AppDomain.AssemblyResolve AppDomain.AssemblyResolve AppDomain.AssemblyResolve AppDomain.AssemblyResolve Event

Definizione

Si verifica quando la risoluzione di un assembly ha esito negativo.Occurs when the resolution of an assembly fails.

public:
 virtual event ResolveEventHandler ^ AssemblyResolve;
[add: System.Security.SecurityCritical]
[remove: System.Security.SecurityCritical]
public event ResolveEventHandler AssemblyResolve;
member this.AssemblyResolve : ResolveEventHandler 
Public Custom Event AssemblyResolve As ResolveEventHandler 

Implementazioni

Attributi

Esempi

Nell'esempio seguente viene illustrato AssemblyResolve l'evento.The following sample demonstrates the AssemblyResolve event.

Per eseguire questo esempio di codice, è necessario specificare il nome completo dell'assembly.For this code example to run, you must provide the fully qualified assembly name. Per informazioni su come ottenere il nome completo dell'assembly, vedere nomi degli assembly.For information about how to obtain the fully qualified assembly name, see Assembly Names.

public ref class MyType
{
public:
    MyType()
    {
        Console::WriteLine();
        Console::WriteLine("MyType instantiated!");
    }
};

class Test
{
public:
    static void Main()
    {
        AppDomain^ currentDomain = AppDomain::CurrentDomain;

        // This call will fail to create an instance of MyType since the
        // assembly resolver is not set
        InstantiateMyTypeFail(currentDomain);

        currentDomain->AssemblyResolve += gcnew ResolveEventHandler(&Test::MyResolveEventHandler);

        // This call will succeed in creating an instance of MyType since the
        // assembly resolver is now set.
        InstantiateMyTypeFail(currentDomain);

        // This call will succeed in creating an instance of MyType since the
        // assembly name is valid.
        InstantiateMyTypeSucceed(currentDomain);
    }

private:
    static void InstantiateMyTypeFail(AppDomain^ domain)
    {
        // Calling InstantiateMyType will always fail since the assembly info
        // given to CreateInstance is invalid.
        try
        {
            // You must supply a valid fully qualified assembly name here.
            domain->CreateInstance("Assembly text name, Version, Culture, PublicKeyToken", "MyType");
        }
        catch (Exception^ e)
        {
            Console::WriteLine();
            Console::WriteLine(e->Message);
        }
    }

    static void InstantiateMyTypeSucceed(AppDomain^ domain)
    {
        try
        {
            String^ asmname = Assembly::GetCallingAssembly()->FullName;
            domain->CreateInstance(asmname, "MyType");
        }
        catch (Exception^ e)
        {
            Console::WriteLine();
            Console::WriteLine(e->Message);
        }
    }

    static Assembly^ MyResolveEventHandler(Object^ sender, ResolveEventArgs^ args)
    {
        Console::WriteLine("Resolving...");
        return MyType::typeid->Assembly;
    }
};

int main()
{
    Test::Main();
}
public class MyType
{
    public MyType()
    {
        Console.WriteLine();
        Console.WriteLine("MyType instantiated!");
    }
}

class Test
{
    public static void Main()
    {
        AppDomain currentDomain = AppDomain.CurrentDomain;

        // This call will fail to create an instance of MyType since the
        // assembly resolver is not set
        InstantiateMyTypeFail(currentDomain);

        currentDomain.AssemblyResolve += new ResolveEventHandler(MyResolveEventHandler);

        // This call will succeed in creating an instance of MyType since the
        // assembly resolver is now set.
        InstantiateMyTypeFail(currentDomain);

        // This call will succeed in creating an instance of MyType since the
        // assembly name is valid.
        InstantiateMyTypeSucceed(currentDomain);
    }

    private static void InstantiateMyTypeFail(AppDomain domain)
    {
        // Calling InstantiateMyType will always fail since the assembly info
        // given to CreateInstance is invalid.
        try
        {
            // You must supply a valid fully qualified assembly name here.
            domain.CreateInstance("Assembly text name, Version, Culture, PublicKeyToken", "MyType");
        }
        catch (Exception e)
        {
            Console.WriteLine();
            Console.WriteLine(e.Message);
        }
    }

    private static void InstantiateMyTypeSucceed(AppDomain domain)
    {
        try
        {
            string asmname = Assembly.GetCallingAssembly().FullName;
            domain.CreateInstance(asmname, "MyType");
        }
        catch (Exception e)
        {
            Console.WriteLine();
            Console.WriteLine(e.Message);
        }
    }

    private static Assembly MyResolveEventHandler(object sender, ResolveEventArgs args)
    {
        Console.WriteLine("Resolving...");
        return typeof(MyType).Assembly;
    }
}
Public Class MyType

    Public Sub New()
        Console.WriteLine()
        Console.WriteLine("MyType instantiated!")
    End Sub

End Class

Class Test

    Public Shared Sub Main()
        Dim currentDomain As AppDomain = AppDomain.CurrentDomain

        ' This call will fail to create an instance of MyType since the
        ' assembly resolver is not set
        InstantiateMyTypeFail(currentDomain)

        AddHandler currentDomain.AssemblyResolve, AddressOf MyResolveEventHandler

        ' This call will succeed in creating an instance of MyType since the
        ' assembly resolver is now set.
        InstantiateMyTypeFail(currentDomain)

        ' This call will succeed in creating an instance of MyType since the
        ' assembly name is valid.
        InstantiateMyTypeSucceed(currentDomain)
    End Sub

    Private Shared Sub InstantiateMyTypeFail(domain As AppDomain)
        ' Calling InstantiateMyType will always fail since the assembly info
        ' given to CreateInstance is invalid.
        Try
            ' You must supply a valid fully qualified assembly name here.
            domain.CreateInstance("Assembly text name, Version, Culture, PublicKeyToken", "MyType")
        Catch e As Exception
            Console.WriteLine()
            Console.WriteLine(e.Message)
        End Try
    End Sub

    Private Shared Sub InstantiateMyTypeSucceed(domain As AppDomain)
        Try
            Dim asmname As String = Assembly.GetCallingAssembly().FullName
            domain.CreateInstance(asmname, "MyType")
        Catch e As Exception
            Console.WriteLine()
            Console.WriteLine(e.Message)
        End Try
    End Sub

    Private Shared Function MyResolveEventHandler(sender As Object, args As ResolveEventArgs) As Assembly
        Console.WriteLine("Resolving...")
        Return GetType(MyType).Assembly
    End Function 'MyResolveEventHandler

End Class

Commenti

È responsabilità dell' ResolveEventHandler oggetto per questo evento restituire l'assembly specificato ResolveEventArgs.Name dalla proprietà o per restituire null se l'assembly non è riconosciuto.It is the responsibility of the ResolveEventHandler for this event to return the assembly that is specified by the ResolveEventArgs.Name property, or to return null if the assembly is not recognized. L'assembly deve essere caricato in un contesto di esecuzione. Se viene caricato nel contesto di sola reflection, il carico che ha causato la generazione di questo evento ha esito negativo.The assembly must be loaded into an execution context; if it is loaded into the reflection-only context, the load that caused this event to be raised fails.

Per istruzioni sull'uso di questo evento, vedere risoluzione dei caricamenti di assembly.For guidance on the use of this event, see Resolving Assembly Loads.

A partire da .NET Framework 4.NET Framework 4, la ResolveEventArgs.RequestingAssembly proprietà restituisce l'assembly che ha richiesto il caricamento dell'assembly che non è stato possibile risolvere.Beginning with the .NET Framework 4.NET Framework 4, the ResolveEventArgs.RequestingAssembly property returns the assembly that requested the assembly load that could not be resolved. Ad esempio, il caricatore potrebbe non essere in grado di caricare una dipendenza dell'assembly richiedente perché l'assembly richiedente e la relativa dipendenza non sono nel percorso di probe.For example, the loader might be unable to load a dependency of the requesting assembly because the requesting assembly and its dependency are not in the probing path. Conoscere l'identità dell'assembly richiedente può essere utile per individuare la dipendenza o per identificare la versione corretta, se è disponibile più di una versione della dipendenza.Knowing the identity of the requesting assembly might be useful in locating the dependency or in identifying the correct version, if more than one version of the dependency is available. Per ulteriori informazioni, vedere ResolveEventArgs.RequestingAssembly.For more information, see ResolveEventArgs.RequestingAssembly.

Importante

A partire da .NET Framework 4.NET Framework 4, l' ResolveEventHandler evento viene generato per tutti gli assembly, inclusi gli assembly di risorse.Beginning with the .NET Framework 4.NET Framework 4, the ResolveEventHandler event is raised for all assemblies, including resource assemblies. Nelle versioni precedenti l'evento non è stato generato per gli assembly di risorse.In earlier versions, the event was not raised for resource assemblies. Se il sistema operativo è localizzato, il gestore potrebbe essere chiamato più volte: una volta per ogni lingua nella catena di fallback.If the operating system is localized, the handler might be called multiple times: once for each culture in the fallback chain.

Per questo evento, la ResolveEventArgs.Name proprietà restituisce il nome dell'assembly prima che venga applicato il criterio.For this event, the ResolveEventArgs.Name property returns the assembly name before policy is applied.

Importante

Se per questo evento è registrato più di un gestore eventi, i gestori eventi vengono chiamati in ordine fino a quando un gestore eventi non nullrestituisce un valore diverso da.If more than one event handler is registered for this event, the event handlers are called in order until an event handler returns a value that isn't null. I gestori eventi successivi vengono ignorati.Subsequent event handlers are ignored.

Per ulteriori informazioni sulla gestione degli eventi, consultare gestione e generazione di eventi.For more information about handling events, see Handling and Raising Events.

Sicurezza

SecurityCriticalAttribute
richiede l'attendibilità totale per il chiamante immediato.Requires full trust for the immediate caller. Questo membro non può essere utilizzato da codice parzialmente attendibile o trasparente.This member cannot be used by partially trusted or transparent code.

Si applica a

Vedi anche