Devexpress treelist 樹形控件 實現帶三種狀態的CheckBox

樹形控件是使用頻率很高的一種控件。對於屬性控件每每須要下面兩個功能

1.TreeList帶有CheckBox，而且節點要有三種狀態（全部的子節點都選中，全部的子節點都沒選擇，一部分子節點選中）。使用 DevXpress的TreeList控件很容易實現這一功能。

設置TreeList.OptionsView.ShowCheckBoxes = true            //是否顯示CheckBox

設置TreeList.OptionsBehavior.AllowIndeterminateCheckState = true;         //設置節點是否有中間狀態，即一部分子節點選中，一部分子節點沒有選中

設置這兩個屬性以後就實現了TreeList帶有CheckBox,而且節點有三種狀態。

2.選中父節點或者子節點相互影響的功能，如選擇父節點選擇全部子節點。綁定TreeList的兩個事件AfterCheckNode和 BeforeCheckNode

實現功能的代碼以下：

        private void treeList1_AfterCheckNode(object sender, DevExpress.XtraTreeList.NodeEventArgs e)
        {
            SetCheckedChildNodes(e.Node, e.Node.CheckState);
            SetCheckedParentNodes(e.Node, e.Node.CheckState);

        }

        private void treeList1_BeforeCheckNode(object sender, DevExpress.XtraTreeList.CheckNodeEventArgs e)
        {
            e.State = (e.PrevState == CheckState.Checked ? CheckState.Unchecked : CheckState.Checked);
        }

        /// <summary>
        /// 設置子節點的狀態
        /// </summary>
        /// <param name="node"></param>
        /// <param name="check"></param>
        private void SetCheckedChildNodes(DevExpress.XtraTreeList.Nodes.TreeListNode node, CheckState check)
        {
            for (int i = 0; i < node.Nodes.Count; i++)
            {
                node.Nodes[i].CheckState = check;
                SetCheckedChildNodes(node.Nodes[i], check);
            }
        }

        /// <summary>        /// 設置父節點的狀態        /// </summary>        /// <param name="node"></param>        /// <param name="check"></param>        private void SetCheckedParentNodes(DevExpress.XtraTreeList.Nodes.TreeListNode node, CheckState check)        {            if (node.ParentNode != null)            {                bool b = false;                CheckState state;                for (int i = 0; i < node.ParentNode.Nodes.Count; i++)                {                    state = (CheckState)node.ParentNode.Nodes[i].CheckState;                    if (!check.Equals(state))                    {                        b = !b;                        break;                    }                }                node.ParentNode.CheckState = b ? CheckState.Indeterminate : check;                SetCheckedParentNodes(node.ParentNode, check);            }        }