相关疑难解决方法(0)

在dynamic泛型类上实现动态分派,并且泛型类型参数是另一个类上的私有内部类时,运行时绑定程序会引发异常.

例如:

using System;

public abstract class Dispatcher<T> {
    public T Call(object foo) { return CallDispatch((dynamic)foo); }

    protected abstract T CallDispatch(int foo);
    protected abstract T CallDispatch(string foo);
}

public class Program {
    public static void Main() {
        TypeFinder d = new TypeFinder();

        Console.WriteLine(d.Call(0));
        Console.WriteLine(d.Call(""));
    }

    private class TypeFinder : Dispatcher<CallType> {
        protected override CallType CallDispatch(int foo) {
            return CallType.Int;
        }

        protected override CallType CallDispatch(string foo) {
            return CallType.String;
        }
    }

    private enum CallType { Int, String }
} …

我在Fabio Maulo的博客上看过一篇非常有趣的帖子.如果您不想跳转到网址,这是代码和错误.我定义了一个新的泛型类,如下所示:

public class TableStorageInitializer<TTableEntity> where TTableEntity : class, new()
    {
        public void Initialize()
        {
            InitializeInstance(new TTableEntity());
        }

        public void InitializeInstance(dynamic entity)
        {
            entity.PartitionKey = Guid.NewGuid().ToString();
            entity.RowKey = Guid.NewGuid().ToString();
        }

    }

请注意,InitializeInstance接受一个参数,该参数的类型为dynamic.现在要测试这个类,我定义了另一个嵌套在我的主Program类中的类,如下所示:

class Program
        {
            static void Main(string[] args)
            {
               TableStorageInitializer<MyClass> x = new TableStorageInitializer<MyClass>();
                x.Initialize();
            }
            private class MyClass
            {
                public string PartitionKey { get; set; }
                public string RowKey { get; set; }
                public DateTime Timestamp { get; set; }
            }
        }

注意:内部类"MyClass"被声明为私有.
现在,如果我运行此代码,我会在"entity.PartitionKey = Guide.NewGuid().ToString()"行中获得 …