xmlHttpRequest 以Post方式发数据到Asp.net页,在gb2312编码下的解决办法

   首先xmlHttpRequest 使用Post时,需要对数据进行编码,在客户端一般使用js中的encodeURIComponent

 在web.config中指定了gb2312编码后,在aspx页面中如果直接使用 Request[xxx]那么结果将会出现乱码,

原因是asp.net系统使用gb2312编码对上传的数据进行解码还原,而encodeURIComponent编码是按uft-8来的.

 为了避免这个问题,我们需要见xmlHttpRequest发送上来的原始数据(字节)按utf-8进行解码处理,

方式一

 代码如下

 浏览器端(js):

function myXMLHttpRequest(){
 var xmlHttp = false;
 try {
  xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
 } catch (e) {
  try {
   xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
  } catch (e2) {
   xmlHttp = false;
  }
 }
 if (!xmlHttp && typeof XMLHttpRequest != 'undefined') {
  xmlHttp = new XMLHttpRequest();
 }
 return xmlHttp;
}

 var xmlHttp=myXMLHttpRequest();
  content = "user="+encodeURIComponent("大发啊个啊按时法米]]吗吗吗*-234^342942023&^+\\");
  content +="&data=" +encodeURIComponent("到这里结束了!");
  xmlHttp.Open("POST", "doc.aspx", false);
  xmlHttp.setRequestHeader("Content-Length",content.length);
  xmlHttp.setRequestHeader("CONTENT-TYPE","application/x-www-form-urlencoded");
  xmlHttp.Send(content);

 服务器端(asp.net)

        Byte[] bytes= Request.BinaryRead(Request.ContentLength);
        NameValueCollection req= FillFromEncodedBytes(bytes, Encoding.UTF8);
        Response.Write(req["User"]);

其中FillFromEncodedBytes定义如下(这个是ms内部代码,通过reflector 获得,作用就是根据url编码将字段跟数据分解出来)

略有改动

    private NameValueCollection FillFromEncodedBytes(byte[] bytes, Encoding encoding)
    {
        NameValueCollection _form = new NameValueCollection();
       
        int num = (bytes != null) ? bytes.Length : 0;
        for (int i = 0; i < num; i++)
        {
            string str;
            string str2;
            int offset = i;
            int num4 = -1;
            while (i < num)
            {
                byte num5 = bytes[i];
                if (num5 == 0x3d)
                {
                    if (num4 < 0)
                    {
                        num4 = i;
                    }
                }
                else if (num5 == 0x26)
                {
                    break;
                }
                i++;
            }
            if (num4 >= 0)
            {
                str = HttpUtility.UrlDecode(bytes, offset, num4 - offset, encoding);
                str2 = HttpUtility.UrlDecode(bytes, num4 + 1, (i - num4) - 1, encoding);
            }
            else
            {
                str = null;
                str2 = HttpUtility.UrlDecode(bytes, offset, i - offset, encoding);
            }
            _form.Add(str, str2);
            if ((i == (num - 1)) && (bytes[i] == 0x26))
            {
                _form.Add(null, string.Empty);
            }
        }
        return _form;
    }

 参考代码:https://files.cnblogs.com/wdfrog/xmlhttp.rar

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方式二,使用GET方式发来的请求,上面(方式一)的每个字段也可以使用下面方式进行转换
客户端:(使用Utf-8编码方式)
/services/regServices.aspx?username='+encodeURI(un.value)
服务端:(默认情况下,Request["xxx"]使用gb2312进行UrlDecode处理,所以将结果按gb2312 UrlEncode,后再使用utf-8进行UrlDecode)
    string data1 = Util.GetQ("username", "");
        string data2= HttpUtility.UrlEncode(data1, Encoding.GetEncoding("GB2312"));
        string username = HttpUtility.UrlDecode(data2, Encoding.UTF8);

方式三,处理方式类似第一种,因为要获取的Get,中的Query

        IServiceProvider provider = (IServiceProvider)HttpContext.Current;
        HttpWorkerRequest wr= provider.GetService(typeof(HttpWorkerRequest)) as HttpWorkerRequest;
        byte[] bytes = wr.GetQueryStringRawBytes();
        NameValueCollection req = FillFromEncodedBytes(bytes, Encoding.UTF8);
        string u = req["username"];