Question

我正在尝试基于我拥有的C＃解决方案在VB.NET中编写一些东西。在C＃解决方案中，我用以下函数调用该函数：

somefunction(s => Console.WriteLine(s)).Wait();

被调用的方法是：

public static Task somefuntion(Action<string> callback);

在VB.NET中我有

somefunction(Function(s) Console.WriteLine(s)).Wait()

Public Shared somefunction(ByRef callback As Action(Of string)) As Task

任何想法我做错了什么？

Answer 1

使用Sub而不是Function： somefunction(Sub(s) Console.WriteLine(s)).Wait()

Answer 2

一个。在lambda中将Function(s)更改为Sub(s)：

somefunction(Sub(s) Console.WriteLine(s)).Wait()

湾将Function关键字添加到somefunction方法签名：

Public Shared Function somefunction(ByRef callback As Action(Of String)) As Task

Answer 3

检查官方文档

https://msdn.microsoft.com/en-us/library/018hxwa8(v=vs.110).aspx?cs-save-lang=1&cs-lang=vb#code-snippet-1

Module TestAction1
   Public Sub Main
      Dim messageTarget As Action(Of String) 

      If Environment.GetCommandLineArgs().Length > 1 Then
         messageTarget = AddressOf ShowWindowsMessage
      Else
         messageTarget = AddressOf Console.WriteLine
      End If
      messageTarget("Hello, World!")
   End Sub

   Private Sub ShowWindowsMessage(message As String)
      MsgBox(message)
   End Sub   
End Module

VB.NET将函数传递给Action参数

3 个答案: