// 设置取消回调，来兼容老的api
async Task <int> PingAsync(CancellationToken cancellation)
{
var ping = new Ping();
// 这些回调会轮流保持Ping对象的生命，为了避免内存及资源的溢出，当不再需要回调时，必须丢弃回调注册
using var _ = cancellation.Register(() => ping.Cancel()); //设置取消的回调
return(await Task.FromResult(1));
}
private static void RunPing()
{
try
{
_ping1 = ExternalLib.Request.Ping(new string[] { "2.16.840.1.114416.0.57513008" });
RequestStatusChangedItem item = _ping1.Execute(TimeSpan.FromSeconds(30));
if (null == item)
{
_ping1.Cancel();
}
}
catch (Exception ex)
{
Console.WriteLine("RunPing: " + ex.Message);
}
}