简单的AJAX获取数据库表数据

A.aspx页面放一个dropdownlist，在A.aspx.cs添加： this.drpSchool.Attributes.Add("onchange", "load(this.options[this.selectedIndex].value)");

在A.aspx页面添加如下脚本：

function load(state){

var oHttpReq = new ActiveXObject("MSXML2.XMLHTTP");
var oDoc = new ActiveXObject("MSXML2.DOMDocument");

oHttpReq.open("POST", "../B.aspx?state="+state, false);

oHttpReq.send("");
result = oHttpReq.responseText;
oDoc.loadXML(result);

 document.all("DropDownList2 ").length=0;//清空原来绑定的值
items1 = oDoc.selectNodes("//NewDataSet/Table/dtid");
items2 = oDoc.selectNodes("//NewDataSet/Table/dtname");

var itemsLength=items1.length;
　　for(i=0;i<itemsLength;i++)

//将小类的类名和编号赋予DropDownList2
　　{
　
　　var newOption = document.createElement("OPTION");
　　newOption.text=items2[i].text;
　　newOption.value=items1[i].text;
　　drp2.options.add(newOption);
　　//　newOption.value=6;
　
　　}

 

}

 

B.aspx.cs页面：

if (Request.QueryString["state"] != null && Request.QueryString["state"].ToString() != "")
        {

            try
            {
                int shengNo = int.Parse(Request["state"].ToString());
                // int shengNo = 1;

                DataSet ds = new DataSet();
                db dbb = new db();
                ds = dbb.GetDataSet(SQL语句);

              if (ds.Tables[0].Rows.Count > 0)
                {
                    XmlTextWriter writer = new XmlTextWriter(Response.OutputStream, Encoding.UTF8);
                    writer.Formatting = Formatting.Indented;
                    writer.Indentation = 4;
                    writer.IndentChar = ' ';
                    writer.WriteStartDocument();
                    ds.WriteXml(writer);
                    writer.Flush();
                    Response.End();
                    writer.Close();
              }
            }
            catch { }
    }