HttpUtility.ParseQueryString HttpUtility.ParseQueryString HttpUtility.ParseQueryString HttpUtility.ParseQueryString Method

Definition

Parses a query string into a NameValueCollection.

Overloads

ParseQueryString(String) ParseQueryString(String) ParseQueryString(String) ParseQueryString(String)

Parses a query string into a NameValueCollection using UTF8 encoding.

ParseQueryString(String, Encoding) ParseQueryString(String, Encoding) ParseQueryString(String, Encoding)

Parses a query string into a NameValueCollection using the specified Encoding.

ParseQueryString(String) ParseQueryString(String) ParseQueryString(String) ParseQueryString(String)

Parses a query string into a NameValueCollection using UTF8 encoding.

public:
 static System::Collections::Specialized::NameValueCollection ^ ParseQueryString(System::String ^ query);
public static System.Collections.Specialized.NameValueCollection ParseQueryString (string query);
static member ParseQueryString : string -> System.Collections.Specialized.NameValueCollection
Public Shared Function ParseQueryString (query As String) As NameValueCollection
Parameters
query
String String String String

The query string to parse.

Returns
Exceptions

Examples

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#"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<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();

  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>HttpUtility ParseQueryString Example</title>
</head>
<body>
    <form id="form1" runat="server">
      Query string variables are:
      <asp:Label  id="ParseOutput"
                  runat="server" />
    </form>
</body>
</html>
<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

    Dim currurl As String = HttpContext.Current.Request.RawUrl
    Dim querystring As String = Nothing
    
    ' Check to make sure some query string variables
    ' exist and if not add some and redirect.
    Dim iqs As Int32 = currurl.IndexOf("?".ToCharArray())
    If (iqs = -1) Then
      
      Dim redirecturl As String = currurl & "?var1=1&var2=2+2%2f3&var1=3"
      Response.Redirect(redirecturl, True)
      
      ' If query string variables exist, put them in
      ' a string.
    ElseIf (iqs >= 0) Then
      
      If (iqs < currurl.Length - 1) Then
        querystring = currurl.Substring(iqs + 1)
      End If
          
    End If

    ' Parse the query string variables into a NameValueCollection.
    Dim qscoll As NameValueCollection = HttpUtility.ParseQueryString(querystring)
    
    ' Iterate through the collection.
    Dim sb As New StringBuilder("<br />")
    For Each s As String In qscoll.AllKeys
      
      sb.Append(s & " - " & qscoll(s) & "<br />")
    
    Next s
    
    ' Write the result to a label
    ParseOutput.Text = sb.ToString()
    
  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>HttpUtility ParseQueryString Example</title>
</head>
<body>
    <form id="Form1" runat="server">
      Query string variables are:
      <asp:Label  id="ParseOutput"
                  runat="server" />
    </form>
</body>
</html>

Remarks

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.

Important

The ParseQueryString method uses query strings that might contain user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

See Also

ParseQueryString(String, Encoding) ParseQueryString(String, Encoding) ParseQueryString(String, Encoding)

Parses a query string into a NameValueCollection using the specified Encoding.

public:
 static System::Collections::Specialized::NameValueCollection ^ ParseQueryString(System::String ^ query, System::Text::Encoding ^ encoding);
public static System.Collections.Specialized.NameValueCollection ParseQueryString (string query, System.Text.Encoding encoding);
static member ParseQueryString : string * System.Text.Encoding -> System.Collections.Specialized.NameValueCollection
Parameters
query
String String String String

The query string to parse.

encoding
Encoding Encoding Encoding Encoding

The Encoding to use.

Returns
Exceptions

Remarks

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.

Important

The ParseQueryString method uses query strings that might contain user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

See Also

Applies to