我写了一个
unit CheckTreeview;
interface
uses
Windows, Messages, SysUtils, Classes, Controls,Commctrl,ComCtrls;
const
TVIS_CHECKED = $2000;
type
TCheckTreeview = class(TTreeView)
private
{ Private declarations }
protected
{ Protected declarations }
procedure CreateParams(var Params: TCreateParams); override;
public
{ Public declarations }
function IsChecked(Node :TTreeNode) :Boolean;
procedure SetChecked(Node :TTreeNode; Checked :Boolean);
published
{ Published declarations }
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('syz_component', [TCheckTreeview]);
end;
{ TCheckTreeview }
procedure TCheckTreeview.CreateParams(var Params: TCreateParams);
begin
inherited;
Params.Style:=Params.Style or TVS_CHECKBOXES;
end;
function TCheckTreeview.IsChecked(Node: TTreeNode): Boolean;
var
TvItem :TTVItem;
begin
TvItem.Mask := TVIF_STATE;
TvItem.hItem := Node.ItemId;
TreeView_GetItem(Node.TreeView.Handle, TvItem);
Result := (TvItem.State and TVIS_CHECKED) = TVIS_CHECKED;
end;
procedure TCheckTreeview.SetChecked(Node: TTreeNode; Checked: Boolean);
var
TvItem :TTVItem;
begin
FillChar(TvItem, SizeOf(TvItem), 0);
with TvItem do begin
hItem := Node.ItemId;
Mask := TVIF_STATE;
StateMask := TVIS_STATEIMAGEMASK;
if Checked then
TvItem.State :=TVIS_CHECKED
else
TvItem.State :=TVIS_CHECKED shr 1;
TreeView_SetItem(Node.TreeView.Handle, TvItem);
end;
end;
end.
