| ● ここまでの結論
Main2を別スレッドで動作させることで waiter.WaitOne(); を待っているときのイベントは発生するようになりました。
これがベストかどうかはわかりません。
● 考察
Windowsアプリケーションではbutton1をクリックしてMain2を実行したときに PingCompletedCallback は発生するのですが，Main2が終了するまでそのイベント・ハンドラは実行できないようです。このためMain2を別スレッドで実行する必要があるようです。
また，ThreadStartではパラメタを渡すことができないそうです。
動作確認したコードを示します。
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.NetworkInformation;
using System.Threading;
namespace win_ping_sample03 {
public partial class Form1 : Form {
private Thread thMain;
public Form1() {
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e) {
Thread thMain = new Thread(new ThreadStart(this.Main2));
thMain.IsBackground = true;
thMain.Start();
}
//public void Main2(string[] args) {
public void Main2() {
//if (args.Length == 0)
// throw new ArgumentException("Ping needs a host or IP Address.");
//string who = args[0];
string who = "192.168.2.1";
AutoResetEvent waiter = new AutoResetEvent(false);
Ping pingSender = new Ping();
// When the PingCompleted event is raised,
// the PingCompletedCallback method is called.
pingSender.PingCompleted += new PingCompletedEventHandler(PingCompletedCallback);
// Create a buffer of 32 bytes of data to be transmitted.
string data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
byte[] buffer = Encoding.ASCII.GetBytes(data);
// Wait 12 seconds for a reply.
int timeout = 12000;
// Set options for transmission:
// The data can go through 64 gateways or routers
// before it is destroyed, and the data packet
// cannot be fragmented.
PingOptions options = new PingOptions(64, true);
Console.WriteLine("Time to live: {0}", options.Ttl);
Console.WriteLine("Don't fragment: {0}", options.DontFragment);
// Send the ping asynchronously.
// Use the waiter as the user token.
// When the callback completes, it can wake up this thread.
pingSender.SendAsync(who, timeout, buffer, options, waiter);
// Prevent this example application from ending.
// A real application should do something useful
// when possible.
waiter.WaitOne();
Console.WriteLine("Ping example completed.");
}
public static void PingCompletedCallback(object sender, PingCompletedEventArgs e) {
// If the operation was canceled, display a message to the user.
if (e.Cancelled) {
Console.WriteLine("Ping canceled.");
// Let the main thread resume.
// UserToken is the AutoResetEvent object that the main thread
// is waiting for.
((AutoResetEvent)e.UserState).Set();
}
// If an error occurred, display the exception to the user.
if (e.Error != null) {
Console.WriteLine("Ping failed:");
Console.WriteLine(e.Error.ToString());
// Let the main thread resume.
((AutoResetEvent)e.UserState).Set();
}
PingReply reply = e.Reply;
DisplayReply(reply);
// Let the main thread resume.
((AutoResetEvent)e.UserState).Set();
}
public static void DisplayReply(PingReply reply) {
if (reply == null)
return;
Console.WriteLine("ping status: {0}", reply.Status);
if (reply.Status == IPStatus.Success) {
Console.WriteLine("Address: {0}", reply.Address.ToString());
Console.WriteLine("RoundTrip time: {0}", reply.RoundtripTime);
Console.WriteLine("Time to live: {0}", reply.Options.Ttl);
Console.WriteLine("Don't fragment: {0}", reply.Options.DontFragment);
Console.WriteLine("Buffer size: {0}", reply.Buffer.Length);
}
}
}
} |