将20个过载的子文件合并为一个文件

Question

我正在与一个第三方库进行连接，这个第三方库连接到一个旧的数据库系统。有一种方法 - CallProg，称为“存储过程”（缺乏更好的翻译 - 人群中的任何Pick用户？）。然而，而不是做这样的事情：

Public Sub CallProg(ProgName, ParamArray ProgArgs() As String) 
    ... 
End Sub 

，甚至这样的：

Public Sub CallProg(ProgName, Optional Arg1 As String, Optional Arg2 As String ... Optional Arg20 As String) 

他们这样做：

Public Sub CallProg(ProgName) 
Public Sub CallProg(ProgName, Arg1 As String) 
Public Sub CallProg(ProgName, Arg1 As String, Arg2 As String) 
Public Sub CallProg(ProgName, Arg1 As String, Arg2 As String, Arg3 As String) 
... 
Public Sub CallProg(ProgName, Arg1 As String, ... Arg20 As String) 

我正在写一个抽象类来处理登录，设置环境等等，所以它可以在许多其他项目中用作通用的“帮手”类。有什么办法可以包装CallProg的sub，不涉及20个重载？

Answer 1

这是一个非常快速的想法，如何使用反射做到这一点。我不知道，如果它的最好的方式，但它应该工作...

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 

    CallProg("ProgName", {"testArg1", "TestArg2"}) 

End Sub 

Private Sub CallProg(ByVal ProgName As String, ByVal Params As IEnumerable(Of String)) 

    Dim testClass As New Test1 

    Dim methodTypes As List(Of Type) = 
     Params.Select(Function(x) GetType(String)).ToList 

    methodTypes.Add(GetType(String)) 

    Dim methodToBeCalled As Reflection.MethodInfo = 
     testClass.GetType.GetMethod("CallProg", 
            System.Reflection.BindingFlags.Instance Or System.Reflection.BindingFlags.Public, 
            Type.DefaultBinder, 
            methodTypes.ToArray, 
            Nothing) 


    Dim paramsToPass As New List(Of String) 

    paramsToPass.Add(ProgName) 
    paramsToPass.AddRange(Params) 

    methodToBeCalled.Invoke(testClass, paramsToPass.ToArray) 

End Sub 

末级

公共类的Test1

Public Sub CallProg(ByVal ProgName As String) 
    Debug.WriteLine("Sub0 called") 
End Sub 

Public Sub CallProg(ByVal ProgName As String, ByVal Arg1 As String) 
    Debug.WriteLine("Sub1 called") 
End Sub 

Public Sub CallProg(ByVal ProgName As String, ByVal Arg1 As String, ByVal Arg2 As String) 
    Debug.WriteLine("Sub2 called") 
End Sub 

Public Sub CallProg(ByVal ProgName As String, ByVal Arg1 As String, ByVal Arg2 As String, ByVal Arg3 As String) 
    Debug.WriteLine("Sub3 called") 
End Sub 

末级

Answer 2

另一种方式按照Rene147的建议：

Private _act As New APIClass 

Public Sub CallProg(ByVal ProgName As String, ByVal ParamArray ProgArgs() As String) 
    Try 
     Dim tList As New List(Of Type) 
     tList.Add(GetType(String)) 

     Dim aList As New List(Of String) 
     aList.Add(ProgName) 

     For Each arg In ProgArgs 
      tList.Add(GetType(String).MakeByRefType) 
      'tList.Add(GetType(String)) <-- only use this if all the args are ByVal 
      aList.Add(arg) 
     Next 
     Dim typeList As Type() = tList.ToArray 
     Dim argList As String() = aList.ToArray 

     GetType(APIClass).GetMethod("CallProg", typeList).Invoke(_act, argList) 
    Catch ex As Exception 
     Console.Write("Error running program {0}.", ProgName) 
    End Try 
End Sub