在AdvancedCustomDrawItem中如何绘制TTreeView的样式选择矩形？ [英] How to draw TTreeView's styled selection rectangle during AdvancedCustomDrawItem?

问题描述

我正在使用 OnAdvancedCustomDrawItem 事件从头开始自定义 TTreeView 绘图，我不知道如何呈现这些选择和我的主人背景中的热矩形正确的绘制项目？他们是Vista / 7风格，所以我不能简单地填充一些纯色的背景。

我试图在 cdPostPaint ，但是如果我在 cdPrePaint 阶段留下 DefaultDraw：= True 来绘制选择背景，则会发生完整的默认绘图，其中包括

 程序TForm1.TreeView1AdvancedCustomDrawItem（发件人：TCustomTreeView; 
节点：TTreeNode;状态：TCustomDrawState;舞台：TCustomDrawStage; var PaintImages，
 DefaultDraw：Boolean）; 
 begin 
 case 
 cdPreErase：
 begin 
 DefaultDraw：= True; 
结束
 
 cdPostErase：
 begin 
 DefaultDraw：= True; 
结束
 
 cdPrePaint：
 begin 
 //我以为这将只绘制所选/热的背景，
 //但是这将绘制整个项目，包括文本。 
 DefaultDraw：= True; 
结束
 
 cdPostPaint：
 begin 
 DefaultDraw：= False; 
 
 //画我的所有者绘制文本
 // ......... 
 end; 
结束
 
 PaintImages：= False; 
结束
  

解决方案

这是我的解决方案（测试）。 >

请注意，TreeView必须具有 HotTrack：= True 可以正常绘制热门项目。

当主题未启用时，还必须附加绘图。

 使用
 UxTheme，
主题; 
 
 const 
 TreeExpanderSpacing = 6; 
 
程序TForm1.DrawExpander（ACanvas：TCanvas; ATextRect：TRect; AExpanded：Boolean; 
 AHot：Boolean）; 
 var 
 ExpanderRect：TRect; 
图形：IGPGraphics; 
积分：TGPPoint数组; 
刷：IGPBrush; 
笔：IGPPen; 
 ThemeData：HTHEME; 
 ElementPart：整数; 
 ElementState：Integer; 
 ExpanderSize：TSize; 
 UnthemedColor：TColor; 
 begin 
如果ThemeServices.ThemesEnabled然后
开始
如果AHot然后
 ElementPart：= TVP_HOTGLYPH 
 else 
 ElementPart：= TVP_GLYPH; 
 
如果AExpanded然后
 ElementState：= GLPS_OPENED 
 else 
 ElementState：= GLPS_CLOSED; 
 
 ThemeData：= OpenThemeData（TreeView1.Handle，VSCLASS_TREEVIEW）; 
 GetThemePartSize（ThemeData，ACanvas.Handle，ElementPart，ElementState，nil，
 TS_TRUE，ExpanderSize）; 
 ExpenderRect.Left：= ATextRect.Left  -  TreeExpanderSpacing  -  ExpanderSize.cx; 
 ExpanderRect.Right：= ExpanderRect.Left + ExpanderSize.cx; 
 ExpanderRect.Top：= ATextRect.Top +（ATextRect.Bottom  -  ATextRect.Top  -  ExpanderSize.cy）div 2; 
 ExpanderRect.Bottom：= ExpanderRect.Top + ExpanderSize.cy; 
 DrawThemeBackground（ThemeData，ACanvas.Handle，ElementPart，ElementState，ExpanderRect，nil）; 
 CloseThemeData（ThemeData）; 
 end 
 else 
 begin 
 
 //没有主题的绘图扩展器
 
图形：= TGPGraphics.Create（ACanvas.Handle）; 
 Graphics.SmoothingMode：= SmoothingModeHighQuality; 
 
 ExpanderRect：= ATextRect; 
 ExpanderRect.Right：= ATextRect.Left  -  TDPIAware.GetScaledSize（TreeExpanderSpacing96dpi）; 
 ExpanderRect.Left：= ATextRect.Left  -  TDPIAware.GetScaledSize（TreeExpanderSpacing96dpi） -  
 TDPIAware.GetScaledSize（Max（TreeExpanderCollapsedWidth96dpi，TreeExpanderExpandedWidth96dpi））; 
 
如果ASelected然后
 UnthemedColor：= ColorToRGB（clHighlightText）
 else 
如果AExpanded然后
 UnthemedColor：= clBlack 
 else 
 UnthemedColor：= clGray; 
 
 SetLength（Points，3）; 
如果AExpanded然后
开始
点[0]：= TGPPoint.Create（ExpanderRect.Right，ExpanderRect.Top + 
（ExpanderRect.Bottom  -  ExpanderRect.Top  -  TreeExpanderExpandedHeight96dpi）div 2）; 
 Points [1]：= TGPPoint.Create（ExpanderRect.Right，ExpanderRect.Top + 
（ExpanderRect.Bottom  -  ExpanderRect.Top + TreeExpanderExpandedHeight96dpi）div 2）; 
 Points [2]：= TGPPoint.Create（ExpanderRect.Right  -  TreeExpanderExpandedWidth96dpi，
 ExpanderRect.Top +（ExpanderRect.Bottom  -  ExpanderRect.Top + 
 TreeExpanderExpandedHeight96dpi）div 2）; 
画笔：= TGPSolidBrush.Create（TGPColor.CreateFromColorRef（UnthemedColor））; 
 Graphics.FillPolygon（Brush，Points）; 
 end 
 else 
 begin 
 Points [0]：= TGPPoint.Create（ExpanderRect.Right  -  TreeExpanderCollapsedWidth96dpi，
 ExpanderRect.Top +（ExpanderRect.Bottom  -  ExpanderRect。顶部 -  
 TreeExpanderCollapsedHeight96dpi）div 2）; 
 Points [1]：= TGPPoint.Create（ExpanderRect.Right，
 ExpanderRect.Top +（ExpanderRect.Bottom  -  ExpanderRect.Top）div 2）; 
 Points [2]：= TGPPoint.Create（ExpanderRect.Right  -  TreeExpanderCollapsedWidth96dpi，
 ExpanderRect.Top +（ExpanderRect.Bottom  -  ExpanderRect.Top + 
 TreeExpanderCollapsedHeight96dpi）div 2）; 
笔：= TGPPen.Create（TGPColor.CreateFromColorRef（UnthemedColor））; 
 Graphics.DrawPolygon（Pen，Points）; 
结束
结束
结束
 
程序TForm1.TreeView1AdvancedCustomDrawItem（发件人：TCustomTreeView; 
节点：TTreeNode;状态：TCustomDrawState;舞台：TCustomDrawStage; var PaintImages，
 DefaultDraw：Boolean）; 
 var 
 NodeRect：TRect; 
 NodeTextRect：TRect; 
文本：string; 
 ThemeData：HTHEME; 
 TreeItemState：Integer; 
 begin 
如果Stage = cdPrePaint然后
 begin 
 NodeRect：= Node.DisplayRect（False）; 
 NodeTextRect：= Node.DisplayRect（True）; 
 
 //绘制背景
 if（cdsSelected in State）and Sender.Focused then 
 TreeItemState：= TREIS_SELECTED 
 else 
 if（cdsSelected in State）和（cdsHot在州）然后
 TreeItemState：= TREIS_HOTSELECTED 
 else 
如果cdsSelected在州然后
 TreeItemState：= TREIS_SELECTEDNOTFOCUS 
 else 
如果cdsHot在状态那么
 TreeItemState：= TREIS_HOT 
 else 
 TreeItemState：= TREEITEMStateFiller0; 
 
如果TreeItemState<> TREEITEMStateFiller0然后
 begin 
 ThemeData：= OpenThemeData（Sender.Handle，VSCLASS_TREEVIEW）; 
 DrawThemeBackground（ThemeData，Sender.Canvas.Handle，TVP_TREEITEM，TreeItemState，
 NodeRect，nil）; 
 CloseThemeData（ThemeData）; 
结束
 
 //绘图扩展器
如果Node.HasChildren然后
 DrawExpander（Sender.Canvas，NodeTextRect，Node.Expanded，cdsHot在状态）; 
 
 //绘制主文本
 SetBkMode（Sender.Canvas.Handle，TRANSPARENT）; 
 SetTextColor（Sender.Canvas.Handle，clBlue）; 
 
文本：= Node.Text; 
 Sender.Canvas.TextRect（NodeTextRect，Text，
 [tfVerticalCenter，tfSingleLine，tfEndEllipsis，tfLeft]）; 
 
 //某些扩展图... 
 
 end; 
 
 PaintImages：= False; 
 DefaultDraw：= False; 
结束
  

I'm doing custom TTreeView drawing from scratch using OnAdvancedCustomDrawItem event, and I wonder how to render these selection and hot rectangles correctly in the background of my owner-draw items? They are Vista/7 styled so I cannot simply fill the background in some solid color.

I tried to draw my items at cdPostPaint stage, but if I leave DefaultDraw := True atcdPrePaint stage to draw selection background, the complete default drawing occurs, including text of items.

procedure TForm1.TreeView1AdvancedCustomDrawItem(Sender: TCustomTreeView;
  Node: TTreeNode; State: TCustomDrawState; Stage: TCustomDrawStage; var PaintImages,
  DefaultDraw: Boolean);
begin
  case Stage of
    cdPreErase:
    begin
      DefaultDraw := True;
    end;

    cdPostErase:
    begin
      DefaultDraw := True;
    end;

    cdPrePaint:
    begin
      // I thought this will paint only the selected/hot backgrounds, 
      // however this will paint whole item, including text.
      DefaultDraw := True;
    end;

    cdPostPaint:
    begin
      DefaultDraw := False;

      // painting my owner-draw text
      // .........
    end;
  end;

  PaintImages := False;
end;

解决方案

Here is my solution (tested).

Note the TreeView must have HotTrack := True to draw hot items normally.

There also must be additional drawing when themes not enabled.

uses
  UxTheme,
  Themes;

const
  TreeExpanderSpacing = 6;

procedure TForm1.DrawExpander(ACanvas: TCanvas; ATextRect: TRect; AExpanded: Boolean;
  AHot: Boolean);
var
  ExpanderRect: TRect;
  Graphics: IGPGraphics;
  Points: array of TGPPoint;
  Brush: IGPBrush;
  Pen: IGPPen;
  ThemeData: HTHEME;
  ElementPart: Integer;
  ElementState: Integer;
  ExpanderSize: TSize;
  UnthemedColor: TColor;
begin
  if ThemeServices.ThemesEnabled then
  begin
    if AHot then
      ElementPart := TVP_HOTGLYPH
    else
      ElementPart := TVP_GLYPH;

    if AExpanded then
      ElementState := GLPS_OPENED
    else
      ElementState := GLPS_CLOSED;

    ThemeData := OpenThemeData(TreeView1.Handle, VSCLASS_TREEVIEW);
    GetThemePartSize(ThemeData, ACanvas.Handle, ElementPart, ElementState, nil,
      TS_TRUE, ExpanderSize);
    ExpanderRect.Left := ATextRect.Left - TreeExpanderSpacing - ExpanderSize.cx;
    ExpanderRect.Right := ExpanderRect.Left + ExpanderSize.cx;
    ExpanderRect.Top := ATextRect.Top + (ATextRect.Bottom - ATextRect.Top - ExpanderSize.cy) div 2;
    ExpanderRect.Bottom := ExpanderRect.Top + ExpanderSize.cy;
    DrawThemeBackground(ThemeData, ACanvas.Handle, ElementPart, ElementState, ExpanderRect, nil);
    CloseThemeData(ThemeData);
  end
  else
  begin

    // Drawing expander without themes enabled

    Graphics := TGPGraphics.Create(ACanvas.Handle);
    Graphics.SmoothingMode := SmoothingModeHighQuality;

    ExpanderRect := ATextRect;
    ExpanderRect.Right := ATextRect.Left - TDPIAware.GetScaledSize(TreeExpanderSpacing96dpi);
    ExpanderRect.Left := ATextRect.Left - TDPIAware.GetScaledSize(TreeExpanderSpacing96dpi) -
      TDPIAware.GetScaledSize(Max(TreeExpanderCollapsedWidth96dpi, TreeExpanderExpandedWidth96dpi));

    if ASelected then
      UnthemedColor := ColorToRGB(clHighlightText)
    else
      if AExpanded then
        UnthemedColor := clBlack
      else
        UnthemedColor := clGray;

    SetLength(Points, 3);
    if AExpanded then
    begin
      Points[0] := TGPPoint.Create(ExpanderRect.Right, ExpanderRect.Top +
        (ExpanderRect.Bottom - ExpanderRect.Top - TreeExpanderExpandedHeight96dpi) div 2);
      Points[1] := TGPPoint.Create(ExpanderRect.Right, ExpanderRect.Top +
        (ExpanderRect.Bottom - ExpanderRect.Top + TreeExpanderExpandedHeight96dpi) div 2);
      Points[2] := TGPPoint.Create(ExpanderRect.Right - TreeExpanderExpandedWidth96dpi,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top +
        TreeExpanderExpandedHeight96dpi) div 2);
      Brush := TGPSolidBrush.Create(TGPColor.CreateFromColorRef(UnthemedColor));
      Graphics.FillPolygon(Brush, Points);
    end
    else
    begin
      Points[0] := TGPPoint.Create(ExpanderRect.Right - TreeExpanderCollapsedWidth96dpi,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top -
        TreeExpanderCollapsedHeight96dpi) div 2);
      Points[1] := TGPPoint.Create(ExpanderRect.Right,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top) div 2);
      Points[2] := TGPPoint.Create(ExpanderRect.Right - TreeExpanderCollapsedWidth96dpi,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top +
        TreeExpanderCollapsedHeight96dpi) div 2);
      Pen := TGPPen.Create(TGPColor.CreateFromColorRef(UnthemedColor));
      Graphics.DrawPolygon(Pen, Points);
    end;
  end;
end;

procedure TForm1.TreeView1AdvancedCustomDrawItem(Sender: TCustomTreeView;
  Node: TTreeNode; State: TCustomDrawState; Stage: TCustomDrawStage; var PaintImages,
  DefaultDraw: Boolean);
var
  NodeRect: TRect;
  NodeTextRect: TRect;
  Text: string;
  ThemeData: HTHEME;
  TreeItemState: Integer;
begin
  if Stage = cdPrePaint then
  begin
    NodeRect := Node.DisplayRect(False);
    NodeTextRect := Node.DisplayRect(True);

    // Drawing background
    if (cdsSelected in State) and Sender.Focused then
      TreeItemState := TREIS_SELECTED
    else
      if (cdsSelected in State) and (cdsHot in State) then
        TreeItemState := TREIS_HOTSELECTED
      else
        if cdsSelected in State then
          TreeItemState := TREIS_SELECTEDNOTFOCUS
        else
          if cdsHot in State then
            TreeItemState := TREIS_HOT
          else
            TreeItemState := TREEITEMStateFiller0;

    if TreeItemState <> TREEITEMStateFiller0 then
    begin
      ThemeData := OpenThemeData(Sender.Handle, VSCLASS_TREEVIEW);
      DrawThemeBackground(ThemeData, Sender.Canvas.Handle, TVP_TREEITEM, TreeItemState,
        NodeRect, nil);
      CloseThemeData(ThemeData);
    end;

    // Drawing expander
    if Node.HasChildren then
      DrawExpander(Sender.Canvas, NodeTextRect, Node.Expanded, cdsHot in State);

    // Drawing main text
    SetBkMode(Sender.Canvas.Handle, TRANSPARENT);
    SetTextColor(Sender.Canvas.Handle, clBlue);

    Text := Node.Text;
    Sender.Canvas.TextRect(NodeTextRect, Text,
      [tfVerticalCenter, tfSingleLine, tfEndEllipsis, tfLeft]);

    // Some extended drawing...

  end;

  PaintImages := False;
  DefaultDraw := False;
end;

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