将返回特定实现T的方法分配给Func变量。

示例代码：

public interface IFoo
{
    void Foo();
}

public class Foo1 : IFoo
{
    public void Foo()
    {
        Console.WriteLine("Foo1 Foo");
    }
}

public class Foo2 : IFoo
{
    public void Foo()
    {
        Console.WriteLine("Foo2 Foo");
    }
}

public static class FooFactory
{
    public static IFoo GetFoo1()
    {
        return new Foo1();
    }

    public static IFoo GetFoo2()
    {
        return new Foo2();
    }
}

public static void Main(string[] args)
{
    Func createFoo = FooFactory.GetFoo1;
    IFoo foo = createFoo();
    foo.Foo(); // 输出 "Foo1 Foo"

    createFoo = FooFactory.GetFoo2;
    foo = createFoo();
    foo.Foo(); // 输出 "Foo2 Foo"
}