c# - 为什么不能选择 DropDownList 项？

Question

当我用FineUI DropDownList实现一棵树的时候。页面源代码如下:

    <form id="form1" runat="server">
    <div>
    <FineUI:PageManager runat="server" id="PageManager1"></FineUI:PageManager>
        <FineUI:SimpleForm ID="SimpleForm1" BodyPadding="5px" runat="server" LabelWidth="150px" Width="550px" EnableCollapse="true"
            ShowBorder="True" Title="Simple Form" ShowHeader="True">
            <Items>
                <FineUI:DropDownList Label="Simulation tree DropDownList" AutoPostBack="false" Required="true" EnableSimulateTree="true"
                    ShowRedStar="true" runat="server" ID="ddlBox">
                </FineUI:DropDownList>
                <FineUI:Button ID="Button1" Text="Show Selected Item" runat="server" OnClick="Button1_Click">
                </FineUI:Button>
                <FineUI:Label runat="server" ID ="result" Label ="select items"></FineUI:Label>
            </Items>
        </FineUI:SimpleForm> 
    </div>
    </form>

在 page_load() 事件中完成 DropDownList 的数据绑定(bind)。事件代码:

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        binddata();
    }
}
public class JQueryFeature
{
    private string _id;
    public string Id
    {
        get { return _id; }
        set { _id = value; }
    }
    private string _name;
    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }
    private int _level;
    public int Level
    {
        get { return _level; }
        set { _level = value; }
    }
    private bool _enableSelect;
    public bool EnableSelect
    {
        get { return _enableSelect; }
        set { _enableSelect = value; }
    }
    public JQueryFeature(string id, string name, int level, bool enableSelect)
    {
        _id = id;
        _name = name;
        _level = level;
        _enableSelect = enableSelect;
    }
    public override string ToString()
    {
        return String.Format("Name:{0}+Id:{1}", Name, Id);
    }
}
private void binddata()
{ 
    List<JQueryFeature> mylist= new List<JQueryFeature>();
    mylist.Add(new JQueryFeature("0", "jQuery", 0, false));
    mylist.Add(new JQueryFeature("1", "core", 1, false));
    mylist.Add(new JQueryFeature("2", "Select", 1, false));
    mylist.Add(new JQueryFeature("3", "Base Select", 2, true));
    mylist.Add(new JQueryFeature("4", "Content Select", 2, true));
    mylist.Add(new JQueryFeature("5", "Property Select", 2, true));
    mylist.Add(new JQueryFeature("6", "Sift", 1, false));
    mylist.Add(new JQueryFeature("7", "Filtration", 2, true));
    mylist.Add(new JQueryFeature("8", "Search", 2, true));
    mylist.Add(new JQueryFeature("9", "Event", 1, false));
    mylist.Add(new JQueryFeature("10", "Page_load", 2, true));
    mylist.Add(new JQueryFeature("11", "Event_deal", 2, true));
    mylist.Add(new JQueryFeature("12", "Event_authorize", 2, true));
    ddlBox.DataTextField = "Name";
    ddlBox.DataValueField = "Id";
    ddlBox.DataSimulateTreeLevelField = "Level";
    ddlBox.DataEnableSelectField = "EnableSelect";
    ddlBox.DataSource = mylist;
    ddlBox.DataBind();
}

当我完成这些代码时。 DropDownList 可以显示数据，但是有一个问题我无法选择列表中的任何项目。我该如何解决这个问题？

Answer 1

设置 DropDownList 的 SelectedValue。在 binddata() 事件的末尾添加此代码:ddlBox.SelectedValue = "3";问题会解决。