c#中多播委托的执行顺序
发布时间：2020-12-16 02:02:19 所属栏目：百科 来源：网络整理
导读：我看了 If you are using multicast delegates,you should be aware that the order in which methods chained to the same delegate will be called is formally undefined. You should,therefore,avoid writing code that relies on such methods being ca
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我看了
但是当我尝试使用这段代码时 using System;
namespace Wrox.ProCSharp.Delegates
{
class Program
{
static void One()
{
Console.WriteLine("watch when i occur");
throw new Exception("Error in watching");
}
static void Two()
{
Console.WriteLine("count");
}
static void Three()
{
Console.WriteLine("great");
}
static void Main()
{
Action d1 = Two;
d1+=Two;
d1+=Two;
d1+=Two;
d1+=One;
d1+=Three;
d1+=Three;
d1+=Three;
Delegate[] delegates = d1.GetInvocationList();
foreach (Action d in delegates)
try
{
d1();
}
catch(Exception)
{
Console.WriteLine("Exception Caught");
}
}
}
}
这是我得到的输出 count count count count watch when i occur Exception Caught count count count count watch when i occur Exception Caught count count count count watch when i occur Exception Caught count count count count watch when i occur Exception Caught count count count count watch when i occur Exception Caught count count count count watch when i occur Exception Caught count count count count watch when i occur Exception Caught count count count count watch when i occur Exception Caught 显然,委托是按照我编写的非常指定的顺序执行的,并且没有一个Three()方法在抛出异常的One()方法之前执行. 所以我缺少一些东西或者委托中的实际方法按指定的顺序执行,我从书中读到的东西意味着什么. 解决方法
undefined – 行为被指定为任意的(就像你忘记妻子的生日后会发生什么……)所以取决于任意行为是有潜在危险的.
可能是5年后,微软发布了.NET 7,你的程序结果发生了变化.这是“未定义”的意思,今天没有多少测量值可以让您对下一个版本,甚至您的计算机和Fred的计算机之间感到舒适.所以观察它只是有趣的,但对可靠性没有用.依靠你观察到的东西在技术上是错误的. 有时,供应商会特别记录未定义的内容,以便在实施过程中保持灵活性. （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |