如何自定义TcxPageControl中pcoGoDialog弹出菜单的选中颜色？

解决方案 #

要修改TcxPageControl的GoDialog弹出菜单选中颜色，需要拦截该内部弹出菜单的绘制事件，自定义选中项的背景和文字颜色。以下是具体实现步骤：

1. 子类化TcxPageControl，重写菜单创建方法
   重写CreateGoDialogMenu方法，获取内部生成的弹出菜单实例，并绑定自定义绘制事件。
2. 实现自定义菜单绘制事件
   在绘制事件中判断菜单项的选中状态，替换默认的蓝色高亮为自定义颜色。

修改后的完整代码 #

unit Unit2;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, dxBarBuiltInMenu, cxGraphics,
  cxControls, cxLookAndFeels, cxLookAndFeelPainters, dxSkinsCore, dxSkinBasic,
  cxPC, cxPCPainters, cxPCPaintersFactory, dxBarMenus, dxBar;

const
  MyStyleId = 100;

type
  // 子类化TcxPageControl以拦截GoDialog菜单创建
  TMycxPageControl = class(TcxPageControl)
  protected
    function CreateGoDialogMenu: TdxBarPopupMenu; override;
  end;

  TForm2 = class(TForm)
    cxPageControl1: TMycxPageControl; // 注意这里类改为TMycxPageControl
    cxTabSheet1: TcxTabSheet;
    cxTabSheet2: TcxTabSheet;
    cxTabSheet3: TcxTabSheet;
    cxTabSheet4: TcxTabSheet;
    cxTabSheet5: TcxTabSheet;
    cxTabSheet6: TcxTabSheet;
    cxTabSheet7: TcxTabSheet;
    procedure FormCreate(Sender: TObject);
    procedure cxPageControl1DrawTabEx(AControl: TcxCustomTabControl;
      ATab: TcxTab; Font: TFont);
  private
    procedure MyPopupMenuDrawItem(Sender: TObject; ACanvas: TCanvas;
      AItem: TdxBarItem; AItemRect: TRect; AState: TdxBarItemState);
  public
  end;

  TMyPCPainter = class(TcxPCUltraFlatPainter)
  private
    class function GetStyleID: TcxPCStyleID; static;
  protected
    function GetTabsRowColor: TColor; override;
    function GetTabCorrection(ATabVisibleIndex: Integer): TRect; override;
    function GetButtonColor(AButtonState: TcxPCNavigatorButtonState): TColor; override;
  public
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

{ TMycxPageControl }

function TMycxPageControl.CreateGoDialogMenu: TdxBarPopupMenu;
begin
  Result := inherited CreateGoDialogMenu;
  // 绑定自定义绘制事件
  Result.OnDrawItem := Form2.MyPopupMenuDrawItem;
end;

{ TMyPCPainter }

function TMyPCPainter.GetButtonColor(AButtonState: TcxPCNavigatorButtonState): TColor;
begin
  Result := clGray;
end;

class function TMyPCPainter.GetStyleID: TcxPCStyleID;
begin
  Result := MyStyleId;
end;

function TMyPCPainter.GetTabCorrection(ATabVisibleIndex: Integer): TRect;
begin
  // 增加标签间距
  Result := Rect(5, -1, 0, 2);
end;

function TMyPCPainter.GetTabsRowColor: TColor;
begin
  Result := clGray;
end;

{ TForm2 }

procedure TForm2.cxPageControl1DrawTabEx(AControl: TcxCustomTabControl;
  ATab: TcxTab; Font: TFont);
begin
  if ATab.IsMainTab then
  begin
    ATab.Color := clWhite;
    Font.Color := clBlack;
  end
  else
  begin
    ATab.Color := clBlack;
    Font.Color := clWhite;
  end;
end;

procedure TForm2.FormCreate(Sender: TObject);
begin
  cxPageControl1.Style := MyStyleId;
  cxPageControl1.OnDrawTabEx := cxPageControl1DrawTabEx;
end;

procedure TForm2.MyPopupMenuDrawItem(Sender: TObject; ACanvas: TCanvas;
  AItem: TdxBarItem; AItemRect: TRect; AState: TdxBarItemState);
var
  LTextRect: TRect;
begin
  // 绘制默认背景
  ACanvas.Brush.Color := clWindow;
  ACanvas.FillRect(AItemRect);

  // 判断是否为选中状态（鼠标悬停或选中）
  if bisSelected in AState then
  begin
    // 设置自定义选中背景色（这里用clMaroon，可替换为你需要的颜色）
    ACanvas.Brush.Color := clMaroon;
    ACanvas.FillRect(AItemRect);
    // 设置选中时的文字颜色
    ACanvas.Font.Color := clWhite;
  end
  else
  begin
    // 默认文字颜色
    ACanvas.Font.Color := clWindowText;
  end;

  // 绘制菜单项文本
  LTextRect := AItemRect;
  InflateRect(LTextRect, -2, 0); // 调整文本边距
  DrawText(ACanvas.Handle, PChar(AItem.Caption), Length(AItem.Caption), LTextRect,
    DT_LEFT or DT_VCENTER or DT_SINGLELINE);
end;

initialization
  RegisterPCPainterClass(TMyPCPainter);

finalization
  UnregisterPCPainterClass(TMyPCPainter);

end.

注意事项 #

1. 修改DFM文件：如果是在设计时添加的TcxPageControl，需要打开DFM文件（右键窗体 -> View as Text），将object cxPageControl1: TcxPageControl改为object cxPageControl1: TMycxPageControl，否则运行时会报错。
2. 自定义颜色：代码中clMaroon是示例选中背景色，你可以替换为任意TColor值（比如clGreen、$00FFCC99等）。
3. 图标处理：如果菜单项包含图标，需要在MyPopupMenuDrawItem中添加图标绘制逻辑，可参考DevExpress的默认绘制代码实现。

内容的提问来源于stack exchange，提问作者DelphiLearner