Retrieving ping host name from SendPingAsync result

问题

I'm pinging hosts from list of strings (addresses). Everything works perfectly but when host is unreachable ping returns Result.Address: "0.0.0.0" instead of existing address or hostname which I passed into SendPingAsync function. Here is my code:

            var pingTasks = addresses.Select(address =>
            {
                return new Ping().SendPingAsync(address);
            });

            await Task.WhenAll(pingTasks);

            StringBuilder pingResultBuilder = new StringBuilder();

            foreach (var pingReply in pingTasks)
            {
                pingResultBuilder.Append(pingReply.Result.Address);
                pingResultBuilder.Append("    ");

                pingResultBuilder.Append(pingReply.Result.Status);
                pingResultBuilder.Append("    ");

                pingResultBuilder.Append(pingReply.Result.RoundtripTime.ToString());
                pingResultBuilder.AppendLine();
            }

            Console.WriteLine(pingResultBuilder.ToString());

I found solution here but I need to do the same thing in SendPingAsync function instead of SendAsync. How can I retrieve passed host name / ip address from pingReply.Result?

回答1:

You can write an extension method using SendAsync.

public static class MyExtensions
{
    public static Task<PingResult> SendTaskAsync(this Ping ping, string address)
    {
        var tcs = new TaskCompletionSource<PingResult>();
        PingCompletedEventHandler response = null;
        response = (s, e) =>
        {
            ping.PingCompleted -= response;
            tcs.SetResult(new PingResult() { Address = address, Reply = e.Reply });
        };
        ping.PingCompleted += response;
        ping.SendAsync(address, address);
        return tcs.Task;
    }

    public class PingResult
    {
        public string Address { set; get; }
        public PingReply Reply { set; get; }
    }
}

You can now use it like:

var pingTasks = addresses.Select(address =>
{
    return new Ping().SendTaskAsync(address);
});

var replies = await Task.WhenAll(pingTasks);

StringBuilder pingResultBuilder = new StringBuilder();

foreach (var pingReply in replies)
{
    pingResultBuilder.Append(pingReply.Address);
    pingResultBuilder.Append("    ");

    pingResultBuilder.Append(pingReply.Reply.Status);
    pingResultBuilder.Append("    ");

    pingResultBuilder.Append(pingReply.Reply.RoundtripTime.ToString());
    pingResultBuilder.AppendLine();
}

Console.WriteLine(pingResultBuilder.ToString());

来源：https://stackoverflow.com/questions/25534085/retrieving-ping-host-name-from-sendpingasync-result

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dns

ping