我使用了本示例中提供的代码如何为 TPageControl 的 TTabsheet 实现关闭按钮为页面控件的每个选项卡表绘制一个关闭按钮,并且我在代码内和应用样式时将 ThemeServices 替换为样式服务关闭按钮不显示并且没有任何反应。谁能指出我解决这个问题的不同路径。谢谢你!这是 OnDrawTab 事件的代码:
procedure TFormMain.PageControlCloseButtonDrawTab(Control: TCustomTabControl;
TabIndex: Integer; const Rect: TRect; Active: Boolean);
var
CloseBtnSize: Integer;
PageControl: TPageControl;
TabCaption: TPoint;
CloseBtnRect: TRect;
CloseBtnDrawState: Cardinal;
CloseBtnDrawDetails: TThemedElementDetails;
begin
PageControl := Control as TPageControl;
if InRange(TabIndex, 0, Length(FCloseButtonsRect) - 1) then
begin
CloseBtnSize := 14;
TabCaption.Y := Rect.Top + 3;
if Active then
begin
CloseBtnRect.Top := Rect.Top + 4;
CloseBtnRect.Right := Rect.Right - 5;
TabCaption.X := Rect.Left + 6;
end
else
begin
CloseBtnRect.Top := Rect.Top + 3;
CloseBtnRect.Right := Rect.Right - 5;
TabCaption.X := Rect.Left + 3;
end;
CloseBtnRect.Bottom := CloseBtnRect.Top + CloseBtnSize;
CloseBtnRect.Left := CloseBtnRect.Right - CloseBtnSize;
FCloseButtonsRect[TabIndex] := CloseBtnRect;
PageControl.Canvas.FillRect(Rect);
PageControl.Canvas.TextOut(TabCaption.X, TabCaption.Y, PageControl.Pages[TabIndex].Caption);
if not UseThemes then
begin
if (FCloseButtonMouseDownIndex = TabIndex) and FCloseButtonShowPushed then
CloseBtnDrawState := DFCS_CAPTIONCLOSE + DFCS_PUSHED
else
CloseBtnDrawState := DFCS_CAPTIONCLOSE;
Winapi.Windows.DrawFrameControl(PageControl.Canvas.Handle,
FCloseButtonsRect[TabIndex], DFC_CAPTION, CloseBtnDrawState);
end
else
begin
Dec(FCloseButtonsRect[TabIndex].Left);
if (FCloseButtonMouseDownIndex = TabIndex) and FCloseButtonShowPushed then
CloseBtnDrawDetails := StyleServices.GetElementDetails(twCloseButtonPushed)
else
CloseBtnDrawDetails := StyleServices.GetElementDetails(twCloseButtonNormal);
StyleServices.DrawElement(PageControl.Canvas.Handle, CloseBtnDrawDetails,
FCloseButtonsRect[TabIndex]);
end;
end;
end;
如果您使用的是 vcl 样式,则必须编写一个 vcl 样式钩子来在选项卡控件中绘制关闭按钮,请查看 Vcl.Styles.ColorTabs 单元(在这些文章中介绍) 使用VCL Styles,为 TTabColorControlStyleHook 添加了边框)以了解编写这样的样式钩子需要什么。除了在选项卡中绘制按钮的代码之外,您还必须处理 WM_MOUSEMOVE 和 WM_LBUTTONUP 消息(在样式挂钩中)以更改按钮的状态(正常、热)并检测关闭按钮中的单击。
如果您在实现样式挂钩时遇到问题,请告诉我在这里发布完整的解决方案。
更新
我刚刚编写了这个简单的样式挂钩来添加对选项卡中关闭按钮的支持。
uses
Vcl.Styles,
Vcl.Themes;
type
TTabControlStyleHookBtnClose = class(TTabControlStyleHook)
private
FHotIndex : Integer;
FWidthModified : Boolean;
procedure WMMouseMove(var Message: TMessage); message WM_MOUSEMOVE;
procedure WMLButtonUp(var Message: TWMMouse); message WM_LBUTTONUP;
function GetButtonCloseRect(Index: Integer):TRect;
strict protected
procedure DrawTab(Canvas: TCanvas; Index: Integer); override;
procedure MouseEnter; override;
procedure MouseLeave; override;
public
constructor Create(AControl: TWinControl); override;
end;
constructor TTabControlStyleHookBtnClose.Create(AControl: TWinControl);
begin
inherited;
FHotIndex:=-1;
FWidthModified:=False;
end;
procedure TTabControlStyleHookBtnClose.DrawTab(Canvas: TCanvas; Index: Integer);
var
Details : TThemedElementDetails;
ButtonR : TRect;
FButtonState: TThemedWindow;
begin
inherited;
if (FHotIndex>=0) and (Index=FHotIndex) then
FButtonState := twSmallCloseButtonHot
else
if Index = TabIndex then
FButtonState := twSmallCloseButtonNormal
else
FButtonState := twSmallCloseButtonDisabled;
Details := StyleServices.GetElementDetails(FButtonState);
ButtonR:= GetButtonCloseRect(Index);
if ButtonR.Bottom - ButtonR.Top > 0 then
StyleServices.DrawElement(Canvas.Handle, Details, ButtonR);
end;
procedure TTabControlStyleHookBtnClose.WMLButtonUp(var Message: TWMMouse);
Var
LPoint : TPoint;
LIndex : Integer;
begin
LPoint:=Message.Pos;
for LIndex := 0 to TabCount-1 do
if PtInRect(GetButtonCloseRect(LIndex), LPoint) then
begin
if Control is TPageControl then
begin
TPageControl(Control).Pages[LIndex].Parent:=nil;
TPageControl(Control).Pages[LIndex].Free;
end;
break;
end;
end;
procedure TTabControlStyleHookBtnClose.WMMouseMove(var Message: TMessage);
Var
LPoint : TPoint;
LIndex : Integer;
LHotIndex : Integer;
begin
inherited;
LHotIndex:=-1;
LPoint:=TWMMouseMove(Message).Pos;
for LIndex := 0 to TabCount-1 do
if PtInRect(GetButtonCloseRect(LIndex), LPoint) then
begin
LHotIndex:=LIndex;
break;
end;
if (FHotIndex<>LHotIndex) then
begin
FHotIndex:=LHotIndex;
Invalidate;
end;
end;
function TTabControlStyleHookBtnClose.GetButtonCloseRect(Index: Integer): TRect;
var
FButtonState: TThemedWindow;
Details : TThemedElementDetails;
R, ButtonR : TRect;
begin
R := TabRect[Index];
if R.Left < 0 then Exit;
if TabPosition in [tpTop, tpBottom] then
begin
if Index = TabIndex then
InflateRect(R, 0, 2);
end
else
if Index = TabIndex then
Dec(R.Left, 2)
else
Dec(R.Right, 2);
Result := R;
FButtonState := twSmallCloseButtonNormal;
Details := StyleServices.GetElementDetails(FButtonState);
if not StyleServices.GetElementContentRect(0, Details, Result, ButtonR) then
ButtonR := Rect(0, 0, 0, 0);
Result.Left :=Result.Right - (ButtonR.Width) - 5;
Result.Width:=ButtonR.Width;
end;
procedure TTabControlStyleHookBtnClose.MouseEnter;
begin
inherited;
FHotIndex := -1;
end;
procedure TTabControlStyleHookBtnClose.MouseLeave;
begin
inherited;
if FHotIndex >= 0 then
begin
FHotIndex := -1;
Invalidate;
end;
end;
通过这种方式注册
TStyleManager.Engine.RegisterStyleHook(TCustomTabControl, TTabControlStyleHookBtnClose);
TStyleManager.Engine.RegisterStyleHook(TTabControl, TTabControlStyleHookBtnClose);
这是一个演示
我一直在研究这个示例,并且我让它在 delphi XE6 上的 Metro UI 上运行。
为了获得选项卡名称和按钮之间的正确距离,我的解决方法是修改此行
Result.Left := Result.Right - (ButtonR.Width);
//it was Result.Left := Result.Right - (ButtonR.Width) -5;
并在 PageController 属性上设置更大的 TabWith。
另外,请记住,“注册”行在单元结束之前进入初始化类。
//...all the code of the unit
Initialization
TStyleManager.Engine.RegisterStyleHook(TCustomTabControl,
TTabControlStyleHookBtnClose);
TStyleManager.Engine.RegisterStyleHook(TTabControl,
TTabControlStyleHookBtnClose);
end.//final unit "end" =D
我已经尝试过并且有效。但是,如果标题名称很长,则标题名称会被创建的关闭按钮覆盖