A clean way of generating QueryString parameters for web requests

I was hoping to find a solution built into the framework but didn't. (those methods that are in the framework require to much work to make it simple and clean)

After trying several alternatives I currently use the following extension method: (post a better solution or comment if you have one)

public static class UriExtensions
{
    public static Uri AddQuery(this Uri uri, string name, string value)
    {
        string newUrl = uri.OriginalString;

        if (newUrl.EndsWith("&") || newUrl.EndsWith("?"))
            newUrl = string.Format("{0}{1}={2}", newUrl, name, value);
        else if (newUrl.Contains("?"))
            newUrl = string.Format("{0}&{1}={2}", newUrl, name, value);
        else
            newUrl = string.Format("{0}?{1}={2}", newUrl, name, value);

        return new Uri(newUrl);
    }
}

This extension method makes for very clean redirection and uri manipulation:

Response.Redirect(Request.Url.AddQuery("ProductID", productId).ToString());

// Will generate a URL of www.google.com/search?q=asp.net
var url = new Uri("www.google.com/search").AddQuery("q", "asp.net")

and will work for the following Url's:

"http://www.google.com/somepage"
"http://www.google.com/somepage?"
"http://www.google.com/somepage?OldQuery=Data"
"http://www.google.com/somepage?OldQuery=Data&"

Note that whatever route you use, you should really encode the values - Uri.EscapeDataString should do that for you:

string s = string.Format("http://somesite?foo={0}&bar={1}",
            Uri.EscapeDataString("&hehe"),
            Uri.EscapeDataString("#mwaha"));

What I usually do is just rebuild the querystring. Request has a QueryString collection.

You can iterator over that to get the current (unencoded) parameters out, and just join them together (encoding as you go) with the appropriate separators.

The advantage is that Asp.Net has done the original parsing for you, so you don't need to worry about edge cases such as trailing & and ?s.

I find my way for easy manipulating with get parameters.

public static string UrlFormatParams(this string url, string paramsPattern, params object[] paramsValues)
{
    string[] s = url.Split(new string[] {"?"}, StringSplitOptions.RemoveEmptyEntries);
    string newQueryString = String.Format(paramsPattern, paramsValues);
    List<string> pairs = new List<string>();

    NameValueCollection urlQueryCol = null;
    NameValueCollection newQueryCol = HttpUtility.ParseQueryString(newQueryString);

    if (1 == s.Length)
    {
        urlQueryCol = new NameValueCollection();
    }
    else
    {
        urlQueryCol = HttpUtility.ParseQueryString(s[1]);
    }



    for (int i = 0; i < newQueryCol.Count; i++)
    {
        string key = newQueryCol.AllKeys[i];
        urlQueryCol[key] = newQueryCol[key];
    }

    for (int i = 0; i < urlQueryCol.Count; i++)
    {
        string key = urlQueryCol.AllKeys[i];
        string pair = String.Format("{0}={1}", key, urlQueryCol[key]);
        pairs.Add(pair);
    }

    newQueryString = String.Join("&", pairs.ToArray());

    return String.Format("{0}?{1}", s[0], newQueryString);
}

Use it like

"~/SearchInHistory.aspx".UrlFormatParams("t={0}&s={1}", searchType, searchString)

Check This!!!

// First Get The Method Used by Request i.e Get/POST from current Context
string method = context.Request.HttpMethod;

// Declare a NameValueCollection Pair to store QueryString parameters from Web Request
NameValueCollection queryStringNameValCollection = new NameValueCollection();

if (method.ToLower().Equals("post")) // Web Request Method is Post
{
   string contenttype = context.Request.ContentType;

   if (contenttype.ToLower().Equals("application/x-www-form-urlencoded"))
   {
      int data = context.Request.ContentLength;
      byte[] bytData = context.Request.BinaryRead(context.Request.ContentLength);
      queryStringNameValCollection = context.Request.Params;
   }
}
else // Web Request Method is Get
{
   queryStringNameValCollection = context.Request.QueryString;
}

// Now Finally if you want all the KEYS from QueryString in ArrayList
ArrayList arrListKeys = new ArrayList();

for (int index = 0; index < queryStringNameValCollection.Count; index++)
{
   string key = queryStringNameValCollection.GetKey(index);
   if (!string.IsNullOrEmpty(key))
   {
      arrListKeys.Add(key.ToLower());
   }
}