学习 TTreeView [16] - 给 TTreeView 添加复选框 (回复 "丁永其" 的问题)

unit Unit1;

interface

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

type
TForm1 = class(TForm)
TreeView1: TTreeView;
Button1: TButton;
Button2: TButton;
Button3: TButton;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses CommCtrl;

//让 TreeView 带有复选框
procedure TForm1.FormCreate(Sender: TObject);
var
H: HWND;
begin
H := TreeView1.Handle;
SetWindowLong(H, GWL_STYLE, GetWindowLong(H, GWL_STYLE) or TVS_CHECKBOXES);

{下面的代码只是给 TreeView 添加内容}
with TreeView1 do
begin
Align := alLeft;
Items.Add(nil, 'AAA');
Items.Add(nil, 'BBB');
Items.Add(nil, 'CCC');
Items.AddChild(Items[2], '111');
Items.AddChild(Items[2], '222');
Items.AddChild(Items[2], '333');
end;
end;

//列举带有复选框的项
procedure TForm1.Button1Click(Sender: TObject);
var
Node: TTreeNode;
TVI: TTVItem;
begin
for Node in TreeView1.Items do
begin
TVI.mask := TVIF_STATE;
TVI.hItem := Node.ItemId;
TreeView_GetItem(TreeView1.Handle, TVI);
if TVI.state and $2000 = $2000 then
ShowMessage(Node.Text);
end;
end;

//取消所有选中(这是后来补充的, 所以效果图上没有)
procedure TForm1.Button2Click(Sender: TObject);
var
Node: TTreeNode;
TVI: TTVItem;
begin
for Node in TreeView1.Items do
begin
TVI.mask := TVIF_STATE;
TVI.hItem := Node.ItemId;
TVI.stateMask := TVIS_STATEIMAGEMASK;
TVI.state := $2000 shr 1;
TreeView_SetItem(TreeView1.Handle, TVI);
end;
end;

//选中所有(这是后来补充的, 所以效果图上没有)
procedure TForm1.Button3Click(Sender: TObject);
var
Node: TTreeNode;
TVI: TTVItem;
begin
for Node in TreeView1.Items do
begin
TVI.mask := TVIF_STATE;
TVI.hItem := Node.ItemId;
TVI.stateMask := TVIS_STATEIMAGEMASK;
TVI.state := $2000;
TreeView_SetItem(TreeView1.Handle, TVI);
end;
end;

end.