Develop Reference

How to get all installations when using Azure Notification Hubs installation model?

Using NotificationHubClient I can get all registered devices using GetAllRegistrationsAsync(). But if I do not use the registration model but the installation model instead, how can I get all installations? There are methods to retrieve a specific installation but none to get everything.

You're correct, as of July 2016 there's no way to get all installations for a hub. In the future, the product team is planning to add this feature to the installations model, but it will work in a different way. Instead of making it a runtime operation, you'll provide your storage connection string and you'll get a blob with everything associated with the hub.

Sorry for visiting an old thread... but in theory you could use the GetAllRegistrationsAsyc to get all the installations. I guess this will return everything without an installation id as well, but you could just ignore those if you choose.
Could look something like this
var allRegistrations = await _hub.GetAllRegistrationsAsync(0);
var continuationToken = allRegistrations.ContinuationToken;
var registrationDescriptionsList = new List<RegistrationDescription>(allRegistrations);
while (!string.IsNullOrWhiteSpace(continuationToken))
{
var otherRegistrations = await _hub.GetAllRegistrationsAsync(continuationToken, 0);
registrationDescriptionsList.AddRange(otherRegistrations);
continuationToken = otherRegistrations.ContinuationToken;
}
// Put into DeviceInstallation object
var deviceInstallationList = new List<DeviceInstallation>();
foreach (var registration in registrationDescriptionsList)
{
var deviceInstallation = new DeviceInstallation();
var tags = registration.Tags;
foreach(var tag in tags)
{
if (tag.Contains("InstallationId:"))
{
deviceInstallation.InstallationId = new Guid(tag.Substring(tag.IndexOf(":")+1));
}
}
deviceInstallation.PushHandle = registration.PnsHandle;
deviceInstallation.Tags = new List<string>(registration.Tags);
deviceInstallationList.Add(deviceInstallation);
}
I am not suggesting this to be the cleanest chunk of code written, but it does the trick for us. We only use this for debugging type purposes anyways

Async operation showing wrong file

I am trying to add an item to an ObservableCollection while in an aysnc operation. If I run the application, the collection does not have the correct file. If I step through it, I see the correct file does get added, which obviously shows a timing issue. Trouble is I cannot figure out how to fix it. Besides this, everything else works as I expect.
Can someone explain to me what I am doing wrong and how to fix it so the correct filename is written to the ObservableCollection?
private void ChangeFile(INotificationComplete notification)
{
FileInfo currentFileInfo = null;
var destinationImageFilename = string.Empty;
var imageDestinationFolder = Path.Combine(messageBrokerInstance.GetProgramPath("LevelThreeFilesWebLocation", this.SelectedPlatform), "images");
var fileDestinationFolder = Path.Combine(messageBrokerInstance.GetProgramPath("LevelThreeFilesWebLocation", this.SelectedPlatform));
try
{
Task.Factory.StartNew((Action)delegate
{
string[] files = null;
if (directoryInfo.Exists)
{
files = Directory.GetFiles(directoryInfo.FullName, #"*.htm", SearchOption.TopDirectoryOnly);
}
foreach (string file in files)
{
currentFileInfo = new FileInfo(file);
**// bunch of code
// I've found what I want and now am ready to write the file
// and add the filename to the collection the user sees.**
if (writeFile)
{
var fileDestination = Path.Combine(fileDestinationFolder, currentFileInfo.Name);
File.WriteAllLines(webFileDestination, fileArray);
**// Correct file was written but the wrong filename
// is added to the collection.**
// If I step through this, the correct filename is added.
UIDispatcher.Current.BeginInvoke((Action)delegate
{
this.ChangedFiles.Add(currentFileInfo.Name); // ChangedFiles is an ObservableCollection<string>
});
}
}
WaitAnimationNotification offNotification = new WaitAnimationNotification()
{
IsWaitAnimationOn = false,
WaitAnimationMessage = "Please wait while the operation completes..."
};
WaitAnimationNotification waitNotification = notification as WaitAnimationNotification;
if (waitNotification.IsWaitAnimationOn)
{
this.SendMessage("ToggleWaitAnimation", new NotificationEventArgs<WaitAnimationNotification, INotificationComplete>("ToggleWaitAnimation", offNotification));
}
});
}
}

I dont know what UIDispatcher.Current is, but the correct Dispatcher to use is Application.Current.Dispatcher It's easy to spin up a separate dispatcher on a background thread unintentionally - which will give you the behavior you see. Application.Current.Dispatcher is going to be the correct dispatcher for the main application message pump

DisconnectedContext detected when using STA thread to modify SharePoint page

Background Info: I'm using an ItemCheckedIn receiver in SharePoint 2010, targeting .NET 3.5 Framework. The goal of the receiver is to:
Make sure the properties (columns) of the page match the data in a Content Editor WebPart on the page so that the page can be found in a search using Filter web parts. The pages are automatically generated, so barring any errors they are guaranteed to fit the expected format.
If there is a mismatch, check out the page, fix the properties, then check it back in.
I've kept the receiver from falling into an infinite check-in/check-out loop, although right now it's a very clumsy fix that I'm trying to work on. However, right now I can't work on it because I'm getting a DisconnectedContext error whenever I hit the UpdatePage function:
public override void ItemCheckedIn(SPItemEventProperties properties)
{
// If the main page or machine information is being checked in, do nothing
if (properties.AfterUrl.Contains("home") || properties.AfterUrl.Contains("machines")) return;
// Otherwise make sure that the page properties reflect any changes that may have been made
using (SPSite site = new SPSite("http://san1web.net.jbtc.com/sites/depts/VPC/"))
using (SPWeb web = site.OpenWeb())
{
SPFile page = web.GetFile(properties.AfterUrl);
// Make sure the event receiver doesn't get called infinitely by checking version history
...
UpdatePage(page);
}
}
private static void UpdatePage(SPFile page)
{
bool checkOut = false;
var th = new Thread(() =>
{
using (WebBrowser wb = new WebBrowser())
using (SPLimitedWebPartManager manager = page.GetLimitedWebPartManager(PersonalizationScope.Shared))
{
// Get web part's contents into HtmlDocument
ContentEditorWebPart cewp = (ContentEditorWebPart)manager.WebParts[0];
HtmlDocument htmlDoc;
wb.Navigate("about:blank");
htmlDoc = wb.Document;
htmlDoc.OpenNew(true);
htmlDoc.Write(cewp.Content.InnerText);
foreach (var prop in props)
{
// Check that each property matches the information on the page
string element;
try
{
element = htmlDoc.GetElementById(prop).InnerText;
}
catch (NullReferenceException)
{
break;
}
if (!element.Equals(page.GetProperty(prop).ToString()))
{
if (!prop.Contains("Request"))
{
checkOut = true;
break;
}
else if (!element.Equals(page.GetProperty(prop).ToString().Split(' ')[0]))
{
checkOut = true;
break;
}
}
}
if (!checkOut) return;
// If there was a mismatch, check the page out and fix the properties
page.CheckOut();
foreach (var prop in props)
{
page.SetProperty(prop, htmlDoc.GetElementById(prop).InnerText);
page.Item[prop] = htmlDoc.GetElementById(prop).InnerText;
try
{
page.Update();
}
catch
{
page.SetProperty(prop, Convert.ToDateTime(htmlDoc.GetElementById(prop).InnerText).AddDays(1));
page.Item[prop] = Convert.ToDateTime(htmlDoc.GetElementById(prop).InnerText).AddDays(1);
page.Update();
}
}
page.CheckIn("");
}
});
th.SetApartmentState(ApartmentState.STA);
th.Start();
}
From what I understand, using a WebBrowser is the only way to fill an HtmlDocument in this version of .NET, so that's why I have to use this thread.
In addition, I've done some reading and it looks like the DisconnectedContext error has to do with threading and COM, which are subjects I know next to nothing about. What can I do to prevent/fix this error?
EDIT
As #Yevgeniy.Chernobrivets pointed out in the comments, I could insert an editable field bound to the page column and not worry about parsing any html, but because the current page layout uses an HTML table within a Content Editor WebPart, where this kind of field wouldn't work properly, I'd need to make a new page layout and rebuild my solution from the bottom up, which I would really rather avoid.
I'd also like to avoid downloading anything, as the company I work for normally doesn't allow the use of unapproved software.

You shouldn't do html parsing with WebBrowser class which is part of Windows Forms and is not suited for web as well as for pure html parsing. Try using some html parser like HtmlAgilityPack instead.

Getting an unauthorisedAccessException due to deserialisation. c#/Windows phone 8.1

So, I'm developing a contact management system and I'm trying to add a contact. Instead of jumping between ViewModels(the contact and main contact page are separate), I've decided to take in data from the view, create a contact, add it to a list then serialize that list. Then, when I get back to the main page, I deserialize that list.
This works fine(no optimization, this is just a simple college project) as the data is added to the JSON file. My problem is- when I navigate back to the main page- the list doesn't update due to an UnauthorisedAccessException on my stream. The deserialization method is:
private async void buildMyListWithJsonAsync(){
ObservableCollection<Contact> list = new ObservableCollection<Contact>();
try
{
string JSONFILENAME = "contacts.json";
string content = " ";
StorageFile File = await ApplicationData.Current.LocalFolder.GetFileAsync(JSONFILENAME);
using (IRandomAccessStream testStream = await File.OpenAsync(FileAccessMode.Read)){
using (DataReader dreader = new DataReader(testStream)){
uint length = (uint)testStream.Size;
await dreader.LoadAsync(length);
content = dreader.ReadString(length);
list = JsonConvert.DeserializeObject<ObservableCollection<Contact>>(content);
}
}
contactlist = new ObservableCollection<Contact>();
foreach (Contact c in list)
contactlist.Add(c);
}
catch (Exception e)
{ e.ToString(); }
}
Any help or aid would be appreciated.

I'd hazard an educated guess that the issue is around threading and your ObservableCollection. ObservableCollections aren't threadsafe and involve raising events on the UI thread they're created on typically & StorageFile API is all async thread based.
Have a shot at pulling the string back from the async thread and doing the Serialization and Deserialization on the main UI thread instead and that may well resolve it.

Adding AsParallel() call cause my code to break on writing a file

I'm building a console application that have to process a bunch of document.
To stay simple, the process is :
for each year between X and Y, query the DB to get a list of document reference to process
for each of this reference, process a local file
The process method is, I think, independent and should be parallelized as soon as input args are different :
private static bool ProcessDocument(
DocumentsDataset.DocumentsRow d,
string langCode
)
{
try
{
var htmFileName = d.UniqueDocRef.Trim() + langCode + ".htm";
var htmFullPath = Path.Combine("x:\path", htmFileName;
missingHtmlFile = !File.Exists(htmFullPath);
if (!missingHtmlFile)
{
var html = File.ReadAllText(htmFullPath);
// ProcessHtml is quite long : it use a regex search for a list of reference
// which are other documents, then sends the result to a custom WS
ProcessHtml(ref html);
File.WriteAllText(htmFullPath, html);
}
return true;
}
catch (Exception exc)
{
Trace.TraceError("{0,8}Fail processing {1} : {2}","[FATAL]", d.UniqueDocRef, exc.ToString());
return false;
}
}
In order to enumerate my document, I have this method :
private static IEnumerable<DocumentsDataset.DocumentsRow> EnumerateDocuments()
{
return Enumerable.Range(1990, 2020 - 1990).AsParallel().SelectMany(year => {
return Document.FindAll((short)year).Documents;
});
}
Document is a business class that wrap the retrieval of documents. The output of this method is a typed dataset (I'm returning the Documents table). The method is waiting for a year and I'm sure a document can't be returned by more than one year (year is part of the key actually).
Note the use of AsParallel() here, but I never got issue with this one.
Now, my main method is :
var documents = EnumerateDocuments();
var result = documents.Select(d => {
bool success = true;
foreach (var langCode in new string[] { "-e","-f" })
{
success &= ProcessDocument(d, langCode);
}
return new {
d.UniqueDocRef,
success
};
});
using (var sw = File.CreateText("summary.csv"))
{
sw.WriteLine("Level;UniqueDocRef");
foreach (var item in result)
{
string level;
if (!item.success) level = "[ERROR]";
else level = "[OK]";
sw.WriteLine(
"{0};{1}",
level,
item.UniqueDocRef
);
//sw.WriteLine(item);
}
}
This method works as expected under this form. However, if I replace
var documents = EnumerateDocuments();
by
var documents = EnumerateDocuments().AsParrallel();
It stops to work, and I don't understand why.
The error appears exactly here (in my process method):
File.WriteAllText(htmFullPath, html);
It tells me that the file is already opened by another program.
I don't understand what can cause my program not to works as expected. As my documents variable is an IEnumerable returning unique values, why my process method is breaking ?
thx for advises
[Edit] Code for retrieving document :
/// <summary>
/// Get all documents in data store
/// </summary>
public static DocumentsDS FindAll(short? year)
{
Database db = DatabaseFactory.CreateDatabase(connStringName); // MS Entlib
DbCommand cm = db.GetStoredProcCommand("Document_Select");
if (year.HasValue) db.AddInParameter(cm, "Year", DbType.Int16, year.Value);
string[] tableNames = { "Documents", "Years" };
DocumentsDS ds = new DocumentsDS();
db.LoadDataSet(cm, ds, tableNames);
return ds;
}
[Edit2] Possible source of my issue, thanks to mquander. If I wrote :
var test = EnumerateDocuments().AsParallel().Select(d => d.UniqueDocRef);
var testGr = test.GroupBy(d => d).Select(d => new { d.Key, Count = d.Count() }).Where(c=>c.Count>1);
var testLst = testGr.ToList();
Console.WriteLine(testLst.Where(x => x.Count == 1).Count());
Console.WriteLine(testLst.Where(x => x.Count > 1).Count());
I get this result :
0
1758
Removing the AsParallel returns the same output.
Conclusion : my EnumerateDocuments have something wrong and returns twice each documents.
Have to dive here I think
This is probably my source enumeration in cause

I suggest you to have each task put the file data into a global queue and have a parallel thread take writing requests from the queue and do the actual writing.
Anyway, the performance of writing in parallel on a single disk is much worse than writing sequentially, because the disk needs to spin to seek the next writing location, so you are just bouncing the disk around between seeks. It's better to do the writes sequentially.

Is Document.FindAll((short)year).Documents threadsafe? Because the difference between the first and the second version is that in the second (broken) version, this call is running multiple times concurrently. That could plausibly be the cause of the issue.

Sounds like you're trying to write to the same file. Only one thread/program can write to a file at a given time, so you can't use Parallel.
If you're reading from the same file, then you need to open the file with only read permissions as not to put a write lock on it.
The simplest way to fix the issue is to place a lock around your File.WriteAllText, assuming the writing is fast and it's worth parallelizing the rest of the code.