public Task <IEnumerable <PropertyDataCollection> > CollectAsync()
{
var tcs = new TaskCompletionSource <IEnumerable <PropertyDataCollection> >();
var watcher = new ManagementOperationObserver();
var results = new List <PropertyDataCollection>();
var readyHandler = new ObjectReadyEventHandler((sender, e) =>
{
results.Add(e.NewObject.Properties);
});
// The event handler that gets invoked by the watcher.
var completedHandler = default(CompletedEventHandler);
completedHandler = new CompletedEventHandler((sender, e) =>
{
var tcsLocal = tcs;
try
{
if (e.Status == ManagementStatus.NoError)
{
// The operation was completed without any errors.
tcsLocal.SetResult(results);
return;
}
if (e.Status == ManagementStatus.CallCanceled || e.Status == ManagementStatus.OperationCanceled)
{
// The task was cancelled before it could be completed.
tcsLocal.SetCanceled();
return;
}
// An exception occurred during the operation.
tcsLocal.SetException(new Exception($"Runtime error {e.Status}"));
return;
}
finally
{
// Clean up the event handlers.
watcher.Completed -= completedHandler;
}
});
// Wire up the event handler and begin the operation.
watcher.ObjectReady += readyHandler;
watcher.Completed += completedHandler;
var management = new ManagementClass("Win32_LogicalDisk");
management.GetInstances(watcher);
return(tcs.Task);
}
// Does the async version of the enumeration in a synchronous way (apparently the usual sync version blocks things weirdly)
public void EnumerateInstances(string queryString, ObjectReadyEventHandler myObserver)
{
AutoResetEvent finished = new AutoResetEvent(false);
ManagementObjectSearcher searcher = new ManagementObjectSearcher("root\\CIMV2", queryString);
ManagementOperationObserver observer = new ManagementOperationObserver();
observer.ObjectReady += myObserver;
observer.Completed += (sender, obj) => // CompletedEventHandler(object sender, CompletedEventArgs obj)
{
finished.Set();
};
searcher.Get(observer); // Asynchronous
finished.WaitOne();
return;
}
