HttpUtility.ParseQueryString Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Parses a query string into a NameValueCollection.
Overloads
| ParseQueryString(String) |
Parses a query string into a NameValueCollection using UTF8 encoding. |
| ParseQueryString(String, Encoding) |
Parses a query string into a NameValueCollection using the specified Encoding. |
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.NameValueCollectionPublic Shared Function ParseQueryString (query As String) As NameValueCollectionParameters
- query
- String
The query string to parse.
Returns
A NameValueCollection of query parameters and values.
Exceptions
query is null.
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
Applies to
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.NameValueCollectionPublic Shared Function ParseQueryString (query As String, encoding As Encoding) As NameValueCollectionParameters
- query
- String
The query string to parse.
Returns
A NameValueCollection of query parameters and values.
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.