WebClient.QueryString-Eigenschaft

Ruft eine Auflistung der Name-Wert-Paare für Abfragen auf, die der Anforderung zugeordnet sind, oder legt diese fest.

Namespace: System.Net
Assembly: System (in system.dll)

Syntax

'Declaration
Public Property QueryString As NameValueCollection
'Usage
Dim instance As WebClient
Dim value As NameValueCollection

value = instance.QueryString

instance.QueryString = value

public NameValueCollection QueryString { get; set; }

public:
property NameValueCollection^ QueryString {
    NameValueCollection^ get ();
    void set (NameValueCollection^ value);
}

/** @property */
public NameValueCollection get_QueryString ()

/** @property */
public void set_QueryString (NameValueCollection value)

public function get QueryString () : NameValueCollection

public function set QueryString (value : NameValueCollection)

Eigenschaftenwert

Eine NameValueCollection mit den der Anforderung zugeordneten Name-Wert-Paaren für Abfragen. Wenn der Anforderung keine Paare zugeordnet sind, ist der Wert eine leere NameValueCollection.

Hinweise

Die QueryString-Eigenschaft enthält eine NameValueCollection-Instanz mit den Name-Wert-Paaren, die dem URI als Abfragezeichenfolge angefügt sind. Der Inhalt der QueryString-Eigenschaft folgt einem Fragezeichen (?), und Name-Wert-Paare sind durch ein kaufmännisches Und-Zeichen (&) voneinander getrennt.

Beispiel

Im folgenden Codebeispiel werden Benutzereingaben aus der Befehlszeile zum Erstellen einer NameValueCollection verwendet, die der QueryString-Eigenschaft zugeordnet ist. Anschließend wird die Antwort vom Server in eine lokale Datei gedownloadet.

Dim uriString As String = "https://www.contoso.com/search"
' Create a new WebClient instance.
Dim myWebClient As New WebClient()
' Create a new NameValueCollection instance to hold the QueryString parameters and values.
Dim myQueryStringCollection As New NameValueCollection()
Console.Write(("Enter the word(s), separated by space characters, to search for in " + uriString + ": "))
' Read user input phrase to search in uriString.
Dim searchPhrase As String = Console.ReadLine()
If searchPhrase.Length > 1 Then
    'Assign the user-defined search phrase.
    myQueryStringCollection.Add("q", searchPhrase)
' If error, default to search 'Microsoft'.
Else
    myQueryStringCollection.Add("q", "Microsoft")
End If 
' Assign auxilliary parameters required for the search.
Console.WriteLine(("Searching " + uriString + " ......."))
' Attach QueryString to the WebClient.
myWebClient.QueryString = myQueryStringCollection
' Download the search results Web page into 'searchresult.htm' for inspection.
myWebClient.DownloadFile(uriString, "searchresult.htm")
Console.WriteLine((ControlChars.Cr + "Download of " + uriString + " was successful. Please see 'searchresult.htm' for results."))

string uriString = "https://www.contoso.com/search";
// Create a new WebClient instance.
WebClient myWebClient = new WebClient();
// Create a new NameValueCollection instance to hold the QueryString parameters and values.
NameValueCollection myQueryStringCollection = new NameValueCollection();
Console.Write("Enter the word(s), separated by space character to search for in " +  uriString + ": ");
// Read user input phrase to search for at uriString.
string searchPhrase = Console.ReadLine();
if (searchPhrase.Length > 1)
    // Assign the user-defined search phrase.
    myQueryStringCollection.Add("q",searchPhrase);
else
    // If error, default to search for 'Microsoft'.
    myQueryStringCollection.Add("q","Microsoft");        
// Assign auxilliary parameters required for the search.
Console.WriteLine("Searching " + uriString + " .......");
// Attach QueryString to the WebClient.
myWebClient.QueryString = myQueryStringCollection;
// Download the search results Web page into 'searchresult.htm' for inspection.
myWebClient.DownloadFile (uriString, "searchresult.htm");
Console.WriteLine("\nDownload of " + uriString + " was successful. Please see 'searchresult.htm' for results.");

String^ uriString = "https://www.contoso.com/search";
// Create a new WebClient instance.
WebClient^ myWebClient = gcnew WebClient;
// Create a new NameValueCollection instance to hold the QueryString parameters and values.
NameValueCollection^ myQueryStringCollection = gcnew NameValueCollection;
Console::Write( "Enter the word(s), separated by space character to search for in {0}: ", uriString );
// Read user input phrase to search for at uriString.
String^ searchPhrase = Console::ReadLine();
if ( searchPhrase->Length > 1 )
{
   // Assign the user-defined search phrase.
   myQueryStringCollection->Add( "q", searchPhrase );
}
else
{
   // If error, default to search for 'Microsoft'.
   myQueryStringCollection->Add( "q", "Microsoft" );
}
// Assign auxilliary parameters required for the search.
Console::WriteLine( "Searching {0} .......", uriString );
// Attach QueryString to the WebClient.
myWebClient->QueryString = myQueryStringCollection;
// Download the search results Web page into 'searchresult.htm' for inspection.
myWebClient->DownloadFile( uriString, "searchresult.htm" );
Console::WriteLine( "\nDownload of {0} was successful. Please see 'searchresult.htm' for results.", uriString );

String uriString = "https://www.contoso.com/search";
// Create a new WebClient instance.
WebClient myWebClient = new WebClient();
// Create a new NameValueCollection instance to hold the
// QueryString parameters and values.
NameValueCollection myQueryStringCollection = new 
    NameValueCollection();
Console.Write("Enter the word(s), separated by space character" 
    + " to search for in " + uriString + ": ");
// Read user input phrase to search for at uriString.
String searchPhrase = Console.ReadLine();
if (searchPhrase.get_Length() > 1) {
    // Assign the user-defined search phrase.
    myQueryStringCollection.Add("q", searchPhrase);
}
else {
    // If error, default to search for 'Microsoft'.
    myQueryStringCollection.Add("q", "Microsoft");
} 
// Assign auxilliary parameters required for the search.
Console.WriteLine("Searching " + uriString + " .......");
// Attach QueryString to the WebClient.
myWebClient.set_QueryString(myQueryStringCollection);
// Download the search results Web page into 'searchresult.htm'
// for inspection.
myWebClient.DownloadFile(uriString, "searchresult.htm");
Console.WriteLine("\nDownload of " + uriString + " was successful." 
    + " Please see 'searchresult.htm' for results.");

Plattformen

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

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

WebClient-Klasse
WebClient-Member
System.Net-Namespace