如何在C#中转义while循环

Question

我试图逃避一个循环.基本上,如果满足"if"条件,我希望能够退出此循环:

private void CheckLog()
{
    while (true)
    {
        Thread.Sleep(5000);
        if (!System.IO.File.Exists("Command.bat"))
            continue;

        using (System.IO.StreamReader sr = System.IO.File.OpenText("Command.bat"))
        {
            string s = "";
            while ((s = sr.ReadLine()) != null)
            {
                if (s.Contains("mp4:production/CATCHUP/"))
                {
                    RemoveEXELog();

                    Process p = new Process();
                    p.StartInfo.WorkingDirectory = "dump";
                    p.StartInfo.FileName = "test.exe";
                    p.StartInfo.Arguments = s;
                    p.Start();

                    << Escape here - if the "if" condition is met, escape the loop here >>
                }
            }
        }
    }
}

Answer 1

使用break;逃脱第一循环:

if (s.Contains("mp4:production/CATCHUP/"))
{
   RemoveEXELog();
   Process p = new Process();
   p.StartInfo.WorkingDirectory = "dump";
   p.StartInfo.FileName = "test.exe"; 
   p.StartInfo.Arguments = s; 
   p.Start();
   break;
}

如果你想要转义第二个循环,你可能需要使用一个标志并检查out循环的守卫:

        boolean breakFlag = false;
        while (!breakFlag)
        {
            Thread.Sleep(5000);
            if (!System.IO.File.Exists("Command.bat")) continue;
            using (System.IO.StreamReader sr = System.IO.File.OpenText("Command.bat"))
            {
                string s = "";
                while ((s = sr.ReadLine()) != null)
                {
                    if (s.Contains("mp4:production/CATCHUP/"))
                    {

                        RemoveEXELog();

                        Process p = new Process();
                        p.StartInfo.WorkingDirectory = "dump";
                        p.StartInfo.FileName = "test.exe"; 
                        p.StartInfo.Arguments = s; 
                        p.Start();

                        breakFlag = true;
                        break;
                    }
                }
            }

或者,如果您只想从嵌套循环中完全退出函数,请输入return;而不是a break;.

但这些并不是最佳实践.您应该找到一些方法将必要的布尔逻辑添加到您的while警卫中.

Answer 2

break 要么 goto

while ( true ) {
  if ( conditional ) {
    break;
  }
  if ( other conditional ) {
    goto EndWhile;
  }
}
EndWhile:

Answer 3

但您可能还希望研究一种非常不同的方法,即侦听文件系统事件.