总结：客户端与服务器端使用正则增加URL参数的方法

#region URL参数操作
/// <summary>
/// URL参数操作
/// </summary>
public class UrlPageHelper
{
/// <summary>
/// 以正则表达式方式增加URL参数
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
/// <returns></returns>
public static string AddUrlParm(string key, string value)
{
string Url = HttpContext.Current.Request.RawUrl;
Url = Regex.Replace(Url + "&", @"(.*)(\?|&)" + key + "=[^&]+?(&)(.*)", "$1$2$4", RegexOptions.IgnoreCase);
Url = Url.Remove(Url.Length - 1);
if (Url.Contains('?'))
{
Url = string.Format("{0}&{1}={2}", Url, key, value);
}
else
{
Url = string.Format("{0}?{1}={2}", Url, key, value);
}
return Url;
}
}
#endregion

/**
* 添加URL参数
* @param string $url   原URL
* @param string $key   键
* @param string $value 值
* @return string       新URL
*/
private function add_querystring_var($key, $value) {
$url = $this->url;
$url=preg_replace('/(.*)(\?|&)'.$key.'=[^&]+?(&)(.*)/i','$1$2$4',$url.'&');
$url=substr($url,0,-1);
if(strpos($url,'?') === false){
return ($url.'?'.$key.'='.$value);
} else {
return ($url.'&'.$key.'='.$value);
}
}

(function ($) {
$.extend({
Request: function (m) {
var sValue = location.search.match(new RegExp("[\?\&]" + m + "=([^\&]*)(\&?)", "i"));
return sValue ? sValue[1] : sValue;
},
UrlUpdateParams: function (url, name, value) {
var r = url;
if (r != null && r != 'undefined' && r != "") {
value = encodeURIComponent(value);
var reg = new RegExp("(^|)" + name + "=([^&]*)(|$)");
var tmp = name + "=" + value;
if (url.match(reg) != null) {
r = url.replace(eval(reg), tmp);
}
else {
if (url.match("[\?]")) {
r = url + "&" + tmp;
} else {
r = url + "?" + tmp;
}
}
}
return r;
}

});
})(jQuery);

$.UrlUpdateParams(window.location.href, "order", "111")