一个AJAX用户名验证问题！请大家帮忙指点下！
后台 CS文件
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class RegisterPage : PageBase
{
UserEntity user = new UserEntity();
protected void Page_Load(object sender, EventArgs e)
{
AjaxPro.Utility.RegisterTypeForAjax(typeof(RegisterPage));
}
[AjaxPro.AjaxMethod]
public string select(string username)
{
string a = "已存在！ ";
string b = "可以使用 ";
// string username= Request.QueryString[ "username "].ToString();
string sql = "select * from BBS where bbsname= ' " + username + " ' ";
DataSet ds = DBAcess.GetDataSet(sql, true);
if (ds.Tables[0].Rows.Count > 0)
{
return a;
}
else
return b;
}
[AjaxPro.AjaxMethod]
public string pwd(string p1, string p2)
{
string a = "一致 ";
string b = "不一致 ";
if (p1 == p2)
{
return a;
}
else
return b;
}
}
前台文件 因为代码较长。我只贴出有关的部分。
<asp:Content ID = "reg " ContentPlaceHolderID = "Registerpage " runat = "server " >
<script language= "javascript " type= "text/javascript ">
function textbox()
{
var username=document.getElementById( " <%#TextBox1.ClientID%> ").value;
RegisterPage.select(username,getGroups_callback } function getGroups_callback(response)
{
document.getElementById( "tb ").value=response.value
// var dt=response.value; alert(dt);
}
</script>
<asp:Panel ID= "Panel1 " runat= "server " Width= "269px " >
<%--个人用户--%>
<table > <tr> <td > <%#Global.GetString( "RegType ")%> </td>
<td style= "width: 158px "> <asp:RadioButtonList ID= "SelectType " runat= "server " RepeatDirection= "Horizontal ">
<asp:ListItem/> <asp:ListItem />
</asp:RadioButtonList> </td>
<td style= "width: 158px ">
</td>
</tr>
<tr> <td> <%#Global.GetString( "LabName ")%> </td> <td style= "width: 158px "> <asp:TextBox ID= "TextBox1 " runat= "server "/> </td>
<td style= "width: 158px "> <input id= "comit " type= "button " value= "检测用户名是否 " onclick= "textbox() "/>
<asp:TextBox ID= "tb " runat= "server "> </asp:TextBox>
</td>
</tr>
现在运行页面后。点击按纽检测用户名老弹出一个对话框说
'document.getElementById() '为空或者不是对象
请大家指点下！谢谢了！
[解决办法]
查看源文件，看 <asp:TextBox ID= "tb " runat= "server "> </asp:TextBox> 这句生成的HTML中，ID是否还为 "tb ".
[解决办法]
var username=document.getElementById( " <%#TextBox1.ClientID%> ").value;
~~~~~~~~~~~~~~~~~~~~~~~~~~`
把这个改成 <%= TextBox1.ClientID %>
[解决办法]
在js中用alert抛出你想查看的值，看其中到底是什么东西，有什么没有取到
js的是比较难调试点
一步步跟下
