如何使用后期绑定从VB.Net调用位于C#DLL内的方法

Question

我无法控制各种"Init","Accumulate"......方法如何工作,以便从VB.Net代码中调用位于DLL中的方法.

假设要调用的方法具有以下签名:

public double ComputeMeanPosition(ref SortedList<DateTime, double> posByTime)

请您指出使用这些方法的实际示例,或者只是给我一些提示,如何将参数实际传递给方法,调用它并获取结果？

@Olivier Jacot-Descombes:我确实用名称空间名称为类名添加前缀,但却无法访问该对象.事实上,我很惊讶您的善意建议不涉及以下方法,通过内加加载的DLL显示:

Type: MyClassName
        Method: Void Init()
        Method: Void Accumulate(System.Data.SqlTypes.SqlDouble, System.Data.SqlTypes.SqlDateTime, System.Data.SqlTypes.SqlBoolean)
        Method: Void Merge(MyClassName)
        Method: System.Data.SqlTypes.SqlDouble Terminate()
        Method: Void Write(System.IO.BinaryWriter)
        Method: Void Read(System.IO.BinaryReader)
        Method: Boolean Equals(System.Object)
        Method: Int32 GetHashCode()
        Method: System.String ToString()
        Method: System.Type GetType()

编辑

实际上我有一个类似于下面的代码,它成功地设法检查DLL并从中获取了几种类型和方法,给出了我想要调用的方法的上述结果.

这是代码

        For Each oneModule As Reflection.Module In useAssembly.GetLoadedModules()
            Console.WriteLine("   - " & oneModule.Name)
            For Each oneType As System.Type In oneModule.GetTypes()
                Console.WriteLine("     Type: " & oneType.Name)
                For Each oneField As Reflection.FieldInfo In oneType.GetFields()
                    Console.WriteLine("        Field: " & oneField.ToString())
                Next oneField

                For Each oneMethod As Reflection.MethodInfo In oneType.GetMethods()
                    Console.WriteLine("        Method: " & oneMethod.ToString())

                    [[ ADD "Invoke" here ?]]
                Next oneMethod
            Next oneType
        Next oneModule

最后,似乎[[...]]位于应该调用Invoke方法来调用我选择的方法的地方,但这就是我被困住的地方......我是否需要构建调用它之前的一个对象？我应该如何传递参数？如何获得结果？

Answer 1

这样的事情应该有效:

using System;
using System.Reflection;
using System.IO;

public class MainClass
{
      public static int Main(string[] args)
      {
           Assembly a = null;
           try
           {
                a = Assembly.Load("YourLibraryName");
           }
           catch(FileNotFoundException e)
               {Console.WriteLine(e.Message);}

           Type classType = a.GetType("YourLibraryName.ClassName");

           object obj = Activator.CreateInstance(classType);

           object[] paramArray = new object[1];    
           paramArray[0] = new SortledList<DateTime, double>();
           MethodInfo mi = classType.GetMethod("ComputeMeanPosition");
           mi.Invoke(obj, paramArray);

           return 0;
       }
 }

对于VB.NET:

Imports System
Imports System.Reflection
Imports System.IO

Public Class MainClass
    Public Shared Function Main(args As String()) As Integer
        Dim a As Assembly = Nothing
        Try
            a = Assembly.Load("YourLibraryName")
        Catch e As FileNotFoundException
            Console.WriteLine(e.Message)
        End Try

        Dim classType As Type = a.[GetType]("YourLibraryName.ClassName")

        Dim obj As Object = Activator.CreateInstance(classType)

        Dim [paramArray] As Object() = New Object(0) {}
        [paramArray](0) = New SortledList(Of DateTime, Double)()
        Dim mi As MethodInfo = classType.GetMethod("ComputeMeanPosition")
        mi.Invoke(obj, [paramArray])

        Return 0
    End Function
End Class

经测试,这有效:

 Dim a As Assembly = Nothing
    Try
        a = Assembly.Load("TestLib")
    Catch ex As FileNotFoundException
        Console.WriteLine(ex.Message)
    End Try

    Dim classType As Type = a.[GetType]("TestLib.Class1")

    Dim obj As Object = Activator.CreateInstance(classType)

    Dim [paramArray] As Object() = New Object(0) {}
    [paramArray](0) = New SortedList(Of DateTime, Double)()
    Dim mi As MethodInfo = classType.GetMethod("ComputeMeanPosition")
    mi.Invoke(obj, [paramArray])