AppDomain.AssemblyResolve Evento
Definição
Importante
Algumas informações dizem respeito a um produto pré-lançado que pode ser substancialmente modificado antes de ser lançado. A Microsoft não faz garantias, de forma expressa ou implícita, em relação à informação aqui apresentada.
Ocorre quando a resolução de um conjunto falha.
public:
virtual event ResolveEventHandler ^ AssemblyResolve;
public:
event ResolveEventHandler ^ AssemblyResolve;
public event ResolveEventHandler AssemblyResolve;
[add: System.Security.SecurityCritical]
[remove: System.Security.SecurityCritical]
public event ResolveEventHandler AssemblyResolve;
member this.AssemblyResolve : ResolveEventHandler
[<add: System.Security.SecurityCritical>]
[<remove: System.Security.SecurityCritical>]
member this.AssemblyResolve : ResolveEventHandler
Public Custom Event AssemblyResolve As ResolveEventHandler
Tipo de Evento
Implementações
- Atributos
Exemplos
O exemplo seguinte demonstra o AssemblyResolve evento.
Para que este exemplo de código seja executado, deve fornecer o nome de assembleia totalmente qualificado. Para informações sobre como obter o nome de assembleia totalmente qualificado, consulte Nomes de Assembleia.
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 AssemblyResolveSnippet
{
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;
}
}
type MyType() =
do
printfn "\nMyType instantiated!"
let instantiateMyTypeFail (domain: 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")
|> ignore
with e ->
printfn $"\n{e.Message}"
let instantiateMyTypeSucceed (domain: AppDomain) =
try
let asmname = Assembly.GetCallingAssembly().FullName
domain.CreateInstance(asmname, "MyType")
|> ignore
with e ->
printfn $"\n{e.Message}"
let myResolveEventHandler _ _ =
printfn "Resolving..."
typeof<MyType>.Assembly
let currentDomain = AppDomain.CurrentDomain
// This call will fail to create an instance of MyType since the
// assembly resolver is not set
instantiateMyTypeFail currentDomain
currentDomain.add_AssemblyResolve (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
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
Observações
É responsabilidade ResolveEventHandler deste evento devolver a montagem especificada pela ResolveEventArgs.Name propriedade, ou devolver nula se a montagem não for reconhecida. O assembly deve ser carregado num contexto de execução; Se for carregado no contexto apenas de reflexão, a carga que causou o aumento deste evento falha.
Para orientações sobre a utilização deste evento, veja Resolver Cargas de Montagem.
A partir do .NET Framework 4, a propriedade ResolveEventArgs.RequestingAssembly devolve a montagem que solicitou a carga de montagem que não pôde ser resolvida. Por exemplo, o loader pode não conseguir carregar uma dependência do assembly requerente porque o assembly solicitante e a sua dependência não estão no caminho de sondagem. Saber a identidade do assembly requerente pode ser útil para localizar a dependência ou para identificar a versão correta, se existirem mais do que uma versão da dependência disponível. Para obter mais informações, veja ResolveEventArgs.RequestingAssembly.
Importante
A partir do .NET Framework 4, o evento ResolveEventHandler é gerado para todas as assembleias, incluindo as assembleias de recursos. Em versões anteriores, o evento não era ativado para assemblagens de recursos. Se o sistema operativo for localizado, o handler pode ser chamado várias vezes: uma vez para cada cultura na cadeia de reserva.
Para este evento, a ResolveEventArgs.Name propriedade devolve o nome da assembleia antes de a política ser aplicada.
Importante
Se mais do que um handler de eventos estiver registado para este evento, os handlers de eventos são chamados por ordem até que um handler de eventos devolva um valor que não nullseja . Os gestores de eventos subsequentes são ignorados.
Para obter mais informações sobre como manipular eventos, consulte Manipulando e gerando eventos.