I am using async method in my Windows 8 development. but it is not updating the UI until it finishes executing full method.
here is my code.
below method calls when user presses refresh button on screen.
public async override void ExceuteRefresh()
{
IsBusy = true; //This is bounded to my UI to show progress bar, but its not updating to UI
foreach (var category in CategoryObservableColl)
{
CheckforOnlineUpdatesAsync(category, true);
}
}
private async void CheckforOnlineUpdatesAsync(Category category, bool isReFresh)
{
var feed = await _dataService.GetOnlineRssFeedAsync(category.RssFeedLink.URL);
var newsCategory = _dataService.GetCategoryFromFeed(feed, true, category.RssFeedLink);
if (newsCategory != null)
{
isRefreshCount +=1;
}
if(isRefreshCount ==9)
{
IsBusy = false;
}
}
IsBusy has implemented InotifyPropertyChanged.
Any help would be greatly appreciated. tried following approach.
public override async void ExceuteRefresh()
{
await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () => IsBusy = true);
_reloadCategories = false;
_refreshLinkCount = 0;
try
{
foreach (var category in CategoryObservableColl)
{
_refreshLinkCount += 1;
await CheckforOnlineUpdatesAsync(category, true);
}
}
catch (Exception ex)
{
MainPage.ShowMessage("Something Went wrong!. " + ex.Message);
}
}
Also made following method return type as task.
private async Task CheckforOnlineUpdatesAsync(Category category, bool isReFresh)
{
}
Thanks in advance
Try this
Change async void CheckforOnlineUpdatesAsync(...) to async Task CheckforOnlineUpdatesAsync(...)
Change method call to await CheckforOnlineUpdatesAsync(category, true);
Change public async override void ExceuteRefresh() to public async override Task ExceuteRefresh()
Replace IsBusy = false; to below given code. You need to use UI thread to update the UI.
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () => IsBusy = false);
Related
I have been working on a device which is sending some data to an Azure IoT hub
The device is doing this on two different locations in the code. On one side it works perfectly and I can connect to the Hub via Connection String and transport type MQTT_WebSocket_Only.
public static class Mqtt2IoTNew
{
private static string _DeviceConnectionString = Properties.Settings.Default.MqttUri;
private static TransportType _TransportType = TransportType.Mqtt_WebSocket_Only;
public static void Send(object argEntry, bool argIsList)
{
var deviceClient = DeviceClient.CreateFromConnectionString(_DeviceConnectionString, _TransportType);
deviceClient.ReceiveAsync(TimeSpan.FromSeconds(2)).Wait();
var message = new Message(deviceClient, argEntry, argIsList);
message.RunAsync().GetAwaiter().GetResult();
}
}
internal class Message
{
private DeviceClient _DeviceClient;
private readonly string _Message;
public Message(DeviceClient argDeviceClient, object argEntry, bool isList)
{
_DeviceClient = argDeviceClient;
StringBuilder stb = new StringBuilder();
if (isList)
{
foreach (var entity in (List<object>) argEntry)
{
stb.Append("<entity>").Append(JsonConvert.SerializeObject(entity)).Append("</entity>\n");
}
}
else
{
stb.Append(JsonConvert.SerializeObject(argEntry));
}
_Message = stb.ToString();
}
public async Task RunAsync()
{
await SendEvent().ConfigureAwait(false);
}
private async Task SendEvent()
{
Microsoft.Azure.Devices.Client.Message eventMessage = new Microsoft.Azure.Devices.Client.Message(Encoding.UTF8.GetBytes(_Message));
await _DeviceClient.SendEventAsync(eventMessage).ConfigureAwait(false);
}
}
//Call of method that does not work
protected override void DoOnCompleted(IRepository argRepository)
{
if (_CurrentlySendingTreadId.HasValue)
{
if (_CurrentlySendingTreadId.Value == Thread.CurrentThread.ManagedThreadId)
{
return;
}
}
TaskFactoryProvider.GetFactory().StartNew(()=>SendBatchProtocols());
}
public bool SendBatchProtocols()
{
using (var repository = RepositoryProviderHolder.RepositoryProvider.GetRepository(Constants.CONTAINERCONTRACT_PRODUCTIONREPOSITORY))
{
IQueryable<BatchProtocol> batchProtocolQuery = repository.GetQuery<BatchProtocol>().OrderBy(bp => bp.InternalNoInteger);
batchProtocolQuery = batchProtocolQuery.Where(bp => !bp.IsArchived).Take(1);
if (!batchProtocolQuery.Any()) return false;
var batchProtocols = batchProtocolQuery.ToList();
IsBatchProtocolSend = false;
try
{
foreach (var bps in batchProtocols)
{
Mqtt2IoTNew.Send(bps,false);
}
IsBatchProtocolSend = true;
}
catch (Exception ex)
{
throw;
}
}
return IsBatchProtocolSend;
}
//Call of Method that does work
private void AddEntitiesAndSaveChanges(IEnumerable argEntities)
{
if (argEntities == null)
{
return;
}
lock (_UnderlyingRepositoryAccessLockObject)
{
#region Log2DornerIoT
if (Properties.Settings.Default.Log2DornerIoT)
{
List<object> entities = new List<object>();
int i = 0;
foreach (var entity in argEntities)
{
if (i < 100)
{
entities.Add(entity);
i++;
}
else
{
try
{
Mqtt2IoTNew.Send(entities, true);
}
catch (Exception e)
{
throw;
}
entities.Clear();
i = 0;
}
}
}
}
on the other part of the code, I am only colling the same class to use to send method in the same way but here I get an exception which says "TLS authentication error" and the inner exception "Unable to connect to the remote server", "The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel".
But: I never used any kind of authorization not in the first part which works perfectly neither in the second.
I would be very happy if someone could help me. I have found nothing so fare regarding this issue.
Thanks for your time.
Michael
I found the reason why it didn't work. There was a Persmissice Certificate Policy applied that blocked the certificate at one side of the project. I disabled it and now it works perfectly fine.
Thanks for the help anyway.
I'm doing a desktop application and I'm performing a heavy task in background. I want a progress bar to be updated. My program works and I can see the progress bar here isn't my problem. My problem is that I use 2 tasks that I run in 2 thread in order to make both the update of the progress bar and the heavy task. My question is : Is there a better way to do in oder to avoid the error "Exception in thread "Thread-5" java.lang.IllegalStateException: Not on FX application thread; currentThread = Thread-5".
Of course I already check on Internet and I always find : better use Platform.runLater. Ok but in both new thread I need attribute of my class, eg I can't access for example "this.myAttribute" when I use Platform.runLater((new Runnable()...)). Is RunLater the solution and I can't see it ?
Here is a bunch of code, the method setConnection is called in JavaFX thread, and I create 2 other. One for progressbar, the other for my task :
#FXML
private void setConnection() {
try {
this.onOffButton.setSelected(false);
if (!this.hubModel.isConnected()) {
this.progressBar.progressProperty().unbind();
#SuppressWarnings("unchecked")
OperationTask progressBarOperationTask = new OperationTask(this) {
#Override
public Void call() {
HubController hubController = (HubController) this.getHubController();
hubController.getProgressBar().setVisible(true);
for (int i = 0; i < 100; i++) {
try {
Thread.sleep(25);
} catch (InterruptedException e) {
Thread.interrupted();
break;
}
updateProgress(i + 1, 100);
}
hubController.getProgressBar().setVisible(false);
return null;
}
};
this.progressBar.progressProperty().bind(progressBarOperationTask.progressProperty());
Thread timeThread = new Thread(progressBarOperationTask);
timeThread.setDaemon(true);
timeThread.start();
}
#SuppressWarnings("unchecked")
OperationTask connectionOperationTask = new OperationTask(this) {
#Override
protected Object call() throws Exception {
HubController hubController = (HubController) this.getHubController();
if (hubController.getUserID().getText().equals("") || hubController.getUserPW().getText().equals("")) {
hubController.getCommentBottom().setText("Please enter a user name and a password.");
hubController.getOnOffButton().setSelected(false);
} else {
hubController.getHubModel().setIdUser(hubController.getUserID().getText());
hubController.getHubModel().setPwUser(hubController.getUserPW().getText());
String comment = hubController.getHubModel().setConnection();
if (!comment.equals("Connection established.")) {
hubController.getOnOffButton().setSelected(false);
}
if (hubController.getHubModel().isConnected()) {
hubController.getConnectionStatus().setText("Connected");
hubController.getConnectionStatus().setStyle("-fx-font-weight: bold");
String commentProject = hubController.getHubModel().getAllProjects();
if (commentProject.equals("")) {
TextFields.bindAutoCompletion(hubController.getCloneAndMoveController().getNewProjectNameTextField(), hubController.getHubModel().getProjectsList());
} else {
comment = commentProject;
}
hubController.getOnOffButton().setSelected(true);
} else {
hubController.getConnectionStatus().setText("Not connected");
hubController.getConnectionStatus().setStyle("-fx-font-weight: regular");
}
hubController.getCommentBottom().setText(comment);
}
return null;
}
};
Thread connectionThread = new Thread(connectionOperationTask);
connectionThread.setDaemon(true);
connectionThread.start();
} catch (Exception e) {
e.printStackTrace();
}
}
Moreover if you see something that could be improved, I would appreciate (I'm new with java)
Thank you.
You can access your object from Platform.runLater(). New Runnable which you create for it has access to this instance of your object. See in an example:
private String myAttribute = "hello";
#Override
public void randomMethod() {
//...
Platform.runLater(new Runnable() {
#Override
public void run() {
System.out.println(myAttribute);
}
});
}
My problem is that I can not start a new modal window in Task, it just does not go out. I do not understand how it is possible to derive not just an allert, but any modal window from Task. Translated by Google =)
Task<Void> task = new Task<Void>() {
#Override
public Void call() throws ApiException,ClientException,InterruptedException {
int i = 0;
for ( i = 0; i < bufferLenght; i++){
try {
...some code
}catch(ApiCaptchaException e) {
...get capcha
captchaSid = e.getSid();
captchaImg = e.getImage();
System.out.println( captchaSid);
}
System.out.println(captchaSid);
if (captchaSid != null) {
System.out.println("gg");
Alert alert = new Alert(AlertType.INFORMATION);
alert.setTitle("Test Connection");
//here he is stuck
alert.setHeaderText("Results:");
alert.setContentText("Connect to the database successfully!");
alert.showAndWait();
System.out.println("gg3");
if(i<bufferLenght-1) {
Thread.sleep(2000);
}
}
return null;
}
};
new Thread(task).start();
You must create and show new windows on the FX Application Thread. You can schedule code to execute on the FX Application Thread by submitting it to Platform.runLater(...). If you need your background thread to wait for the user to dismiss the Alert, you can use a CompletableFuture, as in this question:
Task<Void> task = new Task<Void>() {
#Override
protected Void call() throws Exception {
// ...
CompletableFuture.runAsync(() -> {
Alert alert = new Alert(AlertType.INFORMATION);
alert.setTitle("Test Connection");
alert.setHeaderText("Results:");
alert.setContentText("Connect to the database successfully!");
alert.showAndWait();
}, Platform::runLater).join();
// ...
}
};
If your alert is returning a value which you need, use supplyAsync(...) instead and return the value from the lambda expression. You can then assign that value to the result of join():
Task<Void> task = new Task<Void>() {
#Override
protected Void call() throws Exception {
// ...
String result = CompletableFuture.supplyAsync(() -> {
Alert alert = new Alert(AlertType.INFORMATION);
alert.setTitle("Test Connection");
alert.setHeaderText("Results:");
alert.setContentText("Connect to the database successfully!");
alert.showAndWait();
// presumably here you want to return a string
// depending on the alert...
return "" ;
}, Platform::runLater).join();
// ...
}
};
I need help with creating a windows service using Threading and asynchronous HttpWebRequest calls. I have created a few C# windows services before but never using threading. Also, I seem to be getting hung up with the async calls using HttpWebRequest. I have googled this as well as looking on this site. I could not find anything that helped. This is mainly because I could not seem to get what was presented in other questions to work in my specific example.
Please keep in mind that I may be overlapping things based on my lack of knowledge in this specific area as well as through trying to figure it out.
The main flow of this is to get a list of urls during onStart. Typically this list would be retrieved from a _facade.GetUrls call. Then, at each time interval call scanSites. A request is made to each url and then I save the results to the database in _facade.SaveUrlResponse.
My problems is it seems as if I am caught in an endless loop when I debug it. I am not exactly sure how/where to do this. Thanks in advance.
Here is what I have:
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Net;
using System.ServiceProcess;
using System.Threading;
using URLValidation.BusinessManager.Facade;
using URLValidation.BusinessManager.Model;
namespace URLValidation
{
partial class URLValidation : ServiceBase
{
#region " class variables "
private System.Timers.Timer _timer;
private List<UrlModel> _url_List = null;
private Facade _facade;
private Thread _t;
private int _x;
#endregion
public URLValidation()
{
_facade = new Facade();
InitializeComponent();
}
protected override void OnStart(string[] args)
{
try
{
_url_List = new List<UrlModel>
{
new UrlModel(address: "http://www.google.com", addressID: 1),
new UrlModel(address: "http://www.microsoft.com", addressID: 2),
new UrlModel(address: "http://www.stackoverflow.com", addressID: 3)
};
resetTimer();
GC.KeepAlive(_timer);
}
catch (Exception ex)
{
throw ex;
}
}
private void resetTimer()
{
try
{
_timer = new System.Timers.Timer();
_timer.Interval = 10000;//1800000; //30 minutes
_timer.Start();
_timer.Enabled = true;
_timer.Elapsed += scanSites;
}
catch (Exception ex)
{
throw ex;
}
}
private void scanSites(object sender, System.Timers.ElapsedEventArgs e)
{
_timer.Stop();
_x = 0;
_t = new Thread(new ThreadStart(scanSites));
_t.IsBackground = true;
_t.Start();
}
private void scanSites()
{
try
{
foreach (UrlModel url in _url_List)
{
_x += 1;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url.Address);
request.Method = "HEAD";
RequestModel requestModel = new RequestModel(request, url);
IAsyncResult result = request.BeginGetResponse(new AsyncCallback(saveUrlResponse), requestModel);
ThreadPool.RegisterWaitForSingleObject
(
result.AsyncWaitHandle,
new WaitOrTimerCallback(ScanTimeoutCallback),
requestModel,
(30 * 1000), // 30 second timeout
true
);
}
}
catch (Exception ex)
{
throw ex;
}
}
private void saveUrlResponse(IAsyncResult result)
{
//grab the custom state object
RequestModel requestModel = (RequestModel)result.AsyncState;
HttpWebRequest request = (HttpWebRequest)requestModel.Request;
//get the Response
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(result);
// process the response...
ResponseModel responseModel = new ResponseModel(request, response, requestModel.UrlModel.AddressID);
_facade.SaveUrlResponse(responseModel);
}
private void ScanTimeoutCallback(object requestModel, bool timedOut)
{
if (timedOut)
{
RequestModel reqState = (RequestModel)requestModel;
if (reqState != null)
reqState.Request.Abort();
}
if (_x == _url_List.Count)
{
resetTimer();
}
}
protected override void OnStop()
{
// TODO: Add code here to perform any tear-down necessary to stop your service.
}
}
}
Okay, I think I am getting somewhere. I have moved my code to a console app. I am able to get the results saved to the database by using either GetResponse (sync) and BeginGetResponse (async). From what I can tell I believe this is a good solution. Can somebody verify this and let me know if you foresee any problems once this is moved to a Windows Service. Here is the new code
using System;
using System.Collections.Generic;
using System.Net;
using System.Threading;
namespace ConsoleApplication2
{
static class Program
{
private static List<UrlModel> _url_List = null;
private static Object _acctLock = new object();
private static Facade _facade = new Facade();
static void Main(string[] args)
{
_url_List = new List<UrlModel>
{
new UrlModel(address: "http://www.microsoft.com", addressID: 1),
new UrlModel(address: "http://www.google.com", addressID: 2),
new UrlModel(address: "http://www.stackoverflow.com", addressID: 3)
};
lockThreadAndGetUrlStatus(_url_List);
Console.ReadLine();
}
static void lockThreadAndGetUrlStatus(List<UrlModel> _url_List)
{
Thread[] threads;
try
{
threads = new Thread[_url_List.Count];
Thread.CurrentThread.Name = "main";
int i = 0;
foreach (UrlModel url in _url_List)
{
//Thread t = new Thread(() => scanSites(url));
Thread t = new Thread(() => scanSitesWithAsync(url));
t.Name = i.ToString();
threads[i] = t;
i += 1;
}
for (i = 0; i < _url_List.Count; i++)
{
Console.WriteLine("Thread {0} Alive : {1}", threads[i].Name, threads[i].IsAlive);
threads[i].Start();
Console.WriteLine("Thread {0} Alive : {1}", threads[i].Name, threads[i].IsAlive);
}
Console.WriteLine("Current Priority : {0}", Thread.CurrentThread.Priority);
Console.WriteLine("Thread {0} Ending", Thread.CurrentThread.Name);
}
catch (Exception ex)
{
throw ex;
}
}
static void scanSitesWithAsync(UrlModel url)
{
try
{
lock (_acctLock)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url.Address);
request.Method = "HEAD";
RequestModel requestModel = new RequestModel(request, url);
IAsyncResult result = request.BeginGetResponse(new AsyncCallback(saveUrlResponseWithAsync), requestModel);
ThreadPool.RegisterWaitForSingleObject
(
result.AsyncWaitHandle,
new WaitOrTimerCallback(scanTimeoutCallback),
requestModel, 30000, true
);
}
}
catch (Exception ex)
{
throw ex;
}
}
static void saveUrlResponseWithAsync(IAsyncResult result)
{
try
{
RequestModel requestModel = (RequestModel)result.AsyncState;
HttpWebRequest request = (HttpWebRequest)requestModel.Request;
//get the Response
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(result);
// process the response...
ResponseModel responseModel = new ResponseModel(requestModel.Request, response, requestModel.UrlModel.AddressID);
_facade.SaveUrlResponse(responseModel);
Console.WriteLine(response.StatusCode);
}
catch (Exception ex)
{
throw ex;
}
}
static void scanTimeoutCallback(object requestModel, bool timedOut)
{
try
{
if (timedOut)
{
RequestModel reqState = (RequestModel)requestModel;
if (reqState != null)
reqState.Request.Abort();
}
}
catch (Exception ex)
{
throw ex;
}
}
}
}
looks like you are trying to issue 3 async requests at the same time. By default, the HTTP/1.1 protocol only specifies 2 connections
I have a property that RaisePropertyChanged(PropName, oldValue, true, true) when I don't have any connection to the internet no more but it throws the exception that I'm on the wrong thread.
So I want to update the property form my ViewModel but how do I get the current thread in my ViewModel or what is you proposal for a solution?
My ViewModel-ctor
public MyViewModel()
{
// START LISTENING TO NETWORKSTATUS
NetworkInformation.NetworkStatusChanged += OnNetworkStatusChangedHandler;
}
NetworkChanged-callback method
private async void OnNetworkStatusChangedHandler(object sender)
{
ConnectionProfile profile = NetworkInformation.GetInternetConnectionProfile();
if (profile == null)
{
IsRefreshEnabled = false;
}
else
{
IsRefreshEnabled = true;
}
}
My Property
public const string IsRefreshEnabledPropertyName = "IsRefreshEnabled";
private bool _isRefreshEnabled = true;
public bool IsRefreshEnabled
{
get { return _isRefreshEnabled; }
set
{
if (_isRefreshEnabled == value) { return; }
var oldValue = _isRefreshEnabled;
_isRefreshEnabled = value;
RaisePropertyChanged(IsRefreshEnabledPropertyName, oldValue, value, true);
}
}
Thanks in advance!
You need to replace the RaisePropertyChanged call to:
await Dispatcher.RunAsync(DispatcherPriority.Normal, (){RaisePropertyChanged(IsRefreshEnabledPropertyName, oldValue, value, true)});
That will cause the call to RaisePropertyChanged to run on the UI thread.
I'm assuming that your class derives from a Xaml control (to access the Dispatcher property on the control).