c# - 如何将委托(delegate)从 c# 转换为 vb.net？

Question

我有这段代码，我正在尝试将其从 C# 转换为 VB.net:

public object Invoke(object instance, object[] inputs, out object[] outputs)
        {
            // Create a new, STA thread
            object[] staOutputs = null;
            object retval = null;
            Thread thread = new Thread(
                delegate(){
                    retval = _innerInvoker.Invoke(instance, inputs, out staOutputs);
                });
            thread.SetApartmentState(ApartmentState.STA);
            thread.Start();
            thread.Join();
            outputs = staOutputs;
            return retval;
        }

整个委托(delegate)的事情让我失望。谁能帮我转换这个？或者是否有一篇文章解释了如何做？

Answer 1

这是一个匿名函数，VB.Net 不支持这样的匿名函数(假设是 .Net 2.0，因为在 .Net 3.5 中，它会被写成 lambda 表达式)。

您在 VB.Net 中可以做的最好的事情是将匿名函数(委托(delegate))作为单独的方法添加到同一类中，并使用 AddressOf 运算符来引用这个新方法。

---

更新:
再次阅读您的代码，翻译很复杂，因为您的匿名方法将被解释为闭包，这意味着 C# 编译器在将代码转换为 IL 之前会对代码进行复杂的转换；创建一个全新的类是为了捕获(关闭)方法中引用的局部变量:

Class InnerInvokerClosure
    Public instance As Object
    Public inputs() As Object
    Public staOutputs() As Object
    Public retValue As Object

    Public _innerInvoker As SomeDelegateType

    Sub New(ByRef instance as Object, ByRef inputs() as Object, ByRef staOutputs() As Object, ByRef retValue As Object, ByRef _innerInvoker As SomeDelegateType)
        Me.instance = instance
        Me.inputs = inputs
        Me.staOoutputs = staOutputs
        Me.retValue = retValue

        Me._innerInvoker = _innerInvoker
    End Sub

    Public Function Invoke() As Object
        retValue = _innerInvoker.Invoke(instance, inputs, staOutputs);
    End Function

End Class

Public Function Invoke(ByVal instance As Object, ByVal inputs() as Object, ByRef outputs() As Object) As Object
    Dim closure As New InnerInvokerClosure(instance, inputs, Nothing, Nothing, _innerInvoker)

    Dim t As New Thread(AddressOf closure.Invoke)
    t.SetApartmentState(ApartmentState.STA)
    t.Start()
    t.Join()

    outputs = closure.staOutputs
    return closure.retValue      
End Function

请注意，此翻译未经测试且可能是错误的:确切的转换可能非常复杂。