正则匹配超时处理

Posted 2021-02-06 cuihongyu3503319

使用正则匹配比较大的数据时就会发生程序超时并没有异常弹出，而且电脑cpu会到达100%

在.Net4.5中微软有改进的方法，直接调用很方便，但.Net4.5以下就没有，下面写下自己找的处理方法

1、.Net4.5中：　　

Regex reg = new Regex(正则, RegexOptions.IgnoreCase, TimeSpan.FromSeconds(2));

TimeSpan.FromSeconds就是设置的超时时间，如超过就返回为空，FromSeconds=2是秒，也可以设置分钟小时

2、.Net4.0中：

 1 /// <summary>
 2         /// 正则解析
 3         /// </summary>
 4         /// <param name="regex">正则对象</param>
 5         /// <param name="input">需要解析的字符串</param>
 6         /// <param name="OutTimeMilliseconds">超时时间</param>
 7         /// <returns></returns>
 8         public static MatchCollection Matchs(Regex regex, string input, int OutTimeMilliseconds)
 9         {
10             MatchCollection mc = null;
11             AutoResetEvent are = new AutoResetEvent(false);
12             Thread t = new Thread(delegate()
13             {
14                 mc = regex.Matches(input);
15                 //注意,在这里一定要把所有的匹配项遍历一次,不然的话当在此方法外遍历的话.也可能会出现等待情况
16                 foreach (Match m in mc) { }
17                 are.Set();
18             });
19             t.Start();
20             Wait(t, TimeSpan.FromMilliseconds(OutTimeMilliseconds), are, null);
21             return mc;
22         }
23 
24         /// <summary>
25         /// 等待方法执行完成,或超时
26         /// </summary>
27         /// <param name="t"></param>
28         /// <param name="OutTime"></param>
29         /// <param name="ares"></param>
30         private static void Wait(Thread t, TimeSpan OutTime, WaitHandle are, WaitHandle cancelEvent)
31         {
32             WaitHandle[] ares;
33             if (cancelEvent == null)
34                 ares = new WaitHandle[] { are };
35             else
36                 ares = new WaitHandle[] { are, cancelEvent };
37             int index = WaitHandle.WaitAny(ares, OutTime);
38             if ((index != 0) && t.IsAlive)//如果不是执行完成的信号,并且,线程还在执行,那么,结束这个线程
39             {
40                 t.Abort();
41                 t = null;
42             }
43         }
44 
45         /// <summary>
46         /// 正则解析
47         /// </summary>
48         /// <param name="regex">正则对象</param>
49         /// <param name="input">需要解析的字符串</param>
50         /// <param name="OutTimeMilliseconds">超时时间</param>
51         /// <returns></returns>
52         public static Match Match(Regex regex, string input, int OutTimeMilliseconds)
53         {
54             Match m = null;
55             AutoResetEvent are = new AutoResetEvent(false);
56             Thread t = new Thread(delegate() { m = regex.Match(input); are.Set(); });
57             t.Start();
58             Wait(t, TimeSpan.FromMilliseconds(OutTimeMilliseconds), are, null);
59             return m;
60         }