delphi - TPageControl 有很多选项卡时闪烁

Question

我的问题是我有一个 TPageControl，其中包含动态创建的多个选项卡，每个选项卡包含一个 (alClient) TMemo。当选项卡数量超过控件的宽度并且滚动箭头出现在选项卡标题上时，我的所有(以及大量)控件开始频繁闪烁。仅当滚动到其停止的 TPageControl View 之外且页面控件可见时才会发生此闪烁。当调整页面控件的大小以便不再需要滚动箭头来查看所有选项卡时，闪烁就会停止。

我相当确信问题是由滚动箭头引起的，导致发生一些绘画，因为当我将 TPageControl.MultiLine 设置为 true 时，就没有闪烁了。理想情况下，我不想使用 MultiLine 选项卡并希望有人可以提供解决方案。

有关表单布局的信息

我有一个(个人详细信息)表单，其中包含许多 TSpeedButtons、TLabels、TEdits、一个 TImage等等。其中许多元素都位于 TScrollBox 内部，并使用 TPanels 将其分组为多个部分。面板在滚动框中设置为 alTop，并将 autosize 设置为 true，但它们的高度永远不会改变。

我尝试将所有控件设置为尽可能将 DoubleBuffered 设置为 true 并将 ParentBackground/Color = false 设置为 true，但遗憾的是没有任何效果。

在添加 PageControls 并使用 David 的快速破解答案之前，我遇到了闪烁问题 TLabel and TGroupbox Captions Flicker on Resize我能够改善调整表单大小时的闪烁问题。通过扩展 TLabel 并从 Paint 过程中删除背景清除(按照其他地方的建议)，我能够 99% 地消除滚动 ScrollBox 时闪烁的标签，但现在我遇到了一个新的闪烁问题。

---编辑---

这里是我的表单的精简版本的链接，其中出现闪烁 flickering example

人员.DetailsForm.pas

unit Personnel.DetailsForm;

interface

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls, System.Actions,
    Vcl.ActnList, Vcl.Buttons, Vcl.StdCtrls, Vcl.ComCtrls, Vcl.WinXCtrls, Vcl.Imaging.jpeg;

type
    TPersonnelDetailsForm = class(TForm)
        ScrollBox_Content: TScrollBox;
        panel_AddressDetails: TPanel;
        gpanel_Address: TGridPanel;
        edit_HomeMobilePhone: TEdit;
        edit_HomeTown: TEdit;
        edit_HomeStreet: TEdit;
        edit_HomePhone: TEdit;
        lbl_HomeStreet: TLabel;
        lbl_HomePhone: TLabel;
        lbl_MobilePhone: TLabel;
        lbl_HomeTown: TLabel;
        edit_HomeState: TEdit;
        edit_HomeEmail: TEdit;
        edit_HomeCountry: TEdit;
        edit_HomeFax: TEdit;
        lbl_HomeState: TLabel;
        lbl_Fax: TLabel;
        lbl_Email: TLabel;
        lbl_HomeCountry: TLabel;
        edit_HomePostCode: TEdit;
        lbl_HomePostCode: TLabel;
        panel_HomeAddressTitle: TPanel;
        panel_GeneralNotesDetails: TPanel;
        gpanel_GeneralNotesDetails_: TGridPanel;
        pageControl_GeneralNotes: TPageControl;
        procedure FormClose(Sender: TObject; var Action: TCloseAction);
        procedure FormShow(Sender: TObject);
        procedure FormMouseWheel(Sender: TObject; Shift: TShiftState; WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
    private
        { Private declarations }
    public
        { Public declarations }
    end;

var
    PersonnelDetailsForm: TPersonnelDetailsForm;

implementation

{$R *.dfm}

uses
    System.Math,
    System.DateUtils,
    System.Threading,
    System.RegularExpressions,
    System.StrUtils,
    System.Contnrs,
    System.UITypes,
    System.Types,

    Winapi.Shellapi,

    Vcl.ExtDlgs;

procedure EnableComposited(WinControl: TWinControl);
var
    i: Integer;
    NewExStyle: DWORD;
begin
    NewExStyle := GetWindowLong(WinControl.Handle, GWL_EXSTYLE) or WS_EX_COMPOSITED;
    SetWindowLong(WinControl.Handle, GWL_EXSTYLE, NewExStyle);

    for i := 0 to WinControl.ControlCount - 1 do
        if WinControl.Controls[i] is TWinControl then
            EnableComposited(TWinControl(WinControl.Controls[i]));
end;

procedure TPersonnelDetailsForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
    // Close the form and make sure it frees itself
    Action := caFree; // Should allow it to free itself on close
    self.Release; // Sends a Release message to itself as backup
end;

procedure TPersonnelDetailsForm.FormMouseWheel(Sender: TObject; Shift: TShiftState; WheelDelta: Integer; MousePos: TPoint;
    var Handled: Boolean);
var
    LTopLeft, LTopRight, LBottomLeft, LBottomRight: Integer;
    LPoint: TPoint;
begin
    Handled := true;

    // First you have to get the position of the control on screen
    // as MousePos coordinates are based on the screen positions.
    LPoint := self.ScrollBox_Content.ClientToScreen(Point(0, 0));
    LTopLeft := LPoint.X;
    LTopRight := LTopLeft + self.ScrollBox_Content.Width;
    LBottomLeft := LPoint.Y;
    LBottomRight := LBottomLeft + self.ScrollBox_Content.Width;

    if (MousePos.X >= LTopLeft) and (MousePos.X <= LTopRight) and (MousePos.Y >= LBottomLeft) and (MousePos.Y <= LBottomRight) then
    begin
        // If the mouse is inside the scrollbox coordinates,
        // scroll it by setting .VertScrollBar.Position.
        self.ScrollBox_Content.VertScrollBar.Position := self.ScrollBox_Content.VertScrollBar.Position - WheelDelta;
        Handled := true;
    end;

    if FindVCLWindow(MousePos) is TComboBox then
        Handled := true;
end;

procedure TPersonnelDetailsForm.FormShow(Sender: TObject);
var
    memo: TMemo;
    tabsheet: TTabSheet;
    ii: Integer;
begin
    for ii := 0 to 7 do
    begin
        memo := TMemo.Create(self);
        memo.Align := TAlign.alClient;
        memo.ReadOnly := true;
        memo.ScrollBars := TScrollStyle.ssVertical;
        memo.ParentColor := false;

        tabsheet := TTabSheet.Create(self);
        tabsheet.InsertControl(memo);
        tabsheet.PageControl := self.pageControl_GeneralNotes;
        tabsheet.Caption := 'A New TabSheet ' + IntToStr(ii);
        tabsheet.Tag := ii;

        memo.Text := 'A New Memo ' + IntToStr(ii);
    end;

    EnableComposited(self);

    self.ScrollBox_Content.ScrollInView(self.panel_AddressDetails);
    self.Invalidate;
end;

end.   

人员.DetailsForm.dfm

object PersonnelDetailsForm: TPersonnelDetailsForm
  Left = 0
  Top = 0
  Caption = 'Personnel Details Form'
  ClientHeight = 371
  ClientWidth = 800
  Color = clBtnFace
  DoubleBuffered = True
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -13
  Font.Name = 'Segoe UI'
  Font.Style = []
  OldCreateOrder = False
  OnClose = FormClose
  OnMouseWheel = FormMouseWheel
  OnShow = FormShow
  PixelsPerInch = 96
  TextHeight = 17
  object ScrollBox_Content: TScrollBox
    Left = 0
    Top = 0
    Width = 800
    Height = 371
    VertScrollBar.Smooth = True
    VertScrollBar.Tracking = True
    Align = alClient
    TabOrder = 0
    object panel_AddressDetails: TPanel
      Tag = 101
      Left = 0
      Top = 0
      Width = 796
      Height = 174
      Align = alTop
      Padding.Left = 5
      Padding.Top = 5
      Padding.Right = 5
      Padding.Bottom = 5
      ParentBackground = False
      TabOrder = 0
      object gpanel_Address: TGridPanel
        Left = 6
        Top = 30
        Width = 784
        Height = 138
        Align = alClient
        BevelOuter = bvNone
        ColumnCollection = <
          item
            SizeStyle = ssAbsolute
            Value = 105.000000000000000000
          end
          item
            Value = 50.000762951094850000
          end
          item
            SizeStyle = ssAbsolute
            Value = 105.000000000000000000
          end
          item
            Value = 49.999237048905160000
          end>
        ControlCollection = <
          item
            Column = 3
            Control = edit_HomeMobilePhone
            Row = 1
          end
          item
            Column = 1
            Control = edit_HomeTown
            Row = 1
          end
          item
            Column = 1
            Control = edit_HomeStreet
            Row = 0
          end
          item
            Column = 3
            Control = edit_HomePhone
            Row = 0
          end
          item
            Column = 0
            Control = lbl_HomeStreet
            Row = 0
          end
          item
            Column = 2
            Control = lbl_HomePhone
            Row = 0
          end
          item
            Column = 2
            Control = lbl_MobilePhone
            Row = 1
          end
          item
            Column = 0
            Control = lbl_HomeTown
            Row = 1
          end
          item
            Column = 1
            Control = edit_HomeState
            Row = 2
          end
          item
            Column = 3
            Control = edit_HomeEmail
            Row = 2
          end
          item
            Column = 1
            Control = edit_HomeCountry
            Row = 3
          end
          item
            Column = 3
            Control = edit_HomeFax
            Row = 3
          end
          item
            Column = 0
            Control = lbl_HomeState
            Row = 2
          end
          item
            Column = 2
            Control = lbl_Fax
            Row = 3
          end
          item
            Column = 2
            Control = lbl_Email
            Row = 2
          end
          item
            Column = 0
            Control = lbl_HomeCountry
            Row = 3
          end
          item
            Column = 1
            Control = edit_HomePostCode
            Row = 4
          end
          item
            Column = 0
            Control = lbl_HomePostCode
            Row = 4
          end>
        Padding.Left = 1
        Padding.Top = 1
        Padding.Right = 1
        Padding.Bottom = 1
        RowCollection = <
          item
            SizeStyle = ssAbsolute
            Value = 27.000000000000000000
          end
          item
            SizeStyle = ssAbsolute
            Value = 27.000000000000000000
          end
          item
            SizeStyle = ssAbsolute
            Value = 27.000000000000000000
          end
          item
            SizeStyle = ssAbsolute
            Value = 27.000000000000000000
          end
          item
            SizeStyle = ssAbsolute
            Value = 27.000000000000000000
          end>
        TabOrder = 0
        object edit_HomeMobilePhone: TEdit
          Left = 498
          Top = 29
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 6
          Text = 'Mobile Phone'
        end
        object edit_HomeTown: TEdit
          Left = 107
          Top = 29
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 1
          Text = 'Home Town'
        end
        object edit_HomeStreet: TEdit
          Left = 107
          Top = 2
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 0
          Text = 'Home Street'
        end
        object edit_HomePhone: TEdit
          Left = 498
          Top = 2
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 5
          Text = 'Home Phone'
        end
        object lbl_HomeStreet: TLabel
          Left = 2
          Top = 2
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Street: '
          Color = clBtnFace
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentColor = False
          ParentFont = False
          Transparent = True
          Layout = tlCenter
          ExplicitLeft = 61
          ExplicitWidth = 44
          ExplicitHeight = 17
        end
        object lbl_HomePhone: TLabel
          Left = 393
          Top = 2
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Home Phone: '
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentFont = False
          Layout = tlCenter
          ExplicitLeft = 408
          ExplicitWidth = 88
          ExplicitHeight = 17
        end
        object lbl_MobilePhone: TLabel
          Left = 393
          Top = 29
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Mobile Phone: '
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentFont = False
          Layout = tlCenter
          ExplicitLeft = 402
          ExplicitWidth = 94
          ExplicitHeight = 17
        end
        object lbl_HomeTown: TLabel
          Left = 2
          Top = 29
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Town: '
          Color = clBtnFace
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentColor = False
          ParentFont = False
          Transparent = True
          Layout = tlCenter
          ExplicitLeft = 64
          ExplicitWidth = 41
          ExplicitHeight = 17
        end
        object edit_HomeState: TEdit
          Left = 107
          Top = 56
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 2
          Text = 'Home State'
        end
        object edit_HomeEmail: TEdit
          Left = 498
          Top = 56
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 7
          Text = 'Home Email'
        end
        object edit_HomeCountry: TEdit
          Left = 107
          Top = 83
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 3
          Text = 'Home Country'
        end
        object edit_HomeFax: TEdit
          Left = 498
          Top = 83
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 8
          Text = 'Home Fax'
        end
        object lbl_HomeState: TLabel
          Left = 2
          Top = 56
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'State: '
          Color = clBtnFace
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentColor = False
          ParentFont = False
          Transparent = True
          Layout = tlCenter
          ExplicitLeft = 66
          ExplicitWidth = 39
          ExplicitHeight = 17
        end
        object lbl_Fax: TLabel
          Left = 393
          Top = 83
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Fax: '
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentFont = False
          Layout = tlCenter
          ExplicitLeft = 467
          ExplicitWidth = 29
          ExplicitHeight = 17
        end
        object lbl_Email: TLabel
          Left = 393
          Top = 56
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Email: '
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentFont = False
          Layout = tlCenter
          ExplicitLeft = 454
          ExplicitWidth = 42
          ExplicitHeight = 17
        end
        object lbl_HomeCountry: TLabel
          Left = 2
          Top = 83
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Country: '
          Color = clBtnFace
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentColor = False
          ParentFont = False
          Transparent = True
          Layout = tlCenter
          ExplicitLeft = 47
          ExplicitWidth = 58
          ExplicitHeight = 17
        end
        object edit_HomePostCode: TEdit
          Left = 107
          Top = 110
          Width = 284
          Height = 25
          Align = alClient
          BevelInner = bvNone
          BevelOuter = bvNone
          TabOrder = 4
          Text = 'Home Post Code'
        end
        object lbl_HomePostCode: TLabel
          Left = 2
          Top = 110
          Width = 103
          Height = 25
          Align = alClient
          Alignment = taRightJustify
          Caption = 'Post Code: '
          Color = clBtnFace
          Font.Charset = DEFAULT_CHARSET
          Font.Color = clWindowText
          Font.Height = -13
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentColor = False
          ParentFont = False
          Transparent = True
          Layout = tlCenter
          ExplicitLeft = 35
          ExplicitWidth = 70
          ExplicitHeight = 17
        end
      end
      object panel_HomeAddressTitle: TPanel
        Left = 6
        Top = 6
        Width = 784
        Height = 24
        Align = alTop
        Alignment = taLeftJustify
        BevelOuter = bvNone
        Caption = ' Home Address '
        Color = clMedGray
        Font.Charset = DEFAULT_CHARSET
        Font.Color = clWindowText
        Font.Height = -13
        Font.Name = 'Segoe UI'
        Font.Style = [fsBold, fsUnderline]
        ParentBackground = False
        ParentFont = False
        TabOrder = 1
      end
    end
    object panel_GeneralNotesDetails: TPanel
      Tag = 303
      Left = 0
      Top = 174
      Width = 796
      Height = 172
      Align = alTop
      AutoSize = True
      Padding.Left = 5
      Padding.Top = 5
      Padding.Right = 5
      Padding.Bottom = 5
      ParentBackground = False
      TabOrder = 1
      object gpanel_GeneralNotesDetails_: TGridPanel
        Left = 6
        Top = 6
        Width = 784
        Height = 160
        Align = alTop
        BevelOuter = bvNone
        ColumnCollection = <
          item
            Value = 100.000000000000000000
          end>
        ControlCollection = <
          item
            Column = 0
            Control = pageControl_GeneralNotes
            Row = 0
          end>
        Padding.Left = 1
        Padding.Top = 1
        Padding.Right = 1
        Padding.Bottom = 1
        RowCollection = <
          item
            SizeStyle = ssAbsolute
            Value = 160.000000000000000000
          end>
        TabOrder = 0
        object pageControl_GeneralNotes: TPageControl
          Left = 2
          Top = 2
          Width = 780
          Height = 158
          Align = alClient
          TabOrder = 0
        end
      end
    end
  end
end

Answer 1

我发现问题是由 quick hack David 引起的回复TLabel and TGroupbox Captions Flicker on Resize当我删除了 TPageControl 选项卡滚动按钮可见时的疯狂闪烁消失了。所以现在我必须看看他更深入的解决方案，看看这是否可以帮助解决我之前看到的一些闪烁问题。