ASP.NET中的双向数据绑定

Question

假设我们有一个对象

class Entity
{
    public string ID {get; set;}
    public string Name {get; set;}
}

我想将属性绑定到页面上的两个文本框,如下所示:

<asp:FormView ID="FormView" runat="server">
  <ItemTemplate>
    <asp:textbox ID="TextId" Text='<%# Bind("ID") %>'/>
    <asp:textbox ID="TextId" Text='<%# Bind("Name") %>'/>
  </ItemTemplate>
</asp:FormView>

然后在代码后面写这个

public EntityObject
{
    get { return ViewState["Entity"] as Entity; }
    set { ViewState["Entity"] = value; }
}

protected override void OnInit(EventArgs e)
{
    if (EntityObject== null)
        EntityObject= new EntityObject();

    FormView.DataSource = new[] { EntityObject };
    FormView.DataBind();
    base.OnInit(e);
}

当我在文本框中输入值时,我希望EntityObject在PostBack之后重新加载页面时在属性中包含这些值,但属性始终为null.

Answer 1

遗憾的是,但ASP.NET不支持双向绑定到.net对象......相反,你可以在每个帖子上使用类似"手动绑定"的东西(这里AddIncomeSources是RepeaterControl)

public List<Income> AdditionalIncomeList 
{
    get { return ViewState["AdditionalIncome"] as List<Income>; }
    set { ViewState["AdditionalIncome"] = value; }
} 

foreach (RepeaterItem item in AddIncomeSources.Items)
{
    var amount = (TextBox)item.Controls.Cast<Control>().First(c => c.ID == "Amount");
    var document = (DropDownList)item.Controls.Cast<Control>().First(c => c.ID == "Document");
    AdditionalIncomeList[item.ItemIndex].Amount = amount.Text.ToDouble();
    AdditionalIncomeList[item.ItemIndex].IncomeDocument = document.SelectedValue;
}

AddIncomeSources.DataSource = AdditionalIncomeList;
AddIncomeSources.DataBind();