多动作赋值加法运行同步吗？

Question

使用 += 运算符时，操作是运行同步还是异步？

Action actions = () => Console.WriteLine("First Action");

actions += () => Console.WriteLine("Second Action");
actions += () => Console.WriteLine("Third Action");
actions += () => Console.WriteLine("Fourth Action");

actions();

此代码块打印：

First Action
Second Action
Third Action
Fourth Action

Answer 1

此操作将运行同步，只需执行此操作：

Action actions = () => Console.WriteLine("First Action");

actions += () => Console.WriteLine("Second Action");
actions += () => {
                    Thread.Sleep(2000);
                    Console.WriteLine("Third Action")
                 };
actions += () => Console.WriteLine("Fourth Action");
actions();

并且你可以检查一个线程等待写最后一个

Answer 2

您的问题的答案很简短：操作运行同步。就像事件句柄一样，动作按照分配/订阅的顺序顺序执行。

您可能已经注意到，该块已按顺序打印了所有字符串。如果你这样定义：

Action actions = () => Console.WriteLine("2");
actions += () => Console.WriteLine("3");
actions += () => Console.WriteLine("1");
actions += () => Console.WriteLine("4");

无论发生什么，您总是会看到 2 3 1 4 被打印出来。

多动作赋值加法运行同步吗？

Does multiple action assignment addition run synchronously?

c#

synchronization

action

asynchronous

async-await