如何在无刷新页面的情况下实现客户端回调实例

2024-07-21 02:28:46

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经常在网上找各种各样的资料看，来解决某一具有针对性的问题，可是最终发现还是msdn好，可惜大部分没有汉化，而且实例型的资料并不是很多，但不管怎么说msdn还是需要我们认真学习的！
<%@ page language="c#" autoeventwireup="true"
codefile="clientcallback.aspx.cs" inherits="clientcallback" %>

<!doctype html public "-//w3c//dtd xhtml
1.1//en" "http://www.w3.org/tr/xhtml11/dtd/xhtml11.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<script type="text/javascript">
    function lookupstock()
    {
        var lb = document.forms[0].listbox1;
        var product = lb.options[lb.selectedindex].text
        callserver(product, "");
    }

    function receiveserverdata(rvalue)
    {
        results.innertext = rvalue;
    }
</script>
</head>
<body>
<form id="form1" runat="server">
    <div>
      <asp:listbox id="listbox1" runat="server"></asp:listbox>
      <br />
      <br />
      <button >look up stock</button>
      <br />
      <br />
      items in stock: <span id="results"></span>
      <br />
    </div>
</form>
</body>
</html>

1 using system;
2 using system.data;
3 using system.configuration;
4 using system.collections;
5 using system.web;
6 using system.web.security;
7 using system.web.ui;
8 using system.web.ui.webcontrols;
9 using system.web.ui.webcontrols.webparts;
10 using system.web.ui.htmlcontrols;
11
12 public partial class clientcallback : system.web.ui.page,
13      system.web.ui.icallbackeventhandler
14 {
15     protected system.collections.specialized.listdictionary catalog;
16     protected void page_load(object sender, eventargs e)
17     {
18         string cbreference =
19             page.clientscript.getcallbackeventreference(this,
20             "arg", "receiveserverdata", "context");
21         string callbackscript;
22         callbackscript = "function callserver(arg, context)" +
23             "{ " + cbreference + "} ;";
24         page.clientscript.registerclientscriptblock(this.gettype(),
25             "callserver", callbackscript, true);
26
27         catalog = new system.collections.specialized.listdictionary();
28         catalog.add("monitor", 12);
29         catalog.add("laptop", 10);
30         catalog.add("keyboard", 23);
31         catalog.add("mouse", 17);
32
33         listbox1.datasource = catalog;
34         listbox1.datatextfield = "key";
35         listbox1.databind();
36     }
37
38     public string raisecallbackevent(string eventargument)
39     {
40         string returnvalue;
41         if (catalog[eventargument] == null)
42         {
43             returnvalue = "-1";
44         }
45         else
46         {
47             returnvalue = catalog[eventargument].tostring();
48         }
49         return returnvalue;
50     }
51 }