在dotnet中使用泛型來處理任意數量參數的函數？

Question

我想有一個函數可以「包裝」任何其他函數調用。在這種特殊情況下，它將允許我圍繞某些特定操作編寫一些更通用的事務處理。

我可以寫這對於任何特定數量的參數，例如對於一個參數：

Public Shared Sub WrapFunc(Of T)(ByVal f As Action(Of T), ByVal arg As T) 
    ' Test some stuff, start transaction 
    f(arg) 
    ' Test some stuff, end transaction 
End Sub 

...但我希望能有這樣的處理任何數量的參數，而無需有重複碼0指定參數時，1對阿根廷，2個ARGS等

有一個這樣做的方式？

[編輯]感謝羅伯特·弗雷澤的C＃代碼。作爲參考，這裏有一個翻譯到VB：

[EDIT2]更正後的代碼。不幸的是，在vb中似乎沒有獨立的「ActAsFunc」函數。從好的一面來看，那些使用封閉裝置的人是隱藏的，封閉裝置可以重複使用。

Public Shared Sub WrapFunc(ByVal f As Action) 
    _WrapFunc(f) 
End Sub 
Public Shared Sub WrapFunc(Of T1)(ByVal f As Action(Of T1), ByVal arg1 As T1) 
    _WrapFunc(Closure(f, arg1)) 
End Sub 
Public Shared Sub WrapFunc(Of T1, T2)(ByVal f As Action(Of T1, T2), ByVal arg1 As T1, ByVal arg2 As T2) 
    _WrapFunc(Closure(f, arg1, arg2)) 
End Sub 

Private Shared Sub _WrapFunc(ByVal f As Action) 
    ' Test some stuff, start transaction 
    f() 
    ' Test some stuff, end transaction 
End Sub 

Private Shared Function Closure(Of T1)(ByVal f As Action(Of T1), ByVal arg1 As T1) As Action 
    Return New Action(Function() _ActAsFunc(f, arg1)) 
End Function 
Private Shared Function Closure(Of T1, T2)(ByVal f As Action(Of T1, T2), ByVal arg1 As T1, ByVal arg2 As T2) As Action 
    Return New Action(Function() _ActAsFunc(f, arg1, arg2)) 
End Function 

Private Shared Function _ActAsFunc(Of T1)(ByVal f As Action(Of T1), ByVal arg1 As T1) As Object 
    f(arg1) : Return Nothing 
End Function 
Private Shared Function _ActAsFunc(Of T1, T2)(ByVal f As Action(Of T1, T2), ByVal arg1 As T1, ByVal arg2 As T2) As Object 
    f(arg1, arg2) : Return Nothing 
End Function 

Answer 1

沒有。我也希望有，我一直這樣做。

內部，MS使用文本模板/代碼生成工具來生成重複代碼。 C＃中的選項是在參數周圍創建閉包，然後將它們作爲無參數System.Action傳遞給另一個函數;我不確定VB.NET是否支持這一點。

這是我在C＃中做的;希望有人用VB.NET經驗可以翻譯這個：

public void add(Action action, EventFlags flags) { addInternal(action, flags); } 
public void add<T1>(Action<T1> action, T1 p1, EventFlags flags) { addInternal(closure(action, p1), flags); } 
public void add<T1, T2>(Action<T1, T2> action, T1 p1, T2 p2, EventFlags flags) { addInternal(closure(action, p1, p2), flags); } 
public void add<T1, T2, T3>(Action<T1, T2, T3> action, T1 p1, T2 p2, T3 p3, EventFlags flags) { addInternal(closure(action, p1, p2, p3), flags); } 
public void add<T1, T2, T3, T4>(Action<T1, T2, T3, T4> action, T1 p1, T2 p2, T3 p3, T4 p4, EventFlags flags) { addInternal(closure(action, p1, p2, p3, p4), flags); } 

private static Action closure<T1>(Action<T1> action, T1 p1) { return() => action(p1); } 
private static Action closure<T1, T2>(Action<T1, T2> action, T1 p1, T2 p2) { return() => action(p1, p2); } 
private static Action closure<T1, T2, T3>(Action<T1, T2, T3> action, T1 p1, T2 p2, T3 p3) { return() => action(p1, p2, p3); } 
private static Action closure<T1, T2, T3, T4>(Action<T1, T2, T3, T4> action, T1 p1, T2 p2, T3 p3, T4 p4) { return() => action(p1, p2, p3, p4); } 

Answer 2

我還沒有泛型試過，但對於一個ParamArray？

Public Shared Sub WrapFunc(Of T)(ByVal f As Action(Of T()), ByVal ParamArray args() As T) 
    ' Test some stuff, start transaction 
    f(args) 
    ' Test some stuff, end transaction 
End Sub 

Answer 3

你不能使用ParamArray？

Public Shared Sub WrapFunc(Of T)(ByVal f As Action(Of T), ByVal ParamArray args() As T) 
     ' Test some stuff, start transaction 
     For Each arg As T In args 
      f(arg) 
     Next 

     ' Test some stuff, end transaction 
    End Sub