Dns.BeginGetHostEntry Méthode

Définition

Résout un nom d'hôte ou une adresse IP en instance de IPHostEntry de manière asynchrone.

Surcharges

BeginGetHostEntry(IPAddress, AsyncCallback, Object)

Résout une adresse IP en instance de IPHostEntry de manière asynchrone.

BeginGetHostEntry(String, AsyncCallback, Object)

Résout un nom d'hôte ou une adresse IP en instance de IPHostEntry de manière asynchrone.

BeginGetHostEntry(IPAddress, AsyncCallback, Object)

Résout une adresse IP en instance de IPHostEntry de manière asynchrone.

public:
 static IAsyncResult ^ BeginGetHostEntry(System::Net::IPAddress ^ address, AsyncCallback ^ requestCallback, System::Object ^ stateObject);
public static IAsyncResult BeginGetHostEntry (System.Net.IPAddress address, AsyncCallback? requestCallback, object? stateObject);
public static IAsyncResult BeginGetHostEntry (System.Net.IPAddress address, AsyncCallback requestCallback, object stateObject);
static member BeginGetHostEntry : System.Net.IPAddress * AsyncCallback * obj -> IAsyncResult
Public Shared Function BeginGetHostEntry (address As IPAddress, requestCallback As AsyncCallback, stateObject As Object) As IAsyncResult

Paramètres

address
IPAddress

Adresse IP à résoudre.

requestCallback
AsyncCallback

Délégué AsyncCallback qui fait référence à la méthode à appeler quand l'opération est terminée.

stateObject
Object

Objet défini par l'utilisateur qui comporte des informations sur l'opération. Cet objet est passé au délégué requestCallback quand l'opération est terminée.

Retours

IAsyncResult

Instance de IAsyncResult qui fait référence à la demande asynchrone.

Exceptions

address a la valeur null.

Une erreur s'est produite lors de la résolution de address.

address est une adresse IP non valide.

Exemples

L’exemple de code suivant utilise la BeginGetHostEntry méthode pour résoudre une adresse IP sur une IPHostEntry instance.

    // Signals when the resolve has finished.
public:
    static ManualResetEvent^ GetHostEntryFinished =
        gcnew ManualResetEvent(false);

    // define the state object for the callback. 
    // use hostName to correlate calls with the proper result.
    ref class ResolveState
    {
    public:
        String^ hostName;
        IPHostEntry^ resolvedIPs;

        ResolveState(String^ host)
        {
            hostName = host;
        }

        property IPHostEntry^ IPs 
        {
            IPHostEntry^ get()
            {
                return resolvedIPs;
            }

            void set(IPHostEntry^ IPs)
            {
                resolvedIPs = IPs;
            }
        }

        property String^ host 
        {
            String^ get()
            {
                return hostName;
            }

            void set(String^ host)
            {
                hostName = host;
            }
        }
    };

    // Record the IPs in the state object for later use.
    static void GetHostEntryCallback(IAsyncResult^ ar)
    {
        ResolveState^ ioContext = (ResolveState^)(ar->AsyncState);

        ioContext->IPs = Dns::EndGetHostEntry(ar);
        GetHostEntryFinished->Set();
    }


    // Determine the Internet Protocol(IP) addresses for this 
    // host asynchronously.
public:
    static void DoGetHostEntryAsync(String^ hostName)
    {
        GetHostEntryFinished->Reset();
        ResolveState^ ioContext = gcnew ResolveState(hostName);

        Dns::BeginGetHostEntry(ioContext->host,
            gcnew AsyncCallback(GetHostEntryCallback), ioContext);
        // Wait here until the resolve completes 
        // (the callback calls .Set())
        GetHostEntryFinished->WaitOne();

        Console::WriteLine("EndGetHostEntry({0}) returns:", ioContext->host);
      
        for (int i = 0; i < ioContext->IPs->AddressList->Length; i++)
        {
            Console::WriteLine("    {0}", ioContext->IPs->AddressList[i]->ToString());
        }

//      for each (IPAddress^ address in ioContext->IPs)
//      {
//          Console::WriteLine("{0} ", address);
//      }
    }
// Signals when the resolve has finished.
public static ManualResetEvent GetHostEntryFinished =
    new ManualResetEvent(false);

// Define the state object for the callback.
// Use hostName to correlate calls with the proper result.
public class ResolveState
{
    string hostName;
    IPHostEntry resolvedIPs;

    public ResolveState(string host)
    {
        hostName = host;
    }

    public IPHostEntry IPs
    {
        get { return resolvedIPs; }
        set { resolvedIPs = value; }
    }

    public string host
    {
        get { return hostName; }
        set { hostName = value; }
    }
}

// Record the IPs in the state object for later use.
public static void GetHostEntryCallback(IAsyncResult ar)
{
    ResolveState ioContext = (ResolveState)ar.AsyncState;
    ioContext.IPs = Dns.EndGetHostEntry(ar);
    GetHostEntryFinished.Set();
}

// Determine the Internet Protocol (IP) addresses for
// this host asynchronously.
public static void DoGetHostEntryAsync(string hostname)
{
    GetHostEntryFinished.Reset();
    ResolveState ioContext= new ResolveState(hostname);

    Dns.BeginGetHostEntry(ioContext.host,
        new AsyncCallback(GetHostEntryCallback), ioContext);

    // Wait here until the resolve completes (the callback
    // calls .Set())
    GetHostEntryFinished.WaitOne();

    Console.WriteLine("EndGetHostEntry({0}) returns:", ioContext.host);

    foreach (IPAddress address in ioContext.IPs.AddressList)
    {
        Console.WriteLine($"    {address}");
    }
}
' Signals when the resolve has finished.
Dim Shared GetHostEntryFinished As ManualResetEvent = New ManualResetEvent(False)

' Define the state object for the callback. 
' Use hostName to correlate calls with the proper result.
Class ResolveState
    
    Dim hostName As String
    Dim resolvedIPs As IPHostEntry

    Public Sub New(host As String)
        hostName = host
    End Sub

    Public Property IPs AS IPHostEntry
        Get
            Return resolvedIPs
        End Get
        Set
            resolvedIPs = value
        End Set
    End Property

    Public Property host As String
        Get
            Return hostName
        End Get
        Set
            hostName = value
        End Set
    End Property

End Class

' Record the IPs in the state object for later use.
Shared Sub GetHostEntryCallback(ar As IAsyncResult)

    Dim ioContext As ResolveState = ar.AsyncState

    ioContext.IPs = Dns.EndGetHostEntry(ar)
    GetHostEntryFinished.Set()

End Sub

' Determine the Internet Protocol (IP) addresses for 
' this host asynchronously.
Shared Sub DoGetHostEntryAsync(hostname As String)
    
    GetHostEntryFinished.Reset()
    Dim ioContext As ResolveState = New ResolveState(hostname)

    Dns.BeginGetHostEntry(ioContext.host,AddressOf GetHostEntryCallback, ioContext)

    ' Wait here until the resolve completes (the callback 
    ' calls .Set())
    GetHostEntryFinished.WaitOne()

    Console.WriteLine($"EndGetHostEntry({ioContext.host}) returns:")

    Dim addresses As IPAddress() = ioContext.IPs.AddressList

    Dim index As Integer
    For index = 0 To addresses.Length - 1
        Console.WriteLine($"    {addresses(index)}")
    Next index

End Sub

Remarques

La BeginGetHostEntry méthode interroge de façon asynchrone un serveur DNS pour les adresses IP et les alias associés à une adresse IP.

Note Ce membre émet des informations de suivi lorsque vous activez le suivi réseau dans votre application. Pour plus d’informations, consultez Le suivi réseau dans le .NET Framework.

L’opération asynchrone BeginGetHostEntry doit être terminée en appelant la EndGetHostEntry méthode. En règle générale, la méthode est appelée par le requestCallback délégué.

Cette méthode ne bloque pas tant que l’opération n’est pas terminée. Pour bloquer jusqu’à ce que l’opération soit terminée, utilisez la GetHostEntry méthode.

Pour plus d’informations sur l’utilisation du modèle de programmation asynchrone, consultez Appeler des méthodes synchrones de façon asynchrone

S’applique à

BeginGetHostEntry(String, AsyncCallback, Object)

Résout un nom d'hôte ou une adresse IP en instance de IPHostEntry de manière asynchrone.

public:
 static IAsyncResult ^ BeginGetHostEntry(System::String ^ hostNameOrAddress, AsyncCallback ^ requestCallback, System::Object ^ stateObject);
public static IAsyncResult BeginGetHostEntry (string hostNameOrAddress, AsyncCallback? requestCallback, object? stateObject);
public static IAsyncResult BeginGetHostEntry (string hostNameOrAddress, AsyncCallback requestCallback, object stateObject);
static member BeginGetHostEntry : string * AsyncCallback * obj -> IAsyncResult
Public Shared Function BeginGetHostEntry (hostNameOrAddress As String, requestCallback As AsyncCallback, stateObject As Object) As IAsyncResult

Paramètres

hostNameOrAddress
String

Nom de l'hôte ou adresse IP à résoudre.

requestCallback
AsyncCallback

Délégué AsyncCallback qui fait référence à la méthode à appeler quand l'opération est terminée.

stateObject
Object

Objet défini par l'utilisateur qui comporte des informations sur l'opération. Cet objet est passé au délégué requestCallback quand l'opération est terminée.

Retours

IAsyncResult

Instance de IAsyncResult qui fait référence à la demande asynchrone.

Exceptions

hostNameOrAddress a la valeur null.

La longueur de hostNameOrAddress est supérieure à 255 caractères.

Une erreur s'est produite lors de la résolution de hostNameOrAddress.

hostNameOrAddress est une adresse IP non valide.

Exemples

L’exemple de code suivant utilise la BeginGetHostEntry méthode pour résoudre une adresse IP sur une IPHostEntry instance.

    // Signals when the resolve has finished.
public:
    static ManualResetEvent^ GetHostEntryFinished =
        gcnew ManualResetEvent(false);

    // define the state object for the callback. 
    // use hostName to correlate calls with the proper result.
    ref class ResolveState
    {
    public:
        String^ hostName;
        IPHostEntry^ resolvedIPs;

        ResolveState(String^ host)
        {
            hostName = host;
        }

        property IPHostEntry^ IPs 
        {
            IPHostEntry^ get()
            {
                return resolvedIPs;
            }

            void set(IPHostEntry^ IPs)
            {
                resolvedIPs = IPs;
            }
        }

        property String^ host 
        {
            String^ get()
            {
                return hostName;
            }

            void set(String^ host)
            {
                hostName = host;
            }
        }
    };

    // Record the IPs in the state object for later use.
    static void GetHostEntryCallback(IAsyncResult^ ar)
    {
        ResolveState^ ioContext = (ResolveState^)(ar->AsyncState);

        ioContext->IPs = Dns::EndGetHostEntry(ar);
        GetHostEntryFinished->Set();
    }


    // Determine the Internet Protocol(IP) addresses for this 
    // host asynchronously.
public:
    static void DoGetHostEntryAsync(String^ hostName)
    {
        GetHostEntryFinished->Reset();
        ResolveState^ ioContext = gcnew ResolveState(hostName);

        Dns::BeginGetHostEntry(ioContext->host,
            gcnew AsyncCallback(GetHostEntryCallback), ioContext);
        // Wait here until the resolve completes 
        // (the callback calls .Set())
        GetHostEntryFinished->WaitOne();

        Console::WriteLine("EndGetHostEntry({0}) returns:", ioContext->host);
      
        for (int i = 0; i < ioContext->IPs->AddressList->Length; i++)
        {
            Console::WriteLine("    {0}", ioContext->IPs->AddressList[i]->ToString());
        }

//      for each (IPAddress^ address in ioContext->IPs)
//      {
//          Console::WriteLine("{0} ", address);
//      }
    }
// Signals when the resolve has finished.
public static ManualResetEvent GetHostEntryFinished =
    new ManualResetEvent(false);

// Define the state object for the callback.
// Use hostName to correlate calls with the proper result.
public class ResolveState
{
    string hostName;
    IPHostEntry resolvedIPs;

    public ResolveState(string host)
    {
        hostName = host;
    }

    public IPHostEntry IPs
    {
        get { return resolvedIPs; }
        set { resolvedIPs = value; }
    }

    public string host
    {
        get { return hostName; }
        set { hostName = value; }
    }
}

// Record the IPs in the state object for later use.
public static void GetHostEntryCallback(IAsyncResult ar)
{
    ResolveState ioContext = (ResolveState)ar.AsyncState;
    ioContext.IPs = Dns.EndGetHostEntry(ar);
    GetHostEntryFinished.Set();
}

// Determine the Internet Protocol (IP) addresses for
// this host asynchronously.
public static void DoGetHostEntryAsync(string hostname)
{
    GetHostEntryFinished.Reset();
    ResolveState ioContext= new ResolveState(hostname);

    Dns.BeginGetHostEntry(ioContext.host,
        new AsyncCallback(GetHostEntryCallback), ioContext);

    // Wait here until the resolve completes (the callback
    // calls .Set())
    GetHostEntryFinished.WaitOne();

    Console.WriteLine("EndGetHostEntry({0}) returns:", ioContext.host);

    foreach (IPAddress address in ioContext.IPs.AddressList)
    {
        Console.WriteLine($"    {address}");
    }
}
' Signals when the resolve has finished.
Dim Shared GetHostEntryFinished As ManualResetEvent = New ManualResetEvent(False)

' Define the state object for the callback. 
' Use hostName to correlate calls with the proper result.
Class ResolveState
    
    Dim hostName As String
    Dim resolvedIPs As IPHostEntry

    Public Sub New(host As String)
        hostName = host
    End Sub

    Public Property IPs AS IPHostEntry
        Get
            Return resolvedIPs
        End Get
        Set
            resolvedIPs = value
        End Set
    End Property

    Public Property host As String
        Get
            Return hostName
        End Get
        Set
            hostName = value
        End Set
    End Property

End Class

' Record the IPs in the state object for later use.
Shared Sub GetHostEntryCallback(ar As IAsyncResult)

    Dim ioContext As ResolveState = ar.AsyncState

    ioContext.IPs = Dns.EndGetHostEntry(ar)
    GetHostEntryFinished.Set()

End Sub

' Determine the Internet Protocol (IP) addresses for 
' this host asynchronously.
Shared Sub DoGetHostEntryAsync(hostname As String)
    
    GetHostEntryFinished.Reset()
    Dim ioContext As ResolveState = New ResolveState(hostname)

    Dns.BeginGetHostEntry(ioContext.host,AddressOf GetHostEntryCallback, ioContext)

    ' Wait here until the resolve completes (the callback 
    ' calls .Set())
    GetHostEntryFinished.WaitOne()

    Console.WriteLine($"EndGetHostEntry({ioContext.host}) returns:")

    Dim addresses As IPAddress() = ioContext.IPs.AddressList

    Dim index As Integer
    For index = 0 To addresses.Length - 1
        Console.WriteLine($"    {addresses(index)}")
    Next index

End Sub

Remarques

La BeginGetHostEntry méthode interroge un serveur DNS pour l’adresse IP associée à un nom d’hôte ou une adresse IP.

Note Ce membre émet des informations de suivi lorsque vous activez le suivi réseau dans votre application. Pour plus d’informations, consultez Le suivi réseau dans le .NET Framework.

L’opération asynchrone BeginGetHostEntry doit être terminée en appelant la EndGetHostEntry méthode. En règle générale, la méthode est appelée par le requestCallback délégué.

Cette méthode ne bloque pas tant que l’opération n’est pas terminée. Pour bloquer jusqu’à ce que l’opération soit terminée, utilisez la GetHostEntry méthode.

Pour plus d’informations sur l’utilisation du modèle de programmation asynchrone, consultez Appeler des méthodes synchrones de façon asynchrone.

S’applique à