C# list中ConvertAll的使用

 static double TakeSquareRoot(int x)
 {
     //return Math.Sqrt(x);
     return x + ;
 }

 static void Main(string[] args)
 {
     List<int> integers = new List<int>();
     integers.Add();
     integers.Add();
     integers.Add();
     integers.Add();

     Converter<int, double> converter = TakeSquareRoot;
     List<double> doubles;
     doubles = integers.ConvertAll<double>(converter);
     foreach (double d in doubles)
     {
         Console.WriteLine(d);
     }

     Console.WriteLine("OK");

     Console.ReadKey();
 }