比如在记事本或DW中，若有外部程序打开了某个文件，并进行了内容编辑及保存，若你当前正在打开本文件，则程序会弹出一个提示，告诉你文件被外部程序修改，是否恢复文件？或许平时你见的比较多吧？实现的方法是：利用API 函数FindFirstChangeNotification，可以用于监视指定目录下的文件系统变更情况，并可设置通知条件，函数返回的句柄被用于监视文件变更的线程。-

For example, in Notepad or DW, and if the external program to open a file, and content editing and saving, if you are currently open this file, the program will pop up a prompt that tells you that the file has been modified external program, whether recover files? Perhaps you usually see more of it? This is accomplished by: API function FindFirstChangeNotification, the file system can be used to monitor changes in circumstances specified directory, and set notification conditions, the function returns a handle to the thread being used to monitor file changes.