thank TimonYang.

1.First ,I copy all code and run but nothing happen and listView not show anything but no error.
2.I change the code at "var watcher = new FileSystemWatcher(@"C:\");" because drive C:\ should be monitor.

 The Error is;
System.IO.IOException
  HResult=0x80070020
  Message=The process cannot access the file 'C:\Users\family\AppData\Local\Microsoft\VSApplicationInsights\vstelAIF-312cbd79-9dbb-4c48-a7da-3cc2a931cb70\20210410124403_36d29eaa2886438fb8ea9e0d779de559.trn' because it is being used by another process.
  Source=mscorlib
  StackTrace:
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.StreamWriter.CreateFile(String path, Boolean append, Boolean checkHost)
   at System.IO.StreamWriter..ctor(String path, Boolean append, Encoding encoding, Int32 bufferSize, Boolean checkHost)
   at System.IO.StreamWriter..ctor(String path)
   at LearningC_13.Form1.OnRenamed(Object sender, RenamedEventArgs e) in C:\Users\family\source\repos\LearningC_13\LearningC_13\Form1.cs:line 65
   at System.IO.FileSystemWatcher.OnRenamed(RenamedEventArgs e)
   at System.IO.FileSystemWatcher.NotifyRenameEventArgs(WatcherChangeTypes action, String name, String oldName)
   at System.IO.FileSystemWatcher.CompletionStatusChanged(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* overlappedPointer)
   at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP)