AppDomain.AssemblyResolve Event
Updated: May 2010
Occurs when the resolution of an assembly fails.
Assembly: mscorlib (in mscorlib.dll)
'Declaration Public Event AssemblyResolve As ResolveEventHandler 'Usage Dim instance As AppDomain Dim handler As ResolveEventHandler AddHandler instance.AssemblyResolve, handler
Implements
_AppDomain.AssemblyResolveFor this event, the ResolveEventArgs.Name property returns the assembly name before policy is applied.
It is the responsibility of ResolveEventHandler for this event to return the assembly that resolves the type, assembly, or resource. 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.
To register an event handler for this event, you must have the required permissions, or a SecurityException is thrown.
For more information about handling events, see Consuming Events.
The following example demonstrates the AssemblyResolve event.
For this code example to run, you must provide the fully qualified assembly name. For information about how to obtain the fully qualified assembly name, see Assembly Names.
Public Class MyType Public Sub New() Console.WriteLine() Console.WriteLine("MyType instantiated!") End Sub 'New End Class 'MyType 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 'Main 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 'InstantiateMyType 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 'Test
- SecurityPermission
to add an event handler for this event. Associated enumeration: SecurityPermissionFlag.ControlAppDomain. Security action: LinkDemand.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.