json+ashx+ajax简单示例

1.DataTableToJson方法：

    public  string DataTableToJson(DataTable dt)
    {
        StringBuilder jsonBuilder = new StringBuilder();
        jsonBuilder.Append("[");
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            jsonBuilder.Append("{");
            for (int j = 0; j < dt.Columns.Count; j++) 
            {
                jsonBuilder.Append("\"");
                jsonBuilder.Append(dt.Columns[j].ColumnName);
                jsonBuilder.Append("\":\"");
                jsonBuilder.Append(dt.Rows[i][j].ToString());
                jsonBuilder.Append("\","); 
            }
            jsonBuilder.Remove(jsonBuilder.Length - 1, 1);
            jsonBuilder.Append("},");
        }
        jsonBuilder.Remove(jsonBuilder.Length - 1, 1);
        if (jsonBuilder.ToString()!="")
        {
            jsonBuilder.Append("]");
        }
        return jsonBuilder.ToString();
    }

使用context.Response.Write(jsonBuilder.ToString);输出字符串

2.前台<script></script>

    $("#dbtn").click(function(){  
        var txb_name = $('#txb_changeName').val();
        $.ajax({  
               type: "POST",  
               url:"Handler.ashx",  
               data:{name:txb_name}, 
               beforeSend:function(){  
               $("#lb_tips").html("loading");
               },  
               success: function(msg){  
               if(msg!="")
               {
                    var type= eval(msg);
                    var str = "first";
                    for(var i = 0;i<type.length;i++)
                    {
                        str+="<a>"+type[i].membUser+"</a>"
                    }
                    $('#lb_tips').html(str);
               }
               else
               {
                    var notfound="<h2>未找到数据</h2>";
                    $('#lb_tips').html(notfound);
               }
               }  
        });          
    });