学步园

TreeList控件可以同时显示树结构和其他数据列，即在一个列上建立父子关系展开或收缩，同时还可以显示其他列的内容。

在TreeList中同时引入了
Node和 Columns概念,
第一列为树结构,
其余列为数据列,
任何列都可作为树结构列(即拖动到第一列)显示

1.实现多级树－－－数据源绑定

   在TreeList里添加要显示列（第一列为树结构，其他列为数据列），并指定FieldName为数据库列名

   指定KeyFieldName属性为主键，ParentFieldName属性为树状分组列。注意
ParentFieldName指定的列如果为空值，树状可能会混乱（只有一个根结点，其他为此节点的子结点）

   用TreeList.DataSource =  DataTable 绑定数据即可

（以下内容为转载）多选框的三种状态

树形控件是使用频率很高的一种控件。对于属性控件往往需要下面两个功能

1.TreeList带有CheckBox，并且节点要有三种状态（所有的子节点都选中，所有的子节点都没选择，一部分子节点选中）。使用DevXpress的TreeList控件很容易实现这一功能。

设置TreeList.OptionsView.ShowCheckBoxes = true            //是否显示CheckBox

设置TreeList.OptionsBehavior.AllowIndeterminateCheckState = true;         //设置节点是否有中间状态，即一部分子节点选中，一部分子节点没有选中

设置这两个属性之后就实现了TreeList带有CheckBox,并且节点有三种状态。

2.选中父节点或者子节点相互影响的功能，如选择父节点选择所有子节点。绑定TreeList的两个事件AfterCheckNode和BeforeCheckNode

实现功能的代码如下：

        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>
        /// 设置子节点的状态
        /// </summary>
        /// <param name="node"></param>
        /// <param name="check"></param>
         private void SetCheckedChildNodes(TreeListNode node, CheckState check)
        {
            for (int i = 0; i < node.Nodes.Count; i++)
            {
                node.Nodes[i].CheckState = check;
                SetCheckedChildNodes(node.Nodes[i], check);
            }
        }

        /// <summary>
        /// 设置父节点的状态
        /// </summary>
        /// <param name="node"></param>
        /// <param name="check"></param>
        private void SetCheckedParentNodes(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);
            }
        }

VB.net语言代码如下

    Private Sub trlContact_AfterCheckNode(ByVal sender As System.Object, ByVal e As DevExpress.XtraTreeList.NodeEventArgs) Handles trlContact.AfterCheckNode
        SetCheckedChildNodes(e.Node, e.Node.CheckState)
        SetCheckedParentNodes(e.Node, e.Node.CheckState)
    End Sub
    '设置子结点的状态
    Private Sub SetCheckedChildNodes(ByVal node As TreeListNode, ByVal check As CheckState)
        
        For i As Integer = 0 To node.Nodes.Count - 1
            node.Nodes(i).CheckState = check
            SetCheckedChildNodes(node.Nodes(i), check)
        Next
    End Sub
    '设置父结点的状态
    Private Sub SetCheckedParentNodes(ByVal node As TreeListNode, ByVal check As CheckState)
        If node.ParentNode Is Nothing = False Then
            Dim b As Boolean = False
            Dim state As CheckState
            For i As Integer = 0 To node.ParentNode.Nodes.Count - 1
                state = node.ParentNode.Nodes(i).CheckState
                If check.Equals(state) = False Then
                    b = Not b
                    Exit For
                End If
            Next

            If b Then
                node.ParentNode.CheckState = CheckState.Indeterminate
            Else
                node.ParentNode.CheckState = check
            End If

            SetCheckedParentNodes(node.ParentNode, check)
        End If
    End Sub


    Private Sub trlContact_BeforeCheckNode(ByVal sender As System.Object, ByVal e As DevExpress.XtraTreeList.CheckNodeEventArgs) Handles trlContact.BeforeCheckNode

        If e.PrevState = CheckState.Checked Then
            e.State = CheckState.Unchecked
        Else
            e.State = CheckState.Checked
        End If

    End Sub

效果如图