Url Manipulation v2 (C#)

Made some improvements to the previous UrlQuery class (July 22nd, 2004). It now has a shorter way of assigning QueryString parameters:

MyQuery = new UrlQuery();
// add another parameter (or replace existing one)
MyQuery["myparam"] = "myval";
Trace.Write(MyQuery["myparam"]); // returns 'myval'
// remove parameter
MyQuery["myparam"] = null; // or string.Empty
Trace.Write(MyQuery["myparam"]); // returns ''

UrlQuery class code:

public class UrlQuery
{
	/// <summary>
	/// Base on current page
	/// </summary>
	public UrlQuery()
	{
		this.url = HttpContext.Current.Request.Url.AbsolutePath;
	}
	/// <summary>
	/// Base on other page
	/// </summary>
	/// <param name="value">The url of the page to reference, i.e.: '/path/to/folder/page.aspx?param1=1&param2=2'</param>
	public UrlQuery(string value)
	{
		int q = value.IndexOf('?');
		if (q != -1)
		{
			this.url = value.Substring(0, q);
			this.queryString = NameValueCollection(value);
		}
		else
		{
			this.url = value;
		}
	}
	/// <summary>
	/// Get and set Url parameters
	/// </summary>
	public string this[string param]
	{
		get
		{
			return this.Get(param);
		}
		set
		{
			this.Set(param,value);
		}
	}

	private string url;
	/// <summary>
	/// The Url of the page, without QueryString
	/// </summary>
	/// <value>/path/to/folder/page.aspx</value>
	public string Url
	{
		get
		{
			return this.url;
		}
	}
	/// <summary>
	/// Returns the virtual folder the page is in
	/// </summary>
	/// <value>/path/to/folder/</value>
	public string VirtualFolder
	{
		get
		{
			return this.Url.Substring(0, Url.LastIndexOf("/") + 1);
		}
	}
	/// <summary>
	/// The AbsoluteUri
	/// </summary>
	/// <value>page.aspx?param1=1&param2=2</value>
	public string AbsoluteUri
	{
		get
		{
			return this.Url + this.Get();
		}
	}
	private NameValueCollection queryString;
	/// <summary>
	/// Get the QueryString for the page
	/// </summary>
	public NameValueCollection QueryString
	{
		get
		{
			if (this.queryString != null)
			{
				return this.queryString;
			}
			else
			{
				this.queryString = new NameValueCollection(HttpContext.Current.Request.QueryString);
				return this.queryString;
			}
		}
	}
	/// <summary>
	/// Get the QueryString
	/// </summary>
	/// <returns>String in the format ?param1=1&param2=2</returns>
	public string Get()
	{
		string query = "";
		if (this.QueryString.Count != 0)
		{
			query = "?";
			for (int i = 0; i <= this.QueryString.Count - 1; i++)
			{
				if (i != 0)
				{
					query += "&";
				}
				query += this.QueryString.GetKey(i) + "=" + this.QueryString.Get(i);
			}
		}
		return query;
	}
	/// <summary>
	/// Get parameter from QueryString
	/// </summary>
	/// <param name="param">Parameter to get</param>
	/// <returns>Parameter Value</returns>
	public string Get(string param)
	{
		return this.QueryString[param];
	}
	/// <summary>
	/// Set QueryString parameter
	/// </summary>
	/// <param name="param">Parameter to set</param>
	/// <param name="value">Value of parameter</param>
	public void Set(string param, string value)
	{
		if (param != string.Empty)
		{
			if (value == string.Empty || value == null)
			{
				this.QueryString.Remove(param);
			}
			else
			{
				this.QueryString[param] = value;
			}
		}
	}
	/// <summary>
	/// Convert QueryString string to NameValueCollection
	/// http://groups.google.co.uk/groups?hl=en&lr=&ie=UTF-8&safe=off&selm=uyMZ2oaZDHA.652%40tk2msftngp13.phx.gbl
	/// </summary>
	public static NameValueCollection NameValueCollection(string qs)
	{
		NameValueCollection nvc = new NameValueCollection();
		//strip string data before the question mark
		qs = qs.IndexOf('?') > 0 ? qs.Remove(0, qs.IndexOf('?') + 1) : qs;
		Array sqarr = qs.Split("&".ToCharArray());
		for (int i = 0; i < sqarr.Length; i++)
		{
			string[] pairs = sqarr.GetValue(i).ToString().Split("=".ToCharArray());
			nvc.Add(pairs[0], pairs[1]);
		}
		return nvc;
	}
	/// <summary>
	/// Copies a form paramater to the QueryString
	/// </summary>
	/// <param name="param">Form Parameter</param>
	public void FormToQuery(string param)
	{

		this.Set(param, HttpContext.Current.Request.Form[param]);
	}
}