Delphi 7的ListView自画CheckBox

原创

无幻__ 2021-08-30 11:46:30 博主文章分类：5.2 Delphi编程 ©著作权

文章标签 listview delphi integer div forms 文章分类 代码人生

©著作权归作者所有：来自51CTO博客作者无幻__的原创作品，请联系作者获取转载授权，否则将追究法律责任

Delphi 7下的ListView其中有个ViewStyle风格是vsReport，我们大多也是使用这个风格。在此风格下可以设置首列前面有个CheckBox复选框，但是我们更多时候，需要的是在最后一列显示CheckBox复选框。于是，我们得自己重画子项为CheckBox，然而画完之后，在调整列宽时，不会触发ListView刷新，导致影像残留，于是接着禁止用户调整列宽。

示例源码如下：

001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
091
092
093
094
095
096
097
098
099
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Grids, ValEdit, StdCtrls, CheckLst, ComCtrls, CommCtrl, Math,
  XPMan;

type
  TForm1 = class(TForm)
    lv1: TListView;
    xpmnfst1: TXPManifest;
    procedure lv1CustomDrawSubItem(Sender: TCustomListView;
      Item: TListItem; SubItem: Integer; State: TCustomDrawState;
      var DefaultDraw: Boolean);
    procedure lv1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    FListViewOldWndProc: TWndMethod;
    procedure ListViewNewWndProc(var Msg: TMessage);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  FListViewOldWndProc := lv1.WindowProc;
  lv1.WindowProc := ListViewNewWndProc;
  with lv1 do
  begin
    RowSelect := True;
    ReadOnly := True;
  end;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  lv1.WindowProc := FlistViewOldWndProc;
  FListViewOldWndProc  := nil;
end;
{-------------------------------------------------------------------------------
Description: 禁止ListView调整列宽
-------------------------------------------------------------------------------}
procedure TForm1.ListViewNewWndProc(var Msg: TMessage);
var
  hdn: ^THDNotify;
begin
  if Msg.Msg = WM_NOTIFY then
  begin
    hdn := Pointer(Msg.lParam);
    if (hdn.hdr.code = HDN_BeginTrackW) or (hdn.hdr.code = HDN_BeginTrackA) then
      Msg.Result := 1
    else
      FListViewOldWndProc(Msg);
  end
  else
    FListViewOldWndProc(Msg);
end;

{-------------------------------------------------------------------------------
Description: 定义第几个子项为复选框，True值为选中
-------------------------------------------------------------------------------}
const
  SubItemCheck = 2;
{-------------------------------------------------------------------------------
Description: TListView中画出复选框事件
-------------------------------------------------------------------------------}
procedure TForm1.lv1CustomDrawSubItem(Sender: TCustomListView;
  Item: TListItem; SubItem: Integer; State: TCustomDrawState;
  var DefaultDraw: Boolean);
var
  s    : TSize;
  r    : TRect;
  rc   : TRect;
  i    : Integer;
  Dx   : Integer;
  cr   : TColor;
begin
  if (SubItem = SubItemCheck) then
  begin
    DefaultDraw := False;
    rc  := Item.DisplayRect(drBounds);
    Dx  := 0;
    for i := 0 to SubItem - 1 do
      Inc(Dx,Sender.Column[i].Width);
    rc.Left  := rc.Left + Dx;
    rc.Right := rc.Left + Sender.Column[SubItem].Width;
    cr := Sender.Canvas.Brush.Color;
    if Item.Selected and Sender.RowSelect and Sender.Focused then
      Sender.Canvas.Brush.Color := clHighlight
    else
      Sender.Canvas.Brush.Color := clWindow;
    Sender.Canvas.FillRect(rc);
    if cdsFocused in State then
    begin
      DrawFocusRect(Sender.Canvas.Handle,rc);
      Sender.Canvas.FillRect(Rect(rc.Left,rc.Top + 1,rc.Left + 1,rc.Bottom - 1));
    end;
    Sender.Canvas.Brush.Color := cr;
    s.cx := GetSystemMetrics(SM_CXMENUCHECK);
    s.cy := GetSystemMetrics(SM_CYMENUCHECK);
    Dx   := (Sender.Column[SubItem].Width-GetSystemMetrics(SM_CXMENUCHECK)) div 2;
    r.Top    := rc.Top + (rc.Bottom - rc.Top - s.cy) div 2;
    r.Bottom := r.Top + s.cy;
    r.Left   := rc.Left + Dx;
    r.Right  := r.Left + s.cx;
    DrawFrameControl(Sender.Canvas.Handle, r, DFC_BUTTON, IfThen(
      CompareText(Item.SubItems[SubItem-1],'True')=0, DFCS_CHECKED, DFCS_BUTTONCHECK));
  end;
end;
{-------------------------------------------------------------------------------
Description: TListView中子项复选框单击选中事件
-------------------------------------------------------------------------------}
procedure TForm1.lv1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  s    : TSize;
  r    : TRect;
  Rect : TRect;
  i    : Integer;
  Dx   : Integer;
begin
  if (lv1.ItemIndex > -1) and (Shift = [ssleft]) then     //左键点击时
  begin
    Rect  :=lv1.Items[lv1.ItemIndex].DisplayRect(drBounds);
    Dx := 0;
    for i := 0 to SubItemCheck - 1 do
      Inc(Dx,lv1.Column[i].Width);
    Rect.Left  :=Rect.Left + Dx;
    Rect.Right :=Rect.Left + lv1.Column[SubItemCheck].Width;
    s.cx := GetSystemMetrics(SM_CXMENUCHECK);
    s.cy := GetSystemMetrics(SM_CYMENUCHECK);
    Dx   := (lv1.Column[SubItemCheck].Width - GetSystemMetrics(SM_CXMENUCHECK)) div 2;
    r.Top    := Rect.Top + (Rect.Bottom - Rect.Top - s.cy) div 2;
    r.Bottom := r.Top + s.cy;
    r.Left   := Rect.Left + Dx;
    r.Right  := r.Left + s.cx;
    if (x >= r.Left) and (y >= r.Top) and (x <= r.Right) and (y <= r.Bottom)then
    begin   //判断是否点中复选框
      if lv1.Items[lv1.ItemIndex].SubItems.Strings[SubItemCheck - 1] = 'true' then
        lv1.Items[lv1.ItemIndex].SubItems.Strings[SubItemCheck - 1] := 'false'
      else
        lv1.Items[lv1.ItemIndex].SubItems.Strings[SubItemCheck - 1] := 'true';
    end;
  end;
end;
end.

运行结果如下所示：

Delphi 7的ListView自画CheckBox_integer Delphi 7的ListView自画CheckBox_listview_02