最简单的c#处理程序输出json格式数据

前台：

<script language="javascript">
function Getson(pid, SelectId) { 
    $.ajax({
        type:"post",
        async:false,
        url:"xx.ashx",
        data:"pid=" + pid,
        dataType:"json",
        success:function(data) {
            var html = "";   
            if (data != "") {
                var temp = eval(data);
                  for (var i = 0; i < temp.length; i++) {
                  html += "<option value='" + temp[i].id + "'>" + temp[i].name + "</option>";
                }
            }
            else {
                html = "<option value='0'>暂无</option>";
            }
   
//   for (var i = 0; i < temp.length; i++) {
//     html += "<option value='" + temp[i].code + "' ";
//     if(temp[i].code==SelectId){
//     html += "selected='selected' ";
//     }
//    html += ">" + temp[i].name + "</option>";
//   }
   
            $("#" + SelectId).html(html);
        }
    });
}
</script>

 

 

ashx处理程序：
using System; 
using System.Web;
using System.Data; 
using System.IO;
using System.Data.SqlClient; 
using mynamespace;

public class Handler : IHttpHandler {
 UseSqlData N =null;
 DataTable ar2 ;   
    public void ProcessRequest (HttpContext context) {
        context.Response.ContentType = "text/plain";       

       //数据库操作 
        N = new  UseSqlData();
        string pid = "0";
      if(context.Request["pid"]!=null&&context.Request["pid"]!=""){
            pid=context.Request["pid"];
         }
  string strSQL="SELECT id,name FROM xxxx where parentID ="+pid+"  order by orderid ";
  
  context.Response.Write("[");
  string tempstr="";//使用stringbufferd最好
  ar2 = N.GetDataTable(strSQL,"f2");
    if(ar2!=null){
         for( int i = 0 ;i < ar2.Rows.Count ;i ++){ 
              tempstr=tempstr+"{"; 
              tempstr=tempstr+"\"id\":\""+ar2.Rows[i][0]+"\",";
              tempstr=tempstr+"\"name\":\""+ar2.Rows[i][1]+"\"";  
              tempstr=tempstr+"},"; 
       }
       }
       if(tempstr!="") tempstr=tempstr.Substring(0,tempstr.Length-1);
      
       context.Response.Write(tempstr); 
        context.Response.Write("]"); 
       
       N =null;
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}

 

还可以C#自带的方法转化json格式