delphi - 如何在TListView标题列中显示复选框？

Question

我需要在 TListView 的列标题中有一个复选框:

我尝试过以下代码:

with CheckBox1 do
begin
  Parent := ListView1;
  Top := 0;
  Left := 4;
end;

但该复选框并不总是按预期工作。如何在 TListView 标题列中正确创建复选框？

Answer 1

以下代码会将复选框添加到 ListView 的标题中，并显示如何处理它的点击事件。

请注意，自 Windows Vista 起支持以下代码。

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, CommCtrl;

type
  TForm1 = class(TForm)
    ListView1: TListView;
    procedure FormCreate(Sender: TObject);
  private
    HeaderID: Integer;
    procedure WMNotify(var AMessage: TWMNotify); message WM_NOTIFY;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.WMNotify(var AMessage: TWMNotify);
begin
  if AMessage.NMHdr^.idFrom = HeaderID then
    if AMessage.NMHdr^.code = HDN_ITEMSTATEICONCLICK then
      ShowMessage('You have clicked the header check box');

  inherited;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  HeaderHandle: HWND;
  HeaderItem: HD_ITEM;
  HeaderStyle: Integer;
begin
  ListView_SetExtendedListViewStyle(ListView1.Handle, LVS_EX_CHECKBOXES or LVS_EX_FULLROWSELECT);
  HeaderHandle := ListView_GetHeader(ListView1.Handle);
  HeaderStyle := GetWindowLong(HeaderHandle, GWL_STYLE);
  HeaderStyle := HeaderStyle or HDS_CHECKBOXES;
  SetWindowLong(HeaderHandle, GWL_STYLE, HeaderStyle);

  HeaderItem.Mask := HDI_FORMAT;
  Header_GetItem(HeaderHandle, 0, HeaderItem);
  HeaderItem.fmt := HeaderItem.fmt or HDF_CHECKBOX or HDF_FIXEDWIDTH;
  Header_SetItem(HeaderHandle, 0, HeaderItem);

  HeaderID := GetDlgCtrlID(HeaderHandle);
end;

end.