去掉 TSpeedButton 上的闪烁效果

Question

复现步骤：

1. 在新的VCL表单中添加TPanel并设置Align = alClient。
2. 将TSpeedButton添加到面板中，并将一些bmp图像分配给Glyph属性。（可选，但使其更清晰：Flat = True）
3. 运行应用程序，抓住窗体的右下角并移动它。 TSpeedButton中的图像会闪烁。

我阅读了很多关于消除闪烁的文章，但建议都似乎对TSpeedButton无效：

• 没有DoubleBuffered属性
• WS_EX_COMPOSITED无法设置，因为它不是TWinControl而是TGraphicControl
• 未收到WM_ERASEBKGND消息

如果这有任何重要性，请注意，我实际上正在使用TPngSpeedButton，但由于实际问题在于TSpeedButton，因此我在示例中使用它。

有没有任何解决方案？

编辑：出于某种原因，迄今为止没有人能够复现这个问题，因此为了确保不是我的描述有问题，这里是dfm：

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 337
  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 Panel1: TPanel
    Left = 0
    Top = 0
    Width = 635
    Height = 337
    Align = alClient
    Caption = 'Panel1'
    TabOrder = 0
    object SpeedButton1: TSpeedButton
      Left = 64
      Top = 56
      Width = 32
      Height = 32
      Flat = True
      Glyph.Data = {
        360C0000424D360C000000000000360000002800000020000000200000000100
        180000000000000C000000000000000000000000000000000000FFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FCC483FCC483FCC483F241CED241CED241CED241CED241CEDCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FCC483FCC483FCC483F241CED241CED241CED241CED241CEDCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FCC483FCC483FCC483F241CED241CED241CED241CED241CEDCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FCC483FCC483FCC483F241CED241CED241CED241CED241CEDCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FCC483FCC483FCC483F241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FFFFFFFFFFFFFFFFFFF241CED241CED241CED241CED241CED241C
        ED241CED241CED241CED241CED241CED241CED241CED241CED241CED241CED24
        1CED241CED241CED241CED241CED241CED241CED241CED241CEDCC483FCC483F
        CC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC483F
        CC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC483F
        CC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC483F
        CC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC483F
        CC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC483F
        CC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCC483FCC483F
        CC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC483FCC48
        3FCC483FCC483FCC483FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
        FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF}
    end
  end
end

这是它的外观。实际上它运行得稍微快一些，但是录制视频和gif转换会使其减速一些。

- CodeX

---

是的，请使用常规的 TButton。无论如何，我无法在 Delphi Tokyo 中重现。 - Victoria

看一下把“transparent”设为false是否有帮助。默认值是true，但如果使用了位图，就不需要它了。 - Sertac Akyuz

在D7和XE7中尝试过，都没有像你所说的那样出现任何闪烁。 （在两次尝试中都使用了.bmp作为图标） - Tom Brunberg

我不明白为什么没有人能够复现它。搜索网络后发现我并不是唯一遇到这个问题的人。我现在已经添加了dfm代码和屏幕截图。我的意思是，我没有编造这个问题。所以即使这个问题只出现在一些系统上，它仍然是一个问题。为什么要投反对票？:( - CodeX

@quasoft：是的，我尝试过为面板和窗体使用DoubleBuffered，但没有成功。 - CodeX

Answer 1

我实际上可以在 Windows 7 上使用 Delphi 10.2.3 Tokyo 复现它。我经常遇到类似的问题，自从那时起，我一直在为所有 TPanel 及其派生类使用这些设置，而这在本例中也起作用了。

Panel1.DoubleBuffered := True;
Panel1.ParentBackground := False;

- Triber

---

哇，Panel1.ParentBackground := False 似乎是关键！设置此属性可以消除闪烁（无论 Panel1.DoubleBuffered 值如何）。这是什么魔法？我尝试了很多次，但没想到也要尝试这个。非常感谢！ - CodeX

我的复现中两者都是必需的。 - Sertac Akyuz