System.Reflection and InvokeMember, storing type, assembly, and object in a class

Posted by Cyclone on Stack Overflow See other posts from Stack Overflow or by Cyclone
Published on 2010-03-08T00:33:39Z Indexed on 2010/03/08 0:52 UTC
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I have tested code to call a method inside of a compiled DLL, and it works. I created a class to store the object, type, and loaded assembly, but something is lost in translation because it is unable to find the member I wish to invoke.

If I create a type, object, and assembly, and properly load everything into these and perform InvokeMember on the type, it works just fine. However, when I use the things inside of my class, it throws a MissingMemberException and does not invoke the member, obviously.

What am I doing wrong? The member in question is a subroutine which takes one argument, a string.

This is quite frustrating.

Code being called:

    Dim MyLoadedAssembly As New LoadedAssembly()
    MyLoadedAssembly.MyAssembly = Assembly.LoadFrom("display.dll")
    MyLoadedAssembly.MyObject = MyLoadedAssembly.MyAssembly.CreateInstance("Display.UI.Window")
    MyLoadedAssembly.MyType = MyLoadedAssembly.MyAssembly.GetType("Display.UI.Window")
    Dim args() As Object = {"test"}
    MyLoadedAssembly.InvokeMember("Show", args)

    Private Class LoadedAssembly
        Public MyType As Type
        Public MyObject As Object
        Public MyAssembly As Assembly
        Public Function InvokeMember(ByVal name As String, ByVal args() As Object)
            Return MyType.InvokeMember(name, BindingFlags.Default Or BindingFlags.InvokeMethod Or BindingFlags.GetProperty Or BindingFlags.Instance, Nothing, MyObject, args)
        End Function
    End Class

Code inside of display.dll:

Namespace UI
    Public Class Window
        Private wind As New System.Windows.Forms.Form
        Public FullScreen As Boolean = False
        Public Overloads Sub Show(ByVal text As String)
            wind.Show()
            wind.Text = text
        End Sub
        Public Overloads Sub Show()
            wind.Show()
        End Sub
    End Class
End Namespace

The root namespace for display.dll is Display.

Why is my code only working when not within this class?

System.MissingMethodException was unhandled
  Message="Method 'Display.UI.Window.Show' not found."
  Source="mscorlib"
  StackTrace:
       at System.RuntimeType.InvokeMember(String name, BindingFlags bindingFlags, Binder binder, Object target, Object[] providedArgs, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParams)
       at System.Type.InvokeMember(String name, BindingFlags invokeAttr, Binder binder, Object target, Object[] args)
       at IDE.IDE.LoadedAssembly.InvokeMember(String name, Object[] args) in C:\Documents and Settings\Davey\Desktop\RaptorScript\RaptorScript\RaptorScript\IDE.vb:line 69
       at IDE.IDE.IDE_Load(Object sender, EventArgs e) in C:\Documents and Settings\Davey\Desktop\RaptorScript\RaptorScript\RaptorScript\IDE.vb:line 50
       at System.EventHandler.Invoke(Object sender, EventArgs e)
       at System.Windows.Forms.Form.OnLoad(EventArgs e)
       at System.Windows.Forms.Form.OnCreateControl()
       at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
       at System.Windows.Forms.Control.CreateControl()
       at System.Windows.Forms.Control.WmShowWindow(Message& m)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
       at System.Windows.Forms.ContainerControl.WndProc(Message& m)
       at System.Windows.Forms.Form.WmShowWindow(Message& m)
       at System.Windows.Forms.Form.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.SafeNativeMethods.ShowWindow(HandleRef hWnd, Int32 nCmdShow)
       at System.Windows.Forms.Control.SetVisibleCore(Boolean value)
       at System.Windows.Forms.Form.SetVisibleCore(Boolean value)
       at System.Windows.Forms.Control.set_Visible(Boolean value)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(ApplicationContext context)
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
       at IDE.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

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