如何显示TListView的标题列复选框？ [英] How to show a check box in TListView header column?

问题描述

我需要有一个复选框中的TListView的列标题：

I need to have a check box in a column header of a TListView:

我曾尝试以下code：

I have tried the following code:

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

但预期该复选框并不总是工作。我怎样才能正确地创建TListView的标题列复选框？

but the check box doesn't always work as expected. How can I properly create a check box in TListView header column ?

推荐答案

以下code将添加复选框列表视图的标题和说明如何处理点击事件吧。结果

The following code will add the check box to the list view's header and shows how to handle the click event for it.

的 请注意，因为Windows Vista中的以下code是支持的。的

Please note, that the following code is supported since Windows Vista.

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.

结果

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