DispatchSource.ReadMonitor 類別

var stream = File.OpenRead ("Demo.txt");

// The the unix file handle
var safeHandle = stream.SafeFileHandle;
IntPtr descriptor = safeHandle.DangerousGetHandle ();
int fileDescriptor = descriptor.ToInt32 ();

dispatchSource = new DispatchSource.ReadMonitor (fileDescriptor, DispatchQueue.MainQueue);

dispatchSource.SetRegistrationHandler (() => {
    Console.WriteLine ("Read monitor registered");
});

dispatchSource.SetEventHandler (() => {
    Console.WriteLine ("Read monitor: was opened in write mode")
    dispatchSource.Cancel ();
    stream.Close ();
});

dispatchSource.SetCancelHandler (() => {
    Console.WriteLine ("Read monitor cancelled");
});

dispatchSource.Resume ();