VB.Net: Call a module Method or Routine dynamically with parameters - vb.net

Question

I want to run a Method using a variable name that is stored in a Module with a parameter:
Dim subName as String = "sub1"
Dim param as Integer = 123
sub1(param) <- I want to run this using the **subName** string
I don't want to use Select Case because the Methods are in many different modules and I don't want to maintain a select-case function.
I looked up CallByName but it seems this only works for Classes. I can't figure out how to set the object ObjectRef when it comes to Modules :
Public Function CallByName(ByVal ObjectRef As System.Object,ByVal ProcName As String,ByVal UseCallType As CallType, ByVal Args() As Object) As Object
Is there a way to do this in VB.Net?
Edit: To make it really simple, I need the equivalent of VBA's:
Application.Run module_name.sub_name param

Answer 1

You can use reflection to create a delegate to the methods in the Module. I would load the created delegates into a Dictionary(Of String, Action(Of Int32)).
Action(Of Int32) is chosen because it matches the signature you specified of a subroutine taking an integer parameter.
Assume you have a Module defined like this:
Module SomeModule
Public Sub Sub1(arg As Int32)
Console.WriteLine("Sub1: {0}", arg)
End Sub
Public Sub Sub2(arg As Int32)
Console.WriteLine("Sub2: {0}", arg)
End Sub
End Module
Now to create and store the delegates in a dictionary.
Private methods As New Dictionary(Of String, Action(Of Int32))
Sub LoadMethods()
Dim modType As Type = GetType(SomeModule)
Dim mi As Reflection.MethodInfo
mi = modType.GetMethod("Sub1", BindingFlags.Static Or BindingFlags.Public)
methods.Add(mi.Name, CType(mi.CreateDelegate(GetType(Action(Of Int32))), Action(Of Int32)))
mi = modType.GetMethod("Sub2", BindingFlags.Static Or BindingFlags.Public)
methods.Add(mi.Name, CType(mi.CreateDelegate(GetType(Action(Of Int32))), Action(Of Int32)))
End Sub
You can retrieve and invoke the delegate like this:
methods("Sub1")(123)
methods("Sub2")(456)
Edit: I sometimes makes things to complicated. The LoadMethods method can be done without reflection like this:
Sub LoadMethods()
methods.Add("Sub1", New Action(Of Int32)(AddressOf SomeModule.Sub1))
methods.Add("Sub2", New Action(Of Int32)(AddressOf SomeModule.Sub1))
End Sub
Edit 2: Based on edit to question and comment below.
Edit: To make it really simple, I need the equivalent of VBA's:
Application.Run module_name.sub_name param
You will need to first extract the Module type from its containing assembly based on the entered name. Then you can retrieve the MethodInfo as shown above. The following example assumes that the module is contained in the executing assembly and has minimal checks implemented. It will require you to provide the module name, method name and an array properly typed method arguments. In a real world scenario, it would probably need to take a string of the arguments and perform some type of dynamic type casting to build up the typedArgs array based on calling MethodInfo.GetParameters.
Private Shared Sub Exec(moduleName As String, methodName As String, typedArgs As Object())
Dim asm As Reflection.Assembly = Assembly.GetExecutingAssembly
Dim modType As Type = asm.GetType(String.Format("{0}.{1}", asm.GetName.Name, moduleName))
If modType IsNot Nothing Then
Dim mi As Reflection.MethodInfo
mi = modType.GetMethod(methodName, BindingFlags.Static Or BindingFlags.Public)
If mi IsNot Nothing Then
mi.Invoke(Nothing, typedArgs)
End If
End If
End Sub
Example usage: Exec("SomeModule", "Sub1", New Object() {123})

Answer 2

Lets say you want to call subroutine (or function) sub1 with parameter 123 with optionally given module name module1
Call example, If module name is not available (function name to invoke should be unique among project):
Dim FunctionName As String = "sub1"
Dim Param As Integer = 123
InvokeModuleFunction(FunctionNameToCall:=FunctionName, FunctionParameters:=Param)
Alternatively, If you know module name:
Dim FunctionName As String = "sub1"
Dim Param As Integer = 123
Dim ModuleName As String = "module1"
InvokeModuleFunction(FunctionNameToCall:=FileType, ModuleName:=ModuleName, FunctionParameters:=Param)
InvokeModuleFunction definition
Private Sub InvokeModuleFunction(FunctionNameToCall As String, FunctionParameters As Object, Optional ModuleName As String = Nothing)
Dim MyReflectionAssembly = Reflection.Assembly.GetExecutingAssembly()
Dim MyFunctionType As Type
If IsNothing(ModuleName) Then
'Gets function without ModuleName. FunctionName should be unique in the assembly/programm.
MyFunctionType = MyReflectionAssembly.DefinedTypes.Where(Function(x) x.DeclaredMethods.Where(Function(y) y.Name = FunctionNameToCall).Count > 0).FirstOrDefault
Else
'Gets function using ModuleName, if available
MyFunctionType = MyReflectionAssembly.DefinedTypes.Where(Function(x) x.Name = ModuleName AndAlso x.DeclaredMethods.Where(Function(y) y.Name = FunctionNameToCall).Count > 0).FirstOrDefault
End If
If Not IsNothing(MyFunctionType) Then MyFunctionType.GetMethod(FunctionNameToCall).Invoke(MyFunctionType, New Object() {FunctionParameters})
End Sub
Alternatively you can use more than one parameter in invoking.
You would need to modify the above function to allow to pass more than one parameter.
The invoke part would look like:
FunctionType.GetMethod(FunctionNameToCall).Invoke(FunctionType, New Object() {Par1, Par2, Par3})