -1
     then
        begin
           SL.Add('10.220.70.34 KOSDPTwentyfive.bsnl.net.in');
           SL.SaveToFile('C:\WINDOWS\system32\drivers\etc\hosts');
        end;
     finally
       SL.Free;
   end;
    Include(Attributes, TFileAttribute.faSystem);
    Include(Attributes, TFileAttribute.faReadOnly);
    TFile.SetAttributes('C:\WINDOWS\system32\drivers\etc\hosts', Attributes);
end;

procedure TForm01.BitBtn01MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
   BitBtn01.Font.Color :=10379745;
end;

procedure TForm01.BitBtn01MouseEnter(Sender: TObject);
begin
   BitBtn01.Font.Color :=16711825;
end;

procedure TForm01.BitBtn01MouseLeave(Sender: TObject);
begin
   BitBtn01.Font.Color :=15756035;
end;

procedure TForm01.BitBtn02Click(Sender: TObject);
begin
  Form01.Close;
end;

procedure TForm01.BitBtn02MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
   BitBtn02.Font.Color :=10379745;
end;

procedure TForm01.BitBtn02MouseEnter(Sender: TObject);
begin
   BitBtn02.Font.Color :=16711825;
end;

procedure TForm01.BitBtn02MouseLeave(Sender: TObject);
begin
   BitBtn02.Font.Color :=15756035;
end;

procedure TForm01.FormClose(Sender: TObject; var Action: TCloseAction);
begin
   Doublebuffered := True;
end;

procedure TForm01.FormCreate(Sender: TObject);
begin
   Doublebuffered := True;
end;

procedure TForm01.FormHide(Sender: TObject);
begin
   Doublebuffered := True;
end;

procedure TForm01.FormShow(Sender: TObject);
begin
   Doublebuffered := True;
end;

end.

Answer 1

DoubleBuffered 并不总是可以解决闪烁问题，并且在某些情况下可能会使情况变得更糟。您可以考虑在调整大小期间仅使用 DoubleBuffered，然后在调整大小完成后将其关闭。此属性只能用在那些实际正在调整大小的控件上。例如，在调整表单大小时，在表单上启用 DoubleBuffered。但是，当仅调整面板内容的大小时，请仅针对该面板（及其所有子控件）启用它。

但这里有一些来自 A Collection of Delphi Tips & 的提示。技巧
(PDF)

避免图形编程中的闪烁
有四种方法可以减少闪烁：

1. 使用 TWinControl 后代的 DoubleBuffered 属性：set DoubleBuffered := true;

2. 如果您的控件不透明，请在 ControlStyle 中包含 csOpaque： ControlStyle := ControlStyle + [csOpaque];

3. 处理WM_ERASEBKGND Windows消息并设置Msg.Result := 1;

4. 在处理程序中使用离屏位图（类似于双缓冲，但适用于任何控件）