自绘ListBox的两种效果

　本文利用Listbox自绘实现了两种特殊效果（见图），左边的风格是自己突然灵感触发想到的，右边的风格来自＂C++ Builder 研究＂的一个帖子，老妖用BCB实现了，这里则用Delphi实现它。


演示图片：
自绘ListBox的效果


 


//--------------------------------------------------------------------------

unit DrawListItem;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ImgList, jpeg, ExtCtrls;

type
TForm1 = class(TForm)
lsbRight: TListBox;
ImageList1: TImageList;
StaticText1: TStaticText;
lsbLeft: TListBox;
imgHouse: TImage;
imgHouseGray: TImage;
procedure FormCreate(Sender: TObject);
procedure lsbRightDrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
procedure lsbRightClick(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure lsbLeftDrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
private

public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

{========================================================================
  DESIGN BY :  彭国辉
  DATE:        2004-11-29
  SITE:        http://kacarton.yeah.net/
  BLOG:        http://blog.csdn.net/nhconch
  EMAIL:       kacarton#sohu.com

  文章为作者原创，转载前请先与本人联系，转载请注明文章出处、保留作者信息，谢谢支持！
=========================================================================}

procedure TForm1.FormCreate(Sender: TObject);
var
i: integer;
begin
  lsbRight.Style := lbOwnerDrawFixed;
  lsbRight.Ctl3D := false;
  lsbRight.ItemHeight := 50;
  lsbRight.Items.Add('C++ Builder 研究 致力于BCB的学习探讨和研究'#13'ccrun(老妖)');
  lsbRight.Items.Add('编程手札 My Developer Knowledge Base'#13'http://blog.csdn.net/nhconch'#13'天蝎蝴蝶');
  for i:=3 to 10 do begin
    lsbRight.Items.Add('ListBox Items of ' + IntTostr(i) + #13'Second of '
    + IntToStr(i) + #13'Third of ' + IntToStr(i));
  end;
  
  lsbLeft.Style := lbOwnerDrawFixed;
  lsbLeft.Ctl3D := false;
  lsbLeft.ItemHeight := 90;
  lsbLeft.Items.Add('编程手札');
  lsbLeft.Items.Add('My Developer Knowledge Base');
  lsbLeft.Items.Add('站长:天蝎蝴蝶');
  lsbLeft.Items.Add('http://blog.csdn.net/nhconch');
end;

procedure TForm1.lsbRightDrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
var
strTemp: String;
begin
  //文字颜色
    lsbRight.Canvas.Font.Color := clBlack;
  //设置背景颜色并填充背景
    lsbRight.Canvas.Brush.Color := clWhite;
  lsbRight.Canvas.FillRect (Rect);
  //设置圆角矩形颜色并画出圆角矩形
    lsbRight.Canvas.Brush.Color := TColor($00FFF7F7);
  lsbRight.Canvas.Pen.Color := TColor($00131315);
  lsbRight.Canvas.RoundRect(Rect.Left + 3, Rect.Top + 3,
  Rect.Right - 2, Rect.Bottom - 2, 8, 8);
  //以不同的宽度和高度再画一次，实现立体效果
    lsbRight.Canvas.RoundRect(Rect.Left + 3, Rect.Top + 3,
  Rect.Right - 3, Rect.Bottom - 3, 5, 5);
  //如果是当前选中项
    if(odSelected in State) then
  begin
    //以不同的背景色画出选中项的圆角矩形
        lsbRight.Canvas.Brush.Color := TColor($00FFB2B5);
    lsbRight.Canvas.RoundRect(Rect.Left + 3, Rect.Top + 3,
    Rect.Right - 3, Rect.Bottom - 3, 5, 5);
    //选中项的文字颜色
        lsbRight.Canvas.Font.Color := clBlue;
    //如果当前项拥有焦点，画焦点虚框，当系统再绘制时变成XOR运算从而达到擦除焦点虚框的目的
        if(odFocused in State) then DrawFocusRect(lsbRight.Canvas.Handle, Rect);
  end;
  //画出图标
    ImageList1.Draw(lsbRight.Canvas, Rect.Left + 7,
  Rect.top + (lsbRight.ItemHeight - ImageList1.Height) div 2, Index, true);
  //分别绘出三行文字
    strTemp := lsbRight.Items.Strings[Index];
  lsbRight.Canvas.TextOut(Rect.Left + 32 + 10, Rect.Top + 4
  , Copy(strTemp, 1, Pos(#13, strTemp)-1));
  strTemp := Copy(strTemp, Pos(#13, strTemp)+1, Length(strTemp));
  lsbRight.Canvas.TextOut(Rect.Left + 32 + 10, Rect.Top + 18,
  Copy(strTemp, 1, Pos(#13, strTemp)-1));
  lsbRight.Canvas.TextOut(Rect.Left + 32 + 10, Rect.Top + 32,
  Copy(strTemp, Pos(#13, strTemp)+1, Length(strTemp)));
end;

procedure TForm1.lsbRightClick(Sender: TObject);
begin
  StaticText1.Caption := ' ' + lsbRight.Items.Strings[lsbRight.ItemIndex];
end;

procedure TForm1.FormShow(Sender: TObject);
begin
  lsbRight.ItemIndex := 0;
  lsbRight.Repaint();
  
  lsbLeft.ItemIndex := 0;
  lsbLeft.Repaint();
end;

procedure TForm1.lsbLeftDrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
var
r: TRect;
begin
  with lsbLeft.Canvas do begin
      //设置填充的背景颜色并填充背景
        Brush.Color := clWhite;
      FillRect (Rect);
      //绘制圆角矩形
        if (odSelected in State) then   //选中项的圆角矩形颜色
            Pen.Color := $FFB2B5
      else                            //未选中项的圆角矩形颜色
            Pen.Color := clSilver;
      Brush.Style := bsClear;
      SetRect(r, Rect.Left+3, Rect.Top+3, Rect.Right-3, Rect.Bottom-3);
      RoundRect(r.Left, r.Top, r.Right, r.Bottom, 10, 10);
      //画出图标
        if (odSelected in State) then   //选中项的图像
            Draw(r.Left + (r.Right - r.Left - imgHouse.Width) shr 1,
      r.Top + 2, imgHouse.Picture.Graphic)
      else                            //未选中项的图像
            Draw(r.Left + (r.Right - r.Left - imgHouseGray.Width) shr 1,
      r.Top + 2, imgHouseGray.Picture.Graphic);
      //填充文字区背景
        r.Top := r.Bottom - Abs(Font.Height) - 4;
      Brush.Style := bsSolid;
      if (odSelected in State) then   //选中项的背景颜色
            Brush.Color := $FFB2B5
      else                            //未选中项的背景颜色
            Brush.Color := clSilver;
      FillRect(r);
      //输出文字，仅支持单行
        Font.Color := clBlack;
      r.Top := r.Top + 2; //计算文字顶点位置，(水平居中,DT_CENTER不可用)
        DrawText(Handle, PChar(TListBox(Control).Items.Strings[Index]), -1, r
      , DT_CENTER or DT_END_ELLIPSIS{ or DT_WORDBREAK});
      //画焦点虚框，当系统再绘制时，变成XOR运算，从而达到擦除焦点虚框的目的
        if(odFocused in State) then DrawFocusRect(Rect);
    end;
  end;
  
end.