Question

这是我的代码

Module Module1
    Private Delegate Sub word(ByVal A As String, ByVal B As String, C As String)
    Dim A, B, C As String
    Sub Main()
        Console.WriteLine("type something")
        A = Console.ReadLine()
        Console.WriteLine("type something else")
        B = Console.ReadLine()
        Console.WriteLine("type something else")
        C = Console.ReadLine()
        Dim objword As New word(AddressOf first)
        objword(A, B, C)
        first(A, B, C)
        objword = New word(AddressOf Second)
        objword(A, B, C)
        Second(A, B, C)
        objword = New word(AddressOf third)
        objword(A, B, C)
        third(A, B, C)
    End Sub
    Sub first(ByVal A As String, ByVal B As String, C As String)
        Console.WriteLine(A)
    End Sub
    Sub Second(ByVal A As String, ByVal B As String, C As String)
        Console.WriteLine(B)
    End Sub
    Sub third(ByVal A As String, ByVal B As String, C As String)
        Console.WriteLine(C)
        Console.ReadKey()
    End Sub

End Module

当我运行它时，它会打印两次A和B字符串，但只打印一次C字符串。如果我按Enter键，它会第二次打印C sting。我知道console.readkey正在这样做。

我的问题是：
为什么字符串打印两次？
为什么console.readkey会阻止最后一次打印呢？如何只打印一次字符串？

编辑：通过将console.readkey移动到sub main的末尾，所有字符串都打印两次

Answer 1

因为你这称呼：

 objword(A, B, C)
 first(A, B, C)

objword指向first方法。您也可以为其他方法重复此操作。问题是你为什么这样做？

执行此操作：

first(A,B,C)

代表不需要简单地执行方法。

字符串打印除了上次以外多次？

1 个答案: