自画TListView带进度条的Item

 
自画 TlistView 带进度条的 Item
TListView的Item条一般是由系统自画的,但电驴就实现了自画,使之看起来很漂亮,我们用DELPHI也可以实现!
 
首先要引用 CommCtrl 单元,这是TListView底层控制单元:
uses
  CommCtrl;
 
// 画状态条
procedure DrawSubItem(LV: TListView; Item: TListItem; SubItem: Integer;
 Prosition: Single; Max, Style: Integer; IsShowProgress: Boolean;
 DrawColor: TColor = $00005B00 ;
 FrameColor: TColor = $00002F00 );
// 获取 SubItem 的区域
  function GetItemRect(LV_Handle, iItem, iSubItem: Integer): TRect;
  var
    Rect: TRect;
  begin
    ListView_GetSubItemRect(LV_Handle, iItem, iSubItem, LVIR_LABEL, @Rect);
    Result := Rect;
  end ;
var
  PaintRect, r: TRect;
 i, iWidth, x, y: integer;
 S: string ;
begin
 try
 
    with lv do
    begin
      //LockPaint := True;
      PaintRect := GetItemRect(LV.Handle, Item.Index, SubItem);
     r := PaintRect;
//      if SubItem = DrawSubItem then
      Begin
        // 这一段是算出百分比
        if Prosition >= Max then
          Prosition := 100
        else
          if Prosition <= 0 then
            Prosition := 0
          else
            Prosition := Round((Prosition / Max) * 100 );
 
        if (Prosition = 0 ) and ( not IsShowProgress) then
        begin
        // 如果是百分比是 0 ,就直接显示空白
          Canvas.FillRect(r);
 
        end
        else
        begin
        // 先直充背景色
          Canvas.FillRect(r);
          Canvas.Brush.Color := Color;
//          Canvas.FillRect(r);
 
        // 画一个外框
          InflateRect(r, - 2 , - 2 );
          Canvas.Brush.Color := FrameColor; //$00002F00;
          Canvas.FrameRect(R);
 
          Canvas.Brush.Color := Color;
          InflateRect(r, - 1 , - 1 );
//          Canvas.FillRect(r);
 
          InflateRect(r, - 1 , - 1 );
        // 根据百分比算出要画的进度条内容宽度
          iWidth := R.Right - Round((R.Right - r.Left) * (( 100 - Prosition) /
            100 ));
          case Style of
            0 : // 进度条类型,实心填充
              begin
                Canvas.Brush.Color := DrawColor;
                r.Right := iWidth;
                Canvas.FillRect(r);
              end ;
            1 : // 进度条类型,竖线填充
              begin
                i := r.Left;
                while i < iWidth do
                begin
                  Canvas.Pen.Color := Color;
                  Canvas.MoveTo(i, r.Top);
                  Canvas.Pen.Color := DrawColor;
                  canvas.LineTo(i, r.Bottom);
                  Inc(i, 3 );
                end ;
              end ;
          end ;
// 画好了进度条后,现在要做的就是显示进度数字了
          Canvas.Brush.Style := bsClear;
          if Prosition = Round(Prosition) then
            S := Format( '%d%%' , [Round(Prosition)])
          else
            S := FormatFloat( '#0.0' , Prosition);
 
          with PaintRect do
          begin
            x := Left + (Right - Left + 1 - Canvas.TextWidth(S)) div 2 ;
            y := Top + (Bottom - Top + 1 - Canvas.TextHeight(S)) div 2 ;
          end ;
          SetBkMode(Canvas.handle, TRANSPARENT);
          Canvas.TextRect(PaintRect, x, y, S);
 
        end ;
// 进度条全部画完,把颜色设置成默认色了
        Canvas.Brush.Color := Color;
 
      end
    end ;
  except
  end ;
end ;
 
 
上面是画进度条的,现在要给 TlistView 处理 Item 重绘的消息,事件是 On CustomDrawItem 需要说明的是,如果想要随心所欲的自画 Item ,那么就要全部自己来完成,不再需要系统来处理:
procedure TForm1.ListView1CustomDrawItem(
 Sender: TCustomListView; Item: TListItem; State: TCustomDrawState;
  var DefaultDraw: Boolean);
var
  BoundRect, Rect: TRect;
 i: integer;
 TextFormat: Word;
 LV: TListView;
 
// 这个子过程是用来画 CheckBox ImageList
  procedure Draw_CheckBox_ImageList(r: TRect; aCanvas: TCanvas; Checked: Boolean);
  var
    R1: TRect;
    i: integer;
  begin
    if Sender.Checkboxes then
    begin
      aCanvas.Pen.Color := clBlack;
      aCanvas.Pen.Width := 2 ;
      // CheckBox 外框
      aCanvas.Rectangle(r.Left + 2 , r.Top + 2 , r.Left + 14 , r.Bottom - 2 );
      if Checked then
      begin // CheckBox 的勾
        aCanvas.MoveTo(r.Left + 4 , r.Top + 6 );
        aCanvas.LineTo(r.Left + 6 , r.Top + 11 );
        aCanvas.LineTo(r.Left + 11 , r.Top + 5 );
      end ;
      aCanvas.Pen.Width := 1 ;
    end ;
    // 开始画图标
    i := PDownLoadListItem(Item.Data)^.StatsImageIndex;
    if i > - 1 then
    begin
    // 获取图标的 RECT
      if Boolean(ListView_GetSubItemRect(sender.Handle, item.Index, 0 , LVIR_ICON, @R1)) then
      begin
        ImageList_Stats.Draw(LV.Canvas, R1.Left, R1.Top, i);
        if item.ImageIndex > - 1 then
          LV.SmallImages.Draw(LV.Canvas, R1.Right + 2 , R1.Top, item.ImageIndex);
      end ;
 
    end ;
  end ;
begin
  LV := ListView1;
 BoundRect := Item.DisplayRect(drBounds);
 InflateRect(BoundRect, - 1 , 0 );
 
// 这个地方你可以根据自己的要求设置成想要的颜色,实现突出显示
  LV.Canvas.Font.Color := clBtnText;
 
// 查看是否是被选中
  if Item.Selected then
 begin
    if cdsFocused in State then
    begin
      LV.Canvas.Brush.Color := $00ECCCB9 ; // //clHighlight;
    end
    else
    begin
      LV.Canvas.Brush.Color := $00F8ECE5 ; //clSilver;
    end ;
  end
 else
 begin
    if (Item.Index mod 2 ) = 0 then
      LV.Canvas.Brush.Color := clWhite
    else
      LV.Canvas.Brush.Color := $00F2F2F2 ;
  end ;
 
 LV.Canvas.FillRect(BoundRect); // 初始化背景
 
  for i := 0 to LV.Columns.Count - 1 do
 begin
  // 获取 SubItem Rect
    ListView_GetSubItemRect(LV.Handle, Item.Index, i, LVIR_LABEL, @Rect);
    case LV.Columns[i].Alignment of
      taLeftJustify:
        TextFormat := 0 ;
      taRightJustify:
        TextFormat := DT_RIGHT;
      taCenter:
        TextFormat := DT_CENTER;
    end ;
    case i of
      0 : // Caption 0 就是表示 Caption ,这不是 Subitems[0]
        begin
// 先画选择框与图标
          Draw_CheckBox_ImageList(BoundRect, LV.Canvas, Item.Checked);
// 再画 Caption 的文字
          InflateRect(Rect, -( 5 + ImageList_Stats.Width), 0 ); // 向后移 3 个像素 , 避免被后面画线框时覆盖
          DrawText(
            LV.Canvas.Handle,
            PCHAR(Item.Caption),
            Length(Item.Caption),
            Rect,
            DT_VCENTER or DT_SINGLELINE or DT_END_ELLIPSIS or TextFormat);
        end ;
      1 ..MaxInt: // Subitems[i]
        begin
          if i - 1 = 2 then // 显示状态条
          begin
// 开始处理进度条了,这个示例是第 3 栏显示进度条,可以自己随便定义
            DrawSubItem(TListView(Sender),
              item,
              i,
              StrToFloatDef(Item.SubItems[i - 1 ], 0 ),
              100 ,
              0 ,
              True,
 // 这里用了一个 Lable 来选颜色,你自己可以使用一个变量来代替
             LableProgressColor.Color, // 进度条外框颜色
              LableProgressColor.Color  // 进度条颜色
);
 
          end
          else
// SubItem 的文字
            if i - 1 <= Item.SubItems.Count - 1 then
              DrawText(
                LV.Canvas.Handle,
                PCHAR(Item.SubItems[i - 1 ]),
                Length(Item.SubItems[i - 1 ]),
                Rect,
                DT_VCENTER or DT_SINGLELINE or DT_END_ELLIPSIS or TextFormat);
 
 
 
        end ;
    end ;
 
  end ;
 
 
 LV.Canvas.Brush.Color := clWhite;
 
  if Item.Selected then // 画选中条外框
  begin
    if cdsFocused in State then // 控件是否处于激活状态
      LV.Canvas.Brush.Color := $00DAA07A // $00E2B598; //clHighlight;
    else
      LV.Canvas.Brush.Color := $00E2B598 ; //$00DAA07A // clHighlight;
    LV.Canvas.FrameRect(BoundRect); //
  end ;
 
 DefaultDraw := False; // 不让系统画了
 
  with Sender.Canvas do
    if Assigned(Font.OnChange) then Font.OnChange(Font);
 
 
 
end ;
function ReDrawItem(HwndLV: HWND; ItemIndex: integer): boolean;
begin
  Result := ListView_RedrawItems(HwndLV, ItemIndex, ItemIndex);
end;
//使用:
item:=ListView1.Selected;
item.subitems[1]:='30';//设置为30%
//然后刷新这个item
ReDrawItem(ListView1.handle,Item.index);
 
不用进度条时的效果图:
 

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