Listview 的异步回发不起作用

Question

我有一个包含许多链接按钮的列表视图。目前，当您单击一个按钮时，它会触发一个完整的回发，我想交换它以便它只是部分回发。似乎它应该足够简单，但无论我做什么，我似乎都无法让它工作。似乎我错过了一些明显的东西，但在这一点上，我很难过。

列表视图：

<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" ChildrenAsTriggers="False" runat="server">
<ContentTemplate>
  <section id="basketbox">
    <hgroup class="mainhead">
      <h2>Your basket</h2>
    </hgroup>
    <asp:ListView runat="server" ID="ListView1" OnItemCommand="ListView1_ItemCommand" DataSourceID="SqlDataSource1" DataKeyNames="PartCode">
      <LayoutTemplate>
          <div runat="server" id="itemPlaceholder" ></div>
      </LayoutTemplate>
      <ItemTemplate>
            <h4><%#Eval("Name") %></h4>
            <div class="quantitybox">
              <div class="qtylbl">Qty</div>
              <asp:LinkButton id="QtyDown" CommandArgument='<%#Databinder.Eval(Container.DataItem,"PartCode")%>' CssClass="qtybutton" CommandName="QtyDown" runat="server"><img src="/images/minus.png"></asp:LinkButton>
              <div class="qtybox"><%#Eval("Quantity") %></div>
              <asp:LinkButton id="QtyUp" CommandArgument='<%#Databinder.Eval(Container.DataItem,"PartCode")%>' CssClass="qtybutton" CommandName="QtyUp" runat="server"><img src="/images/plus.png"></asp:LinkButton>
            </div>
      </ItemTemplate>
    </asp:ListView>
  </section>
</ContentTemplate>
<Triggers>
    <asp:AsyncPostBackTrigger ControlID="ListView1" />
</Triggers>
</asp:UpdatePanel>

我尝试过的事情： -ChildrenAsTriggers 设置为 true（没有区别）

-将触发器设置为链接按钮 ID（未找到控件）

-在页面声明中将页面设置为异步（没有区别）

-在列表视图控件上将 ClientIDMode 设置为 AutoID（没有区别）

-向脚本管理器注册一个链接按钮（下面的代码隐藏函数）

Private Sub RegisterPostBackControl()
    For Each item As ListviewItem In  ListView1.Items
        Dim lnkFull As LinkButton = TryCast(item.FindControl("QtyUp"), LinkButton)
        ScriptManager.GetCurrent(Me).RegisterAsyncPostBackControl(lnkFull)
    Next
End Sub

再次：没有区别

我也尝试了其中的大多数组合在一起；这些都没有任何区别。

我还应该尝试什么？

Answer 1

您的 cmets 听起来您需要学习很多才能使用通用处理程序来响应 AJAX 请求。不是这样的，你可能有必要的知识

QtyDown.ashx

<%@ WebHandler Language="C#" Class="Handler" %>

using System;
using System.Web;

public class QtyChangeResponse
{
    public bool Success {get; set;}
    public string Message {get; set;}
}

public class Handler : IHttpHandler
{
    public void ProcessRequest (HttpContext context)
    {
        //pull values from query string
        //update database based on values
        //create response
        var responseObj = new QtyChangeResponse(){Success=true, Message="Qty Updated"};
        context.Response.ContentType="application/json";
        context.Response.Write(JsonConvert.SerializeObject(responseObj));       
    }

    public bool IsReusable
    { get { return false; } }
}

VB版（Telerik自动翻译）

Imports System.Web

Public Class QtyChangeResponse
    Public Property Success() As Boolean
        Get
            Return m_Success
        End Get
        Set
            m_Success = Value
        End Set
    End Property
    Private m_Success As Boolean
    Public Property Message() As String
        Get
            Return m_Message
        End Get
        Set
            m_Message = Value
        End Set
    End Property
    Private m_Message As String
End Class

Public Class Handler
    Implements IHttpHandler
    Public Sub ProcessRequest(context As HttpContext)
        'pull values from query string
        'update database based on values
        'create response
        Dim responseObj = New QtyChangeResponse() With { _
            Key .Success = True, _
            Key .Message = "Qty Updated" _
        }
        context.Response.ContentType = "application/json"
        context.Response.Write(JsonConvert.SerializeObject(responseObj))
    End Sub

    Public ReadOnly Property IsReusable() As Boolean
        Get
            Return False
        End Get
    End Property
End Class

所以这与 Web API 控制器大致相同。

<asp:LinkButton id="QtyDown" CssClass="qtybutton" runat="server" OnClientClick='QtyDown(<%#Databinder.Eval(Container.DataItem,"PartCode")%>); return false;'><img src="/images/minus.png"></asp:LinkButton>

<script type="text/javascript">
function QtyDown(partCode){
    //use your favorite JavaScript library to gather the quantity and PartCode and make a POST call to QtyDown.ashx?qty={quantity}&partcode={partcode)
}
</script>

比 UpdatePanel 更容易支持，错误更少，而且我已经为你做了很多工作。