Question

当我还没有声明实例时，我可以创建一个指向实例函数的指针吗？现在我正在使用反射来调用我的方法，但似乎这可以通过各种代表更容易。我只是想不出来。我将调用的方法将始终返回相同的类型，并且没有参数。

以下是一些示例代码，用于说明我正在尝试做的事情：

Private Shared Function A() As Object

    Return Lauch(????) ' should call FunctionA of the instance (undeclared here)

End Function


Private Shared Function B() As Object

    Return Lauch(????) ' should call FunctionB of the instance (undeclared here)

End Function


Private Shared Function Lauch(Of T)(ByVal instanceFunc As Func(Of T)) As Object

    ' long and repetitive operations that I don't want to repeat in function A and B

    Dim myInstance As New MyClass()

    Return myInstance.instanceFunc()

End Function

现在我正在做类似以下的事情并且它有效，但我觉得应该有更好的方法：

Private Shared Function A() As Object

    Return Lauch("FunctionA")

End Function


Private Shared Function B() As Object

    Return Lauch("FunctionB")

End Function


Private Shared Function Lauch(ByVal instanceFunc As String) As Object

    ' long and repetitive operations that I don't want to repeat in function A and B

    Dim myInstance As New MyClass()

    Return myInstance.GetType().GetMethod(instanceFunc).Invoke(myInstance, Nothing))

End Function

Answer 1

这个怎么样？

Private Shared Function A() As Object
    Return Lauch(Function(x) x.A())
End Function


Private Shared Function Lauch(ByVal instanceFunc As Func(Of CustomClass, Object)) As Object
    ' long and repetitive operations
    Dim myInstance As New CustomClass()
    Return instanceFunc(myInstance)
End Function

基本上，您定义了确定Lauch函数结果的函数。这是一个需要CustomClass并返回Object的函数。在A方法中，您定义此函数以返回实例的A函数的结果。

.Net实例函数指针

1 个答案: