Create winform project targeting .net 4.5.1
Install-Package PropertyChanged.Fody
[ImplementPropertyChanged]
public class PersonFody
{
public string Name { get; set; }
}
PersonFody _fod = new PersonFody();
_fod. //Name is the only property and no events to subscribe
Is it possible to subscribe to a PropertyChanged event at design time using fody?
I guess this is late, but yes you can. Just add this event to your class:
public event PropertyChangedEventHandler PropertyChanged;
Fody will recognize you have the correct event for the IPropertyChanged interface and wire all your properties to trigger that event.
Related
I am maintaining a legacy Cloud Services application hosted on Azure targeting .net 4.6.1. Inside the Application_Start method of the Global.asax on the Web Role we are registering an event handler for RoleEnvironment.StatusCheck however our logs are demonstrating that this event call back is never being called or triggered.
According to this blog: https://convective.wordpress.com/2010/03/18/service-runtime-in-windows-azure/ we were expecting this event to be triggered every 15 seconds and we believe this was happening however has since stopped. We expect that the stopped working around the time we installed some new DLLs into the solution (some of these dlls include: Microsoft.Rest.ClientRuntime.dll, Microsoft.Azure.Storage.Common.dll, Microsoft.Azure.Storage.Blob.dll, Microsoft.Azure.KeyVault.dll)
We've tried RDP-ing onto the VM to check the event logs but nothing obvious is there. Any suggestions on where we may be able to search for clues?
It seems your event handler is not registered. Try below code with a different approach:
public class WorkerRole : RoleEntryPoint
{
public override bool OnStart()
{
RoleEnvironment.StatusCheck += RoleEnvironmentStatusCheck;
return base.OnStart();
}
// Use the busy object to indicate that the status of the role instance must be Busy
private volatile bool busy = true;
private void RoleEnvironmentStatusCheck(object sender, RoleInstanceStatusCheckEventArgs e)
{
if (this.busy)
{
// Sets the status of the role instance to Busy for a short interval.
// If you want the role instance to remain busy, add code to
// continue to call the SetBusy method
e.SetBusy();
}
}
public override void Run()
{
Trace.TraceInformation("Worker entry point called", "Information");
while (true)
{
Thread.Sleep(10000);
}
}
public override void OnStop()
{
base.OnStop();
}
}
With AspNetCore.SignalR (1.0.0 preview1-final) and AspNetCore.All (2.0.6), how can I invoke a method on a hub in server code that is not directly in a Controller and is in a class that cannot be made via Dependency Injection?
Most examples assume the server code is in a Controller and should 'ask' for the hub via an injectable parameter in a class that will created by DI.
I want to be able to call the hub's method from server code at any time, in code that is not injected. The old SignalR had a GlobalHost that enabled this approach. Basically, I need the hub to be a global singleton.
Now, everything seems to be dependent on using Dependency Injection, which is introducing a dependency that I don't want!
I've seen this request voiced in a number of places, but haven't found a working solution.
Edit
To be more clear, all I need is to be able to later access the hubs that I've registered in the Configure routine of the Startup class:
app.UseSignalR(routes =>
{
routes.MapHub<PublicHubCore>("/public");
routes.MapHub<AnalyzeHubCore>("/analyze");
routes.MapHub<ImportHubCore>("/import");
routes.MapHub<MainHubCore>("/main");
routes.MapHub<FrontDeskHubCore>("/frontdesk");
routes.MapHub<RollCallHubCore>("/rollcall");
// etc.
// etc.
});
If I register them like this:
services.AddSingleton<IPublicHub, PublicHubCore>();
it doesn't work, since I get back an uninitiated Hub.
No It's not possible. See "official" answer from david fowler https://github.com/aspnet/SignalR/issues/1831#issuecomment-378285819
How to inject your hubContext:
Best solution is to inject your hubcontext like IHubContext<TheHubWhichYouNeedThere> hubcontext
into the constructor.
See for more details:
Call SignalR Core Hub method from Controller
Thanks to those who helped with this. Here's what I've ended up on for now...
In my project, I can call something like this from anywhere:
Startup.GetService<IMyHubHelper>().SendOutAlert(2);
To make this work, I have these extra lines in Startup.cs to give me easy access to the dependency injection service provider (unrelated to SignalR):
public static IServiceProvider ServiceProvider { get; private set; }
public static T GetService<T>() { return ServiceProvider.GetRequiredService<T>(); }
public void Configure(IServiceProvider serviceProvider){
ServiceProvider = serviceProvider;
}
The normal SignalR setup calls for:
public void Configure(IApplicationBuilder app){
// merge with existing Configure routine
app.UseSignalR(routes =>
{
routes.MapHub<MyHub>("/myHub");
});
}
I don't want all my code to have to invoke the raw SignalR methods directly so I make a helper class for each. I register that helper in the DI container:
public void ConfigureServices(IServiceCollection services){
services.AddSingleton<IMyHubHelper, MyHubHelper>();
}
Here's how I made the MyHub set of classes:
using Microsoft.AspNetCore.SignalR;
using System.Threading.Tasks;
public class MyHub : Hub { }
public interface IMyHubHelper
{
void SendOutAlert(int alertNumber);
}
public class MyHubHelper : IMyHubHelper
{
public IHubContext<MyHub> HubContext { get; }
public MyHubHelper(IHubContext<MyHub> hubContext)
{
HubContext = hubContext;
}
public void SendOutAlert(int alertNumber)
{
// do anything you want to do here, this is just an example
var msg = Startup.GetService<IAlertGenerator>(alertNumber)
HubContext.Clients.All.SendAsync("serverAlert", alertNumber, msg);
}
}
This is a nice solution. In .NET Core 2.1 the service provider is disposed and you get cannot access disposed object. The fix is to create a scope:
public void Configure(IApplicationBuilder app, IHostingEnvironment env, IServiceProvider serviceProvider)
{
ServiceProvider = serviceProvider.CreateScope().ServiceProvider;
I would like to control events of Load Families and Create Type with revit api. Someone can give me a direction ? I don't understand very well the documentation that I read.
First you need to subscribe to an event by creating an event listener in the IExternalApplication OnStartup method.
public class AppCommand : IExternalApplication
{
public Result OnStartup(UIControlledApplication application)
{
application.ControlledApplication.FamilyLoadedIntoDocument += OnFamilyLoaded;
return Result.Succeeded;
}
}
Next you need a handler for that event:
private void OnFamilyLoaded(object sender, FamilyLoadedIntoDocumentEventArgs args)
{
// do work here
}
When finished you need to unregister the event handler:
public Result OnShutdown(UIControlledApplication application)
{
application.FamilyLoadedIntoDocument -= OnFamilyLoaded;
return Result.Succeeded;
}
The other events available that you can subscribe to are these:
http://www.revitapidocs.com/2018/b69e9d33-3c49-e895-3267-7daabab85fdf.htm
Cheers!
I'm using Windows Azure Mobile Services to store and retrieve data in my Windows Phone 8 app. This is a bit of a complicated issue so I will do my best to explain it.
Firstly I'm using raw push notifications to receive a message and when it receives the message it updates a listbox in my app. When I open my app, navigate to the page with the ListBox and receive a push notification the ListBox updates fine. If I press back, then navigate to the same page with the ListBox, the push notification is received, the code to update the ListBox executes with no errors yet the ListBox doesn't update. I have checked that the same code runs using the OnNavigatedTo handler in both scenarios, but it seems like the ListBox does not bind correctly in the second instance when I press back and then re-navigate to the same page. Here are some code snippets:
MobileServiceCollection declarations:
public class TodoItem
{
public int Id { get; set; }
[JsonProperty(PropertyName = "text")]
public string Text { get; set; }
}
private MobileServiceCollection<ToDoItem, ToDoItem> TodoItems;
private IMobileServiceTable<TodoItem> todoTable = App.MobileService.GetTable<TodoItem>();
Push Notification Received Handler:
void PushChannel_HttpNotificationReceived(object sender, HttpNotificationEventArgs e)
{
string message;
using (System.IO.StreamReader reader = new System.IO.StreamReader(e.Notification.Body))
{
message = reader.ReadToEnd();
}
Dispatcher.BeginInvoke(() =>
{
var todoItem = new TodoItem
{
Text = message,
};
ToDoItems.Add(todoItem);
}
);
}
I have tried using:
ListItems.UpdateLayout();
and
ListItems.ItemsSource = null;
ListItems.ItemsSource = ToDoItems;
before and after the code in the above procedure that adds the ToDoItem but it didn't help.
The following procedure is called in my OnNavigatedTo event handler, and refreshes the Listbox and assigns ToDoItems as the items source:
private async void RefreshTodoItems()
{
try
{
ToDoItems = await todoTable
.ToCollectionAsync();
}
catch (MobileServiceInvalidOperationException e)
{
MessageBox.Show(e.Message, "Error loading items", MessageBoxButton.OK);
}
ListItems.ItemsSource = ToDoItems;
}
The above procedure is async but I have made sure it completes before receiving any notifications. Even so, as mentioned above when I open the app, navigate to the page that shows the ListBox it updates fine. When I press back, navigate to the same page again, it doesn't work. When I back out of the app, re-open it, navigate to the page with the ListBox, it works again, and then fails if I press back and re-open the page. So it seems the ListBox is not binding to ToDoItems correctly when I press back and navigate to the same page.
Any help appreciated. Thanks.
Can you modify your approach a bit to use Data Binding and the MVVM model to bind your model to your view.
It might look like a bit of effort initially but will save you a lot of debugging hours later on.
Just follow the below steps
Create a new class that implements INotifyPropertyChanged
Add the below method implementation
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (null != handler)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
Add public ObservableCollection<TodoItem> TodoItems{ get; private set; } and initialize it in the constructor.
Every PhoneApplicationPage has a DataContext member. Assing it to a singleton instance of the above class that you create.
In the XAML, add the property ItemsSource="{Binding TodoItems}" to the list.
In the DataTemplate of the list use ItemsSource="{Binding Text}" for the control you wish to display this value on. ( e.g. TextBlock )
Now whenever you add elements to the collection, it will be reflected in the UI, and vice-versa.
I have a requirement in JavaFX 2 to display the notifications on the header. These notifications are populated in the database through an external system.
When a new notification is inserted in the database, my JavaFX application should listen to the same and refresh the header.
One solution I can think about is to implement a timeline that triggers the code to retrieve the latest notification status once every fixed time period, may be once every 2 mins.
Other than this, is there any other way to achieve this? Any hints on this would be highly appreciated.
You can create a new Task that would be listening (or checking) for changes in your database. This Task would be running in a different Thread as not to block your UI. Once a change occurs, it can then update your UI.
Your code could look like this :
//... initialize your variables.
task = new DatabaseWatcher();
executor = Executors.newSingleThreadExecutor();
executor.execute(task);
And your DatabaseWatcher :
public class DatabaseWatcher extends Task<Object> {
public DatabaseWatcher() {
//initialize here
}
#Override
protected Object call() throws Exception {
//Get data from database
//if new update :
updateUI();
return null;
}
private void updateUI() {
Platform.runLater(new Runnable() {
#Override
public void run() {
//Set your new values in your UI
//Call the method in your UI to update values.
}
});
}
}
This should get you started on the right path.
See Also
Multiple FXML with Controllers, share object, more specifically this answer
javafx, update ui from another thread
Concurrency in JavaFX