Shoot -- I've been having problems with connectivity on my server.
Partial Class CallBack_DB_aspx
Implements System.Web.UI.ICallbackEventHandler
Protected ZipTable As Hashtable
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) _
Handles Me.Load
ZipTable = New Hashtable()
ZipTable.Add("98106", "Seattle")
ZipTable.Add("10270", "New York")
ZipTable.Add("95110", "San Jose")
Dim cbReference As String = Page.GetCallbackEventReference(Me, _
"arg", "GetServerData", "context")
Dim callbackScript As String = ""
callbackScript &= "function CallTheServer(arg, context)"
callbackScript &= vbCrLf & "{"
callbackScript &= vbCrLf & " " & cbReference & ";"
callbackScript &= vbCrLf & "}"
Page.ClientScript.RegisterClientScriptBlock(Me.GetType(), _
"CallTheServer", callbackScript, True)
End Sub
Public Function RaiseCallbackEvent(ByVal eventArgument As String) _
As String Implements _
System.Web.UI.ICallbackEventHandler.RaiseCallbackEvent
Dim city As String
If ZipTable(eventArgument) Is Nothing Then
city = "Not found"
Else
city = ZipTable(eventArgument).ToString()
End If
Return city
End Function
End Class
Here's the page:
<%@ Page Language="VB" AutoEventWireup="false"
CompileWith="CallBack_DB.aspx.vb" ClassName="CallBack_DB_aspx" %>
<html>
<head runat="server">
<script type="text/javascript">
function CityLookup()
{
var zip = document.forms[0].zip.value;
CallTheServer(zip, "");
}
function GetServerData(city, context)
{
document.forms[0].city.value = city;
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<input type="text" id="zip" />
<br />
<button onclick="CityLookup()">Look up city</button>
<br />
<input type="text" id="city" />
</div>
</form>
</body>
</htm>