C# 模型绑定webform TryUpdateModel不工作

我在webform中有一个简单的formview和简单的modelbinding：

描述：

说明：

在代码中：

 Models.Model1Container _db = new Models.Model1Container();

    protected void Page_Load(object sender, EventArgs e)
    {
        bindEvents();
        lblResult.ForeColor = System.Drawing.Color.Green;
        lblResult.Text = "";
        if (!IsPostBack)
        {
        }
        else
        {

        }

    }

    private void bindEvents()
    {
       frm.ItemUpdated += frm_ItemUpdated;

    }

    void frm_ItemUpdated(object sender, FormViewUpdatedEventArgs e)
    {
        if (e.Exception == null)
        {
            lblResult.ForeColor = System.Drawing.Color.Green;
            lblResult.Text = "done!";
        }
        else
        {
            lblResult.ForeColor = System.Drawing.Color.Red;
            lblResult.Text = "error:" + e.Exception.Message;
            e.KeepInEditMode = true;
        }


    }


    public SabaDoor2.Models.Content frm_GetItem([System.Web.ModelBinding.QueryString("Id")]int? Id)
    {
        return _db.Contents.Find(Id);
    }

    // The id parameter name should match the DataKeyNames value set on the control
    public void frm_UpdateItem(int Id)
    {
        SabaDoor2.Models.Content item = null;
        item = _db.Contents.Find(Id);
        if (item == null)
        {
            // The item wasn't found
            ModelState.AddModelError("", String.Format("Item with id {0} was not found", Id));
            return;
        }
       var result =    TryUpdateModel(item);


        if (ModelState.IsValid)
        {
            _db.SaveChanges();

        }
    }


    public override void Dispose()
    {
        _db.Dispose();
        base.Dispose();
    }

tryUpdateModel返回true，但my modeldescription字段未更新 ：

我发现了逻辑错误： 我必须初始化BindItem.Name属性而不是item.Name

---

啊，谢谢你！关于asp:FormView和数据绑定的例子并不多。

Text='<%# BindItem.Description %>'