Func和委托零碎代码

冷不防 2022-08-03 16:41 107阅读 0赞

很久之前转载的，[http://blog.csdn.net/Joyhen/article/details/9699739][http_blog.csdn.net_Joyhen_article_details_9699739]

今天一个函授式写法的多层嵌套Func搞的头晕，索性回忆下。零碎的代码如下：

public delegate int MyDelegate(int a, int b);
    
    public static int function(int a, int b) { return a + b; }
    
    static void Main(string[] args) {
        MyDelegate delfun = new MyDelegate(function);
        MyDelegate delkk = delegate(int a, int b) { return a + b; }; //a,b参数不能推断
        MyDelegate lambdakk = (a, b) = >a + b;                       //a,b参数可以根据MyDelegate来推断
        Func < int,int,int > funkk = (a, b) = >a + b;                //a,b参数可以根据Func的参数来推断
        int result = delfun.Invoke(1, 2); //delfun(1, 2);
        Console.WriteLine(result);
        Console.WriteLine(lambdakk(1, 2));
        Console.WriteLine(lambdakk(1, 2));
        Console.WriteLine(funkk(1, 2));
    
        Func < double,double > myfunc = (x) = >2.0 * x * x - 0.5 * x;
        Console.WriteLine(myfunc(1)); //1.5
        //or
        Console.WriteLine((myfunc = (x) = >2.0 * x * x - 0.5 * x)(1)); //1.5
        //阶层函数
        Func<Func< int,int >,Func< int,int >> F = factorial = >n = >n == 0 ? 1 : n * factorial(n - 1);
    
        //一个参数的括号可以省略
        //Func<int, Func<int>> fa = (x) => () => x * 3;
        Func < int,Func < int >> fa = x = >() = >x * 3;
        //Func<int, Func<int, int>> fb = (x) => (y) => x * y;
        Func < int,Func < int,int >> fb = x = >y = >x * y;
        Console.WriteLine("fa:{0}, fb:{1}", fa(10)(), fb(10)(5)); //30,50
    
        Console.ReadKey();
    }

Func<object, string> fn = x => PrintTaskObjectState(x);
      //Task<string> taskWithInActualMethodAndState = new Task<string>(new Func<object, string>(PrintTaskObjectState),
      //Task<string> taskWithInActualMethodAndState = new Task<string>(fn, "This is the Task state, could be any object");
      Task<string> taskWithInActualMethodAndState = new Task<string>(x => PrintTaskObjectState(x), "This is the Task state, could be any object");

private static string PrintTaskObjectState(object state)
    {
         Console.WriteLine(state.ToString());
         return "***WOWSERS***";
    }

[http_blog.csdn.net_Joyhen_article_details_9699739]: http://blog.csdn.net/Joyhen/article/details/9699739