回顾委托的几种调用方法

 

   class Program
    {

        static int[] arr = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

        static void Main(string[] args)
        {
            var result1= arr.Where ( new Func<int,bool>(Filter));//用Func委托和Filter方法

            var result2 = arr.Where(delegate(int value)
               { return value % 2 == 0; });//用匿名委托

            var result3 = arr.Where(value => value % 2 == 0);//用lambda表达式

            var result4 = arr.Where(value =>Filter(value));//用lambda表达式+具名方法

            var result5 = arr.Where(value => {
                return Filter(value);
            });//lambda表达式+匿名方法

        }

        static bool Filter(int value)
        {
            return value % 2 == 0;
        }


        static void Write(IEnumerable<int> arr)
        {
            foreach (var ele in arr)
                Console.WriteLine(ele);
        }
    }

 

 

Module Module1

    Dim arr As Integer() = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}

    Sub Main()
        Dim result1 = arr.Where(New Func(Of Integer, Boolean)(AddressOf Filter))


        Dim result11 = arr.Where(AddressOf Filter) 'VB会自生成一个与Func签名相同的委托


        Dim result2 = arr.Where(New Func(Of Integer, Boolean)(Function(value)
                                                                  Return value Mod 2 = 0
                                                              End Function))

        Dim result3 = arr.Where(
            Function(value As Integer)
                Return value Mod 2 = 0
            End Function)
    End Sub

    Function Filter(ByVal value As Integer) As Boolean
        Return value Mod 2 = 0
    End Function
End Module

 

 

两个语言各有优势，缺憾也很明显