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HttpUtility.ParseQueryString Method (String)

Note: This method is new in the .NET Framework version 2.0.

Parses a query string into a NameValueCollection using UTF8 encoding.

Namespace: System.Web
Assembly: System.Web (in system.web.dll)

public static NameValueCollection ParseQueryString (
	string query
public static NameValueCollection ParseQueryString (
	String query
public static function ParseQueryString (
	query : String
) : NameValueCollection



The query string to parse.

Return Value

A NameValueCollection of query parameters and values.

Exception typeCondition


query is a null reference (Nothing in Visual Basic).

The ParseQueryString method uses UTF8 format to parse the query string In the returned NameValueCollection, URL-encoded characters are decoded and multiple occurrences of the same query string parameter are listed as a single entry with a comma separating each value.

The following code example demonstrates how to use the ParseQueryString method. Multiple occurrences of the same query string variable are consolidated in one entry of the returned NameValueCollection.

<%@ Page Language="C#"%>

<script runat="server">

  protected void Page_Load(object sender, EventArgs e)
    String currurl = HttpContext.Current.Request.RawUrl;
    String querystring = null ;

    // Check to make sure some query string variables
    // exist and if not add some and redirect.
    int iqs = currurl.IndexOf('?');
    if (iqs == -1)
      String redirecturl = currurl + "?var1=1&var2=2+2%2f3&var1=3";
      Response.Redirect(redirecturl, true); 
    // If query string variables exist, put them in
    // a string.
    else if (iqs >= 0)
      querystring = (iqs < currurl.Length - 1) ? currurl.Substring(iqs + 1) : String.Empty;
    // Parse the query string variables into a NameValueCollection.
    NameValueCollection qscoll = HttpUtility.ParseQueryString(querystring);
    // Iterate through the collection.
    StringBuilder sb = new StringBuilder("<br>");
    foreach (String s in qscoll.AllKeys)
      sb.Append(s + " - " + qscoll[s] + "<br>");
    // Write the result to a label.
    ParseOutput.Text = sb.ToString();


<head runat="server">
    <title>HttpUtility ParseQueryString Example</title>
    <form runat="server">
      Query string variables are:
      <asp:Label  id="ParseOutput"
                  runat="server" />

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0