//1.引用单元

 uses Commctrl ;

 //2.定义私有过程

   procedure tvToggleCheckbox(TreeView: TTreeView;Node: TTreeNode;isclick:boolean =false);

   procedure SetChecked(Node: TTreeNode; Checked: Boolean);

   function IsChecked(Node: TTreeNode): Boolean; 

 //3.过程体代码

 //检查某个节点是否被 选中

 function TForm1.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;

 //让 某个节点被 选中

 procedure TForm1.SetChecked(Node: TTreeNode; Checked: Boolean);

 var

 TvItem :TTVItem;

 begin

   FillChar(TvItem, SizeOf(TvItem), );

   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 ;

     TreeView_SetItem(Node.TreeView.Handle, TvItem);

   end;

 end;

 // 对节点中所有 子节点 都 选中或 未选中 状态

 procedure TForm1.tvToggleCheckbox(TreeView: TTreeView;

 Node: TTreeNode ;isclick :boolean=false);

 var CurNode, ParentNode, GrandSonNode,sonNode: TTreeNode;

 flg1: boolean;

 begin

   CurNode :=node;

   with TreeView do

   begin

     if IsChecked(CurNode) then //

     begin

       sonNode := CurNode.GetFirstChild; //遍历子树,选中 则子节点 全部 为选中；

       while sonNode<>nil do

       begin

         SetChecked(sonNode, true);

         tvToggleCheckbox(TreeView,sonNode,true);

         sonNode := sonNode.GetNextSibling;

       end;

       ParentNode:= CurNode.Parent; //父；

       if ParentNode<>nil then

       begin

         if not isChecked(parentNode) then

         begin

           GrandSonNode := ParentNode.GetFirstChild; //遍历子树；

           flg1 := false;

           while GrandSonNode<>nil do

           begin

             if (not IsChecked(GrandSonNode)) then //true,有未选中

             flg1 := true;

             if flg1 then //已有、退出loop;

             GrandSonNode := nil

             else

             GrandSonNode := GrandSonNode.GetNextSibling;

           end;

           SetChecked(ParentNode, not flg1);

           tvToggleCheckbox(TreeView,ParentNode,false);

         end;

       end; // end parentNode 不等于空

     end

     else if not IsChecked(CurNode) then

     begin

       ParentNode := CurNode.Parent; //父；

       if ParentNode<>nil then

       begin

         if isChecked(parentNode) then

         begin

           SetChecked(ParentNode, false);

           tvToggleCheckbox(TreeView,ParentNode);

         end;

       end; //end parentnode

       if (isclick) then

       begin

         sonNode := CurNode.GetFirstChild; //遍历子树,未选中 则子节点 全部 为未选中；

         while sonNode<>nil do

         begin

           SetChecked(sonNode, false);

           tvToggleCheckbox(TreeView,sonNode,true);

           sonNode := sonNode.GetNextSibling;

         end;

       end;

     end;

   end;

 end;

 //4.点击连选处理

 procedure TForm1.TreeView1Click(Sender: TObject);

 var

   P:TPoint;

   treenode :TTreeNode;

 begin

   GetCursorPos(P);

   P := TreeView1.ScreenToClient(P);

   if (htOnStateIcon in TreeView1.GetHitTestInfoAt(P.X,P.Y)) then

   begin

     treenode := TreeView1.GetNodeAt(P.X,P.Y);

     tvToggleCheckbox(TreeView1,treenode ,true);

   end;

 end;

 //5.生成节点

 procedure TForm1.FormCreate(Sender: TObject);

 begin

   //仅仅这一句话就能让treeview 显示复选框

   SetWindowLong(TreeView1.Handle, GWL_STYLE, GetWindowLong(TreeView1.Handle, GWL_STYLE) or $);

 //  SetWindowLong(H, GWL_STYLE, GetWindowLong(H, GWL_STYLE) or TVS_CHECKBOXES);  //这名同上一个意思

   {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[], '');

      Items.AddChild(Items[], '');

      Items.AddChild(Items[], '');

   end;

 end;

 //6.查看是否选中

 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 $ = $ then

       ShowMessage(Node.Text);

   end;

 end;