Programming Microsoft Visual Basic .NET/Programming Microsoft Visual Basic .NET (Microsoft Press)(X08-78517)(2002).bin/14 assemblies/appdomaindemo/module1.vb

Text File | 2002-03-20 | 6.5 KB | 175 lines

Option Strict Off

Module Module1

    ' Set this to True to generate the ShowAppDomainData.exe assembly
    ' (but requires manual renaming of the exe file)
#Const GEN_SHOWAPPDOMAINDATAEXE = False

    Sub Main()

#If GEN_SHOWAPPDOMAINDATAEXE Then
        ' If inside the ShowAppDomainData.Exe program, show
        ' AppDomain properties and exit.
        TestAppDomainProperties
        Exit Sub
#End If

        'TestAppDomainProperties()
        'TestCreateDomain()
        TestCreateInstance()
        'TestProcessExit()
        'TestUnhandledException()

        ' These statements are usuful when running inside Visual Studio.NET
        Console.WriteLine("")
        Console.WriteLine(">>> Press Enter to terminate the program <<<")
        Console.ReadLine()
    End Sub

    ' this procedure displays AppDomain properties

    Sub TestAppDomainProperties()
        ' Get a reference to the running AppDomain.
        Dim ad As AppDomain = AppDomain.CurrentDomain

        ' Print main properties.
        Console.WriteLine("----- AppDomain Data ------------------")
        Console.WriteLine("BaseDirectory = {0}", ad.BaseDirectory)
        Console.WriteLine("FriendlyName = {0}", ad.FriendlyName)
        Console.WriteLine("RelativeSearchPath = {0}", ad.RelativeSearchPath)
        Console.WriteLine("ShadowCopyFiles = {0}", ad.ShadowCopyFiles)
        Console.WriteLine("CurrentThreadId = {0}", AppDomain.GetCurrentThreadId)

        ' Display additional information from the AppDomainSetup object.
        Dim ads As AppDomainSetup = ad.SetupInformation

        Console.WriteLine("ApplicationName = {0}", ads.ApplicationName)
        Console.WriteLine("CachePath = {0}", ads.CachePath)
        Console.WriteLine("ConfigurationFile = {0}", ads.ConfigurationFile)
        Console.WriteLine("DisallowPublisherPolicy = {0}", ads.DisallowPublisherPolicy)
        Console.WriteLine("LoaderOptimization = {0}", ads.LoaderOptimization)
        Console.WriteLine("PrivateBinPath = {0}", ads.PrivateBinPath)
        Console.WriteLine("ShadowCopyFiles = {0}", ads.ShadowCopyFiles)

        ' Display the list of loaded files
        Dim asm As Reflection.Assembly
        Console.WriteLine("Assemblies loaded in current domain")
        For Each asm In ad.GetAssemblies
            Console.WriteLine("  " & asm.FullName)
        Next
        Console.WriteLine("----- End of AppDomain Data ------------")
    End Sub

    ' this procedure tests AppDomain creation

    ' IMPORTANT: this routine assumes that you have an EXE named
    ' ShowAppDomainData.exe in the BIN directory. If you don't, you
    ' can copy the file found in the project's main directory.

    ' This executable file can be created by setting the
    ' GEN_SHOWAPPDOMAINDATAEXE constant to True, compiling the
    ' source and then renaming the EXE to ShowAppDomainData.exe

    Sub TestCreateDomain()
        ' Prepare setup info
        Dim ads As New AppDomainSetup()
        ads.ApplicationName = "NewApplication"
        ads.ApplicationBase = "c:\windows\temp"
        ads.PrivateBinPath = "bins;assemblies"
        ' Create the new AppDomain
        Dim ad As AppDomain = AppDomain.CreateDomain("NewAppDomain", Nothing, ads)

        ' Run an assembly inside the appdomain
        ad.ExecuteAssembly("ShowAppDomainData.exe")

        ' Unload the AppDomain
        AppDomain.Unload(ad)
    End Sub

    ' this procedure tests the CreateInstanceFrom method

    ' IMPORTANT: it relies on the presence of the TestAssembly.Dll
    ' file in the BIN subdirectory. If this file isn't there, you can copy
    ' it from the main project's directory, or you can recompile the
    ' TestAssembly project

    Sub TestCreateInstance()
        ' Create the new AppDomain
        Dim ad As AppDomain = AppDomain.CreateDomain("NewAppDomain")
        ' Load
        Dim oh As System.Runtime.Remoting.ObjectHandle
        Dim o As Object

        oh = ad.CreateInstanceFrom("TestAppDomain.Dll", "TestAppDomain.AppDomainData")
        o = oh.Unwrap
        Console.WriteLine("ThreadID = {0}    (current={1})", o.ThreadID, AppDomain.GetCurrentThreadId)
        Console.WriteLine("AppName = {0}", o.AppName)
        Console.WriteLine("ExeName= {0}", o.ExeName)

        oh = ad.CreateInstanceFrom("TestAppDomain.Dll", "TestAppDomain.AppDomainData2")
        o = oh.Unwrap
        Console.WriteLine("ThreadID = {0}    (current={1})", o.ThreadID, AppDomain.GetCurrentThreadId)
        Console.WriteLine("AppName = {0}", o.AppName)
        Console.WriteLine("ExeName= {0}", o.ExeName)
    End Sub

    ' this procedure tests the ProcessExit event

    Dim WithEvents CurrAppDomain As AppDomain
    Public AppIsExiting As Boolean

    Sub TestProcessExit()
        ' Prepare to trap AppDomain events.
        CurrAppDomain = AppDomain.CurrentDomain
        ' Create a DataClass instance that will be collected right now
        Dim dc As New DataClass()
        dc = Nothing
        GC.Collect()
        ' Create an instance of DataClass that will be collected when the application exits.
        Dim dc2 As New DataClass()
    End Sub

    Public Sub CurrAppDomain_ProcessExit(ByVal sender As Object, ByVal e As System.EventArgs) Handles CurrAppDomain.ProcessExit
        Console.WriteLine("Exiting...")
        AppIsExiting = True
    End Sub

    ' this procedure tests unhandled exceptions on secondary
    ' and main threads, and the UnhandledException event

    Sub TestUnhandledException()
        ' Prepare to trap AppDomain events.
        CurrAppDomain = AppDomain.CurrentDomain

        ' Cause an exception on a secondary thread
        Dim t As New Threading.Thread(AddressOf ThrowException)
        t.Start()
        Threading.Thread.Sleep(500)

        ' Cause a fatal exception on the main thread
        Throw New IndexOutOfRangeException()

    End Sub

    Sub ThrowException()
        Throw New DivideByZeroException()
    End Sub

    Sub CurrAppDomain_UnhandledException(ByVal sender As Object, ByVal e As System.UnhandledExceptionEventArgs) Handles CurrAppDomain.UnhandledException
        ' get a reference to the exception
        Dim ex As Exception = DirectCast(e.ExceptionObject, Exception)
        ' Show information on the current exception.
        Console.WriteLine("{0}  (IsTerminating={1})", ex.Message, e.IsTerminating)
    End Sub
End Module

Class DataClass
    Public ID As Integer

    Protected Overrides Sub Finalize()
        Console.WriteLine("Finalizing DataClass (AppIsExiting is {0})", AppIsExiting)
    End Sub
End Class