Delphi 2010 TButtonGroup控件的使用

TButtonGroup显示在一个容器中的按钮组。使用TButtonGroup可以创建相关按钮集合。下面来学习使用这个控件，拖动Tool Palette面板的Additional类别下TButtonGroup控件到窗体上，控件截图如下所示：



动态设置此控件属性和添加按钮项代码如下所示：

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procedure TForm1.FormCreate(Sender: TObject); begin with btn1 do begin BorderStyle := bsNone; ButtonHeight := 48; ButtonWidth := 48; ButtonOptions := [gboAllowReorder, //允许用户在运行时可拖动按钮改变顺序 gboFullSize, //设置组中按钮的最大宽度，整个容器的宽度 gboGroupStyle, //按钮应该继承容器组风格 gboShowCaptions]; //在项中的按钮显示Captions标题 Images := il1; //绑定 TImageList ShowHint := True; //可以显示Hint with Items.Add do begin Caption := '按钮一'; Hint := '这是按钮一'; ImageIndex := 0; end; with Items.Add do begin Caption := '按钮二'; Hint := '这是按钮二'; ImageIndex := 1; end; ItemIndex := 0; end; end;

效果如下图所示：



会不会想要修改按钮显示颜色、显示的效果等等，TButtonGroup并没有开放颜色属性，我们只有重载其DrawButton函数，跟踪其源码，发现可以将其绘制函数复制过来，改为自己想要显示的效果即可，如下代码所示：

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unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ButtonGroup, ImgList, CategoryButtons; type TForm1 = class(TForm) btn1: TButtonGroup; il1: TImageList; procedure FormCreate(Sender: TObject); procedure btn1DrawButton(Sender: TObject; Index: Integer; Canvas: TCanvas; Rect: TRect; State: TButtonDrawState); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} uses GraphUtil; procedure TForm1.btn1DrawButton(Sender: TObject; Index: Integer; Canvas: TCanvas; Rect: TRect; State: TButtonDrawState); var TextLeft, TextTop: Integer; RectHeight: Integer; ImgTop: Integer; TextOffset: Integer; ButtonItem: TGrpButtonItem; FillColor: TColor; EdgeColor: TColor; InsertIndication: TRect; TextRect: TRect; OrgRect: TRect; Text: string; begin OrgRect := Rect; //------------------在这里修改了显示颜色--------------------- Canvas.Font := (Sender as TButtonGroup).Font; if bdsSelected in State then begin Canvas.Brush.Color := GetShadowColor(RGB(254,202,115), -25); Canvas.Font.Color := RGB(108,72,2); end else if bdsDown in State then begin Canvas.Brush.Color := RGB(254,202,115); Canvas.Font.Color := RGB(108,72,2); end else begin Canvas.Brush.Color := RGB(196,218,241); Canvas.Font.Color := RGB(43,53,77); end; {if Assigned(FOnBeforeDrawButton) then //在这里可以添加调用OnBeforeDrawButton FOnBeforeDrawButton(Self, Index, Canvas, Rect, State);} FillColor := Canvas.Brush.Color; EdgeColor := GetShadowColor(FillColor, -25); Canvas.FillRect(Rect); InflateRect(Rect, -2, -1); if (bdsHot in State) and not (bdsDown in State) then EdgeColor := GetShadowColor(EdgeColor, -50); { Draw the edge outline } Canvas.Brush.Color := EdgeColor; Canvas.FrameRect(Rect); Canvas.Brush.Color := FillColor; { Compute the text location } TextLeft := Rect.Left + 4; RectHeight := Rect.Bottom - Rect.Top; TextTop := Rect.Top + (RectHeight - Canvas.TextHeight('Wg')) div 2; { Do not localize } if TextTop < Rect.Top then TextTop := Rect.Top; if bdsDown in State then begin Inc(TextTop); Inc(TextLeft); end; ButtonItem := (Sender as TButtonGroup).Items[Index]; { Draw the icon - prefer the event } TextOffset := 0; {if Assigned(FOnDrawIcon) then //在这里可以添加调用OnDrawIcon FOnDrawIcon(Self, Index, Canvas, OrgRect, State, TextOffset) else }if ((Sender as TButtonGroup).Images <> nil) and (ButtonItem.ImageIndex > -1) and (ButtonItem.ImageIndex < (Sender as TButtonGroup).Images.Count) then begin ImgTop := Rect.Top + (RectHeight - (Sender as TButtonGroup).Images.Height) div 2; if ImgTop < Rect.Top then ImgTop := Rect.Top; if bdsDown in State then Inc(ImgTop); (Sender as TButtonGroup).Images.Draw(Canvas, TextLeft - 1, ImgTop, ButtonItem.ImageIndex); TextOffset := (Sender as TButtonGroup).Images.Width + 1; end; { Show insert indications } if [bdsInsertLeft, bdsInsertTop, bdsInsertRight, bdsInsertBottom] * State <> [] then begin Canvas.Brush.Color := GetShadowColor(EdgeColor); InsertIndication := Rect; if bdsInsertLeft in State then begin Dec(InsertIndication.Left, 2); InsertIndication.Right := InsertIndication.Left + 2; end else if bdsInsertTop in State then begin Dec(InsertIndication.Top); InsertIndication.Bottom := InsertIndication.Top + 2; end else if bdsInsertRight in State then begin Inc(InsertIndication.Right, 2); InsertIndication.Left := InsertIndication.Right - 2; end else if bdsInsertBottom in State then begin Inc(InsertIndication.Bottom); InsertIndication.Top := InsertIndication.Bottom - 2; end; Canvas.FillRect(InsertIndication); Canvas.Brush.Color := FillColor; end; if gboShowCaptions in (Sender as TButtonGroup).ButtonOptions then begin { Avoid clipping the image } Inc(TextLeft, TextOffset); TextRect.Left := TextLeft; TextRect.Right := Rect.Right - 1; TextRect.Top := TextTop; TextRect.Bottom := Rect.Bottom -1; Text := ButtonItem.Caption; Canvas.TextRect(TextRect, Text, [tfEndEllipsis]); end; if bdsFocused in State then begin { Draw the focus rect } InflateRect(Rect, -2, -2); Canvas.DrawFocusRect(Rect); end; {if Assigned(FOnAfterDrawButton) then //在这里可以添加调用OnAfterDrawButton FOnAfterDrawButton(Self, Index, Canvas, OrgRect, State); } end;

运行效果如下图所示：



看了DrawButton源码，可以知道，我们也可以添加OnBeforeDrawButton事件，即可快速改变TButtonGroup的显示颜色，代码如下所示：

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procedure TForm1.btn1BeforeDrawButton(Sender: TObject; Index: Integer; Canvas: TCanvas; Rect: TRect; State: TButtonDrawState); begin if bdsSelected in State then begin Canvas.Brush.Color := GetShadowColor(RGB(254,202,115), -25); Canvas.Font.Color := RGB(108,72,2); end else if bdsDown in State then begin Canvas.Brush.Color := RGB(254,202,115); Canvas.Font.Color := RGB(108,72,2); end else begin Canvas.Brush.Color := RGB(196,218,241); Canvas.Font.Color := RGB(43,53,77); end; end;

扩展资料：

1.VCL Controls: Button Groups http://www.functionx.com/cppbuilder/controls/buttongroup.htm
2.This example demonstrates how to use a TButtonGroup. http://docwiki.embarcadero.com/CodeExamples/XE2/en/VCLButtons%28Delphi%29