DevExpress TreeListLookupEdit 多选 完整实现

以下是一个完整实现DevExpress TreeListLookupEdit的多选功能的示例代码：

// 初始化TreeListLookupEdit控件
private void InitializeTreeListLookupEdit()
{
    // 设置Properties
    treeListLookupEdit1.Properties.DataSource = GetData();
    treeListLookupEdit1.Properties.DisplayMember = "Text";
    treeListLookupEdit1.Properties.ValueMember = "Value";
    treeListLookupEdit1.Properties.TextEditStyle = DevExpress.XtraEditors.Controls.TextEditStyles.HideText;

    // 设置TreeList
    treeListLookupEdit1TreeList.DataSource = GetData();
    treeListLookupEdit1TreeList.KeyFieldName = "Value";
    treeListLookupEdit1TreeList.ParentFieldName = "ParentValue";
    treeListLookupEdit1TreeList.Columns.Add(new TreeListColumn()
    {
        Caption = "Selected",
        Visible = true,
        Width = 50,
        FieldName = "Selected",
        UnboundType = UnboundColumnType.Boolean,
        OptionsColumn = { AllowEdit = true, ShowCaption = false, ShowInCustomizationForm = false },
        ColumnEdit = new RepositoryItemCheckEdit()
    });
    treeListLookupEdit1TreeList.Columns.Add(new TreeListColumn() { FieldName = "Text", Visible = true });

    // 设置事件
    treeListLookupEdit1TreeList.AfterCheckNode += TreeListLookupEdit1TreeList_AfterCheckNode;
    treeListLookupEdit1.EditValueChanged += TreeListLookupEdit1_EditValueChanged;
}

// 获取数据源
private DataTable GetData()
{
    DataTable dt = new DataTable();
    dt.Columns.Add("Value", typeof(int));
    dt.Columns.Add("Text", typeof(string));
    dt.Columns.Add("ParentValue", typeof(int));
    dt.Columns.Add("Selected", typeof(bool));

    dt.Rows.Add(1, "Node 1", 0, false);
    dt.Rows.Add(2, "Node 1.1", 1, false);
    dt.Rows.Add(3, "Node 1.2", 1, false);
    dt.Rows.Add(4, "Node 1.2.1", 3, false);
    dt.Rows.Add(5, "Node 2", 0, false);
    dt.Rows.Add(6, "Node 2.1", 5, false);
    dt.Rows.Add(7, "Node 2.2", 5, false);

    return dt;
}

// TreeList的AfterCheckNode事件
private void TreeListLookupEdit1TreeList_AfterCheckNode(object sender, NodeEventArgs e)
{
    e.Node.SetValue("Selected", e.Node.CheckState == CheckState.Checked);
    CheckChildNodes(e.Node, e.Node.CheckState);
    CheckParentNodes(e.Node.ParentNode);
}

// 递归勾选或取消勾选子节点
private void CheckChildNodes(TreeListNode node, CheckState state)
{
    foreach (TreeListNode childNode in node.Nodes)
    {
        childNode.CheckState = state;
        childNode.SetValue("Selected", state == CheckState.Checked);
        CheckChildNodes(childNode, state);
    }
}

// 递归勾选或取消勾选父节点
private void CheckParentNodes(TreeListNode node)
{
    if (node == null)
    {
        return;
    }

    bool allChecked = true;
    bool anyChecked = false;
    foreach (TreeListNode childNode in node.Nodes)
    {
        if (!(bool)childNode.GetValue("Selected"))
        {
            allChecked = false;
        }
        else
        {
            anyChecked = true;
        }
    }
    if (allChecked)
    {
        node.CheckState = CheckState.Checked;
    }
    else if (anyChecked)
    {
        node.CheckState = CheckState.Indeterminate;
    }
    else
    {
        node.CheckState = CheckState.Unchecked;
    }
    node.SetValue("Selected", node.CheckState == CheckState.Checked);
    CheckParentNodes(node.ParentNode);
}

// TreeListLookupEdit的EditValueChanged事件
private void TreeListLookupEdit1_EditValueChanged(object sender, EventArgs e)
{
    List<string> selectedValues = new List<string>();
    foreach (TreeListNode node in treeListLookupEdit1TreeList.Nodes)
    {
        if ((bool)node.GetValue("Selected"))
        {
            selectedValues.Add(node.GetValue("Value").ToString());
        }
        AddSelectedNodes(node, selectedValues);
    }
    textEdit1.Text = string.Join(",", selectedValues);
}

// 递归添加选中的节点
private void AddSelectedNodes(TreeListNode node, List<string> selectedValues)
{
    foreach (TreeListNode childNode in node.Nodes)
    {
        if ((bool)childNode.GetValue("Selected"))
        {
            selectedValues.Add(childNode.GetValue("Value").ToString());
        }
        AddSelectedNodes(childNode, selectedValues);
    }
}

通过以上实现，就可以在DevExpress TreeListLookupEdit控件中实现多选功能，并且支持父子节点的联动勾选，用户可以通过勾选复选框来选择多个节点，选择的节点对应的数据将会以逗号分隔的字符串形式显示在另一个TextEdit控件中。