I'm making a C# Pinger in WPF using Ping() and BackgroundWorker(). Here is my full code:
using System;
using System.ComponentModel;
using System.Net.NetworkInformation;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows;
using System.Windows.Media;
namespace Pinger
{
public partial class MainWindow : Window
{
[DllImport("wininet.dll")] private static extern bool InternetGetConnectedState(out int Description, int ReservedValue);
public static bool IsConnectedToInternet() { return InternetGetConnectedState(out _, 0); }
private readonly BackgroundWorker BackWork_Pinger = new BackgroundWorker();
private int counter = 0; private readonly Ping pinger = new Ping();
public MainWindow()
{
InitializeComponent();
BackWork_Pinger.WorkerReportsProgress = true;
BackWork_Pinger.DoWork = (_, args) => { for (int i = 1; i > 0; i) { if (IsConnectedToInternet()) { BackWork_Pinger.ReportProgress(i); Thread.Sleep(100); } } };
BackWork_Pinger.ProgressChanged = (_, args) =>
{
try
{
PingReply pingReply = pinger.Send("8.8.8.8");
if (pingReply != null)
{
switch (pingReply.Status)
{
case IPStatus.Success:
int PingNumber = Convert.ToInt32(pingReply.RoundtripTime);
if (PingNumber < 100) { Ping_Value.Foreground = Brushes.Lime; Ping_Value.Text = PingNumber " ms"; }
else if (PingNumber < 300) { Ping_Value.Foreground = Brushes.Yellow; Ping_Value.Text = PingNumber " ms"; }
else if (PingNumber < 500) { Ping_Value.Foreground = Brushes.DarkOrange; Ping_Value.Text = PingNumber " ms"; }
else { Ping_Value.Foreground = Brushes.Red; Ping_Value.Text = "Bad"; }
break;
case IPStatus.TimedOut: Ping_Value.Foreground = Brushes.WhiteSmoke; Ping_Value.Text = "Disconnected"; break;
default: Ping_Value.Foreground = Brushes.WhiteSmoke; Ping_Value.Text = "Disconnected"; break;
}
}
else { Ping_Value.Foreground = Brushes.WhiteSmoke; Ping_Value.Text = "Disconnected"; }
}
catch { Ping_Value.Foreground = Brushes.WhiteSmoke; Ping_Value.Text = "Disconnected"; }
Counter.Content = counter.ToString(); counter ;
};
BackWork_Pinger.RunWorkerAsync();
}
}
}
I wanna make a Pinger that works fine and not freezing my WinForm while disconnected or bad RoundTripTime. Is there any help to make a smooth pinger? or is there any demo project that i can modify from? Thank youuu :)
CodePudding user response：
Your problem here is your wrong implementation. You are misunderstanding the Backgroundworker. Backgroundworker.DoWork is executed on a background thread while Backgroundworker.ProgressChanged is executed on the main tread/UI thread. You are currently executing the long-running operation on the UI thread which results in freezing this thread. The solution is to execute the long-running operation in the DoWork handler.
You should use the modern Task library to implement the background task using Task.Run and report progress using the Progress<T> class. This way you have a clean and modern async way to replace the old event based Backgroundworker.
In case of the Ping class you should know that it already exposes an asynchronous API which you should use.
Instead of Ping.Send call Ping.SendAsync. This way you don't need a background thread any more.
Also make use of the PingOptions and timeout to add more robustness to your application.
Notice that Ping implements IDisposable: you probably need to take care of the object lifetime and call Dispose().
Your improved version looks as followed:
private CancellationTokenSource CancellationTokenSource { get; set; }
private Ping PingSender { get; }
private void OnCancelButtonClicked(object sender, EventArgs e)
{
// Abort
this.CancellationTokenSource.Cancel();
}
public void StartPingTarget(string ip)
{
this.CancellationTokenSource = new CancellationTokenSource();
CancellationToken cancellationToken = this.CancellationTokenSource.Token;
this.PingSender.PingCompleted = OnPingCompleted;
try
{
await PingIpAsync(ip, cancellationTokenSource);
}
catch (OperationCanceledException)
{
this.PingSender.SendAsyncCancel();
this.PingSender.PingCompleted -= OnPingCompleted;
// Optional: clean up/roll back
}
finally
{
this.CancellationTokenSource.Dispose();
}
}
private async Task PinIpAsync(
string ip,
CancellatioToken cancellationToken)
{
while (true)
{
await Task.Delay(TimeSpan.FromMilliSeconds(100, cancellationToken);
cancellationToken.ThrowIfCancellationRequested();
// Consider to use Pinoptions and a time-out to add more robustness
var options = new PingOptions (64, true);
byte[] buffer = new byte[0];
int timeoutInSeonds = (int) TimeSpan.FromSeconds(5).TotalMilliseconds;
await PingSender.SendAsync(ip, timeoutInSeonds, buffer, options, null);
}
}
private void PingCompletedCallback (object sender, PingCompletedEventArgs e)
{
SowProgress(e.Status, e.RoundtripTime);
}
private void ShowProgress(IPStatus pingStatus, long pingDuration)
{
Brush messageBrush = Brushes.WhiteSmoke;
string message = $"{pingDuration} ms";
switch (pingStatus)
{
case IPStatus.Success:
{
if (pingDuration < 100)
{
Ping_Value.Foreground = Brushes.Lime;
}
else if (pingDuration < 300)
{
messageBrush = Brushes.Yellow;
}
else if (pingDuration < 500)
{
messageBrush = Brushes.DarkOrange;
}
else
{
messageBrush = Brushes.Red;
message = "Bad";
}
break;
}
case IPStatus.TimedOut:
messageBrush = Brushes.WhiteSmoke;
message = "Disconnected";
break;
}
Ping_Value.Foreground = messageBrush;
Ping_Value.Text = message;
}
CodePudding user response：
BackgroundWorker call DoWork on parrale thread and callback ProgressChanged on UI thread. In your code, the ping is done on ProgressChanged, thus in the UI thread. When the UI thread work, the UI is freezed.
To avoid freezing the screen, it is necessary to execute the work on another thread. The ping must be in DoWork :
public MainWindow()
{
InitializeComponent();
BackWork_Pinger.WorkerReportsProgress = true;
BackWork_Pinger.DoWork = (_, args) =>
{
for (int i = 1; i > 0; i)
{
PingReply pingReply = null;
if (IsConnectedToInternet())
{
try
{
PingReply pingReply = pinger.Send("8.8.8.8");
}
catch
{ }
}
//Even if disconected
//Report progress and pause
BackWork_Pinger.ReportProgress(i, pingReply);
Thread.Sleep(100);
}
};
BackWork_Pinger.ProgressChanged = (_, args) =>
{
PingReply pingReply = pinger.Send("8.8.8.8");
if (pingReply != null)
{
...
}
else { Ping_Value.Foreground = Brushes.WhiteSmoke; Ping_Value.Text = "Disconnected"; } }
Counter.Content = counter.ToString(); counter ;
};
// Start the work when the windows is loaded
Loaded = (s, e) => { BackWork_Pinger.RunWorkerAsync(); };
// Else, the work's ProgressChanged can update Ping_Value before it's intanciated
}