您不能。您只能定义一个类时覆盖的方法。

You can't. You can only override a method when defining a class.

***的办法是转而使用适当的 Func键委托作为一个占位符，并允许呼叫者提供实现这种方式：

The best option is instead to use an appropriate Func delegate as a placeholder and allow the caller to supply the implementation that way:

public class SomeClass
{
    public Func<string> Method { get; set; }

    public void PrintSomething()
    {
        if(Method != null) Console.WriteLine(Method());
    }
}

// Elsewhere in your application

var instance = new SomeClass();
instance.Method = () => "Hello World!";
instance.PrintSomething(); // Prints "Hello World!"