示例程序:侦听某个文件夹中的FileSystem事件,并在Timer事件触发时将FileSystem事件信息打印到控制台。C#事件和线程
class Program
{
public static string location = @"D:\TestEvents";
public static double interval = 15000;
public static System.Timers.Timer timer;
public static List<string> listOfChanges = new List<string>();
static void Main(string[] args)
{
StartWatch();
StartTimer();
Console.ReadLine();
}
private static void StartWatch()
{
FileSystemWatcher Watcher = new FileSystemWatcher();
Watcher.Path = location;
Watcher.Created += new FileSystemEventHandler(OnFileCreatedOrDeleted);
Watcher.Deleted += new FileSystemEventHandler(OnFileCreatedOrDeleted);
Watcher.EnableRaisingEvents = true;
}
static void OnFileCreatedOrDeleted(object sender, FileSystemEventArgs e)
{
listOfChanges.Add(String.Format("Change Type: {0}, Name: {1}, Time: {2}", e.ChangeType, e.Name, DateTime.Now));
}
private static void StartTimer()
{
timer = new System.Timers.Timer();
timer.AutoReset = false;
timer.Elapsed += new System.Timers.ElapsedEventHandler(OnTimerEpleased);
timer.Interval = interval;
timer.Start();
}
private static void OnTimerEpleased(object sender, System.Timers.ElapsedEventArgs e)
{
Console.WriteLine("Timer event fired: " + DateTime.Now);
foreach (var item in listOfChanges)
{
Console.WriteLine(item);
}
Console.WriteLine();
listOfChanges.Clear();
timer.Interval = interval;
timer.Start();
}
}
从两个事件处理程序访问相同的存储静态List<string> listOfChanges
是否安全? 我不太了解事件如何在底下工作。是否创建了一些全局事件处理程序队列,并且尽管事件类型是一个接一个地运行所有事件处理程序?或者它为每个事件处理程序类型创建不同的线程?
编辑: 我想最好的解决办法是使用BlockingCollection
与ConcurrentQueue
,所以它应该是这样的:
public static BlockingCollection<string> listOfChanges = new BlockingCollection<string>();
static void OnFileCreatedOrDeleted(object sender, FileSystemEventArgs e)
{
listOfChanges.Add(String.Format("Change Type: {0}, Name: {1}, Time: {2}", e.ChangeType, e.Name, DateTime.Now));
}
private static void OnTimerEpleased(object sender, System.Timers.ElapsedEventArgs e)
{
Console.WriteLine("Timer event fired: " + DateTime.Now);
while (listOfChanges.Count > 0)
{
string item;
bool b = listOfChanges.TryTake(out item);
if (b)
{
Console.WriteLine(item);
}
}
Console.WriteLine();
timer.Interval = interval;
timer.Start();
}