AppDomain.AssemblyResolve イベント

定義

アセンブリの解決が失敗したときに発生します。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 

実装

属性

AssemblyResolve イベントの例を次に示します。The following sample demonstrates the AssemblyResolve event.

このコード例を実行するには、完全修飾アセンブリ名を指定する必要があります。For this code example to run, you must provide the fully qualified assembly name. 完全修飾アセンブリ名を取得する方法については、「アセンブリ名」を参照してください。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

注釈

このイベントが ResolveEventArgs.Name プロパティによって指定されたアセンブリを返すか、またはアセンブリが認識されない場合は null を返す必要 ResolveEventHandler があります。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. アセンブリは、実行コンテキストに読み込む必要があります。リフレクションのみのコンテキストに読み込まれた場合、このイベントの原因となった読み込みは失敗します。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.

このイベントの使用に関するガイダンスについては、「アセンブリの読み込みの解決」を参照してください。For guidance on the use of this event, see Resolving Assembly Loads.

.NET Framework 4.NET Framework 4以降、ResolveEventArgs.RequestingAssembly プロパティは、解決できなかったアセンブリの読み込みを要求したアセンブリを返します。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. たとえば、要求元のアセンブリとその依存関係がプローブパスにないため、ローダーは要求元のアセンブリの依存関係を読み込むことができない可能性があります。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. 要求元アセンブリの id を知っておくと、依存関係を特定するときや、依存関係のバージョンが複数ある場合に正しいバージョンを特定する際に役立つことがあります。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. 詳細については、「ResolveEventArgs.RequestingAssembly」を参照してください。For more information, see ResolveEventArgs.RequestingAssembly.

重要

.NET Framework 4.NET Framework 4以降では、リソースアセンブリを含むすべてのアセンブリに対して ResolveEventHandler イベントが発生します。Beginning with the .NET Framework 4.NET Framework 4, the ResolveEventHandler event is raised for all assemblies, including resource assemblies. 以前のバージョンでは、リソースアセンブリに対してイベントが発生していませんでした。In earlier versions, the event was not raised for resource assemblies. オペレーティングシステムがローカライズされている場合は、ハンドラーが複数回呼び出される可能性があります。フォールバックチェーンのカルチャごとに1回です。If the operating system is localized, the handler might be called multiple times: once for each culture in the fallback chain.

このイベントの場合、ResolveEventArgs.Name プロパティは、ポリシーが適用される前にアセンブリ名を返します。For this event, the ResolveEventArgs.Name property returns the assembly name before policy is applied.

重要

このイベントに複数のイベントハンドラーが登録されている場合は、イベントハンドラーが nullない値を返すまで、イベントハンドラーが順番に呼び出されます。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. 後続のイベントハンドラーは無視されます。Subsequent event handlers are ignored.

イベントの処理の詳細については、「処理とイベントの発生」を参照してください。For more information about handling events, see Handling and Raising Events.

セキュリティ

SecurityCriticalAttribute
直前の呼び出し元に完全信頼が必要です。Requires full trust for the immediate caller. このメンバーは、部分的に信頼されているコードまたは透過的なコードでは使用できません。This member cannot be used by partially trusted or transparent code.

適用対象

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