I'm trying to create an IObservable from the following event:
public delegate bool Handle<in T>(T obj, Foo foo);
event Handle<Bar> Finance;
Any suggestions on how to properly create the observable?
Note, neither Foo nor Bar is based on EventArgs
Thanks!
You can try something like:
public class Test
{
public delegate void Handle<in T>(T obj, Foo foo);
public event Handle<Bar> Finance;
}
public static class TestEx
{
static IObservable<Tuple<Bar, Foo>> WhenFinanceChanged(this Test t)
{
return Observable.Create<Tuple<Bar, Foo>>(observer =>
{
Test.Handle<Bar> handler = (obj, foo) => observer.OnNext(Tuple.Create<Bar, Foo>(obj, foo));
t.Finance += handler;
return Disposable.Create(() => t.Finance -= handler);
});
}
}
Related
Is there way to overriding method in Dart like JAVA, for example:
public class A {
public void handleLoad() {
}
}
And when overriding:
A a = new A() {
#Override
public void handleLoad() {
// do some code
}
};
No, Dart does not have anonymous classes. You have to create a class that extends A and instantiate it.
No but it much less useful in Dart because you can just reassign function:
typedef void PrintMsg(msg);
class Printer {
PrintMsg foo = (m) => print(m);
}
main() {
Printer p = new Printer()
..foo('Hello') // Hello
..foo = ((String msg) => print(msg.toUpperCase()))
..foo('Hello'); //HELLO
}
However you will need some extra boilerplate to access instance.
Use type Function:
class A {
final Function h
A(this.h);
void handleLoad(String loadResult) { h(loadResult); }
}
Or
class A {
final Function handleLoad;
A(this.handleLoad);
}
A a = new A((String loadResult){
//do smth.
});
I'm using Trial Ultimate version of PostSharp 4.0 but this doesn't work for me. Can you please check my code and advise. The error doesn't gets logged. And if i put the breakpoint doesn't hit onException method
This is code that I've written for Error handling Aspect
[Serializable]
public class MyMethodAspectAttribute : OnMethodBoundaryAspect
{
public MyMethodAspectAttribute()
{
this.ApplyToStateMachine = true;
}
public override void OnEntry(MethodExecutionArgs args)
{
Console.Write("Method Entry");
}
public override void OnException(MethodExecutionArgs args)
{
Console.Write(args.Exception.Message);
args.ReturnValue = null;
args.FlowBehavior = FlowBehavior.Return;
}
}
This is class where I've implemented this aspect
public class ErrorMethods
{
[MyMethodAspect]
public Task<int> Calculate(int i, int j)
{
var task = Task.Factory.StartNew(
() => i / j);
return task;
}
}
This is how I've used this method
private async void Button_Click(object sender, RoutedEventArgs e)
{
var obj = new ErrorMethods();
var result = await obj.Calculate(1, 0);
if (null == result)
{
MessageBox.Show("error");
}
}
The Calculate method in your example is not an async method, so setting ApplyToStateMachine aspect's property doesn't have effect on this method. The exception is thrown when a newly created task executes in the background and the aspect has no chance of catching it.
If you change your Calculate method to async method, then the async state machine execution can be intercepted by the aspect and OnException handler is invoked upon exception.
Note, however that setting the ReturnValue and FlowBehavior does not alter the flow of the state machine, so the exception will not be swallowed.
public class ErrorMethods
{
[MyMethodAspect]
public async Task<int> Calculate( int i, int j )
{
return await Task.Factory.StartNew( () => i / j );
}
}
I have two classes. First is using for store boolean value from ToggleSwitchButton by using IsolatedStorage.
Like this...
private void tglSwitch_Checked(object sender, RoutedEventArgs e)
{
System.IO.IsolatedStorage.IsolatedStorageSettings.ApplicationSettings["EnableLocation"] = true;
}
private void tglSwitch_Unchecked(object sender, RoutedEventArgs e)
{
System.IO.IsolatedStorage.IsolatedStorageSettings.ApplicationSettings["EnableLocation"] = false;
}
The second class will use the boolean value from the first class to do something.
Like this...
if(booleanValFromFirst){
//Do something
}
else{
//Do something
}
Thanks.
Is this, what you want?
if ((bool)System.IO.IsolatedStorage.IsolatedStorageSettings.ApplicationSettings["EnableLocation"] == true)
P.S. I would recommend for you to create a single class for all values, stored in Application Settings and work with it.
Like this:
public static class SettingsManager
{
private static IsolatedStorageSettings appSettings;
public static IsolatedStorageSettings AppSettings
{
get { return SettingsManager.appSettings; }
set { SettingsManager.appSettings = value; }
}
public static void LoadSettings()
{
// Constructor
if (appSettings == null)
appSettings = IsolatedStorageSettings.ApplicationSettings;
// Generate Keys if not created
if (!appSettings.Contains(Constants.SomeKey))
appSettings[Constants.SomeKey] = "Some Default value";
// generate other keys
}
}
Then you can work with that class instance
Initialize it at your startup class as SettingsManager.LoadSettings();
an then in any class just call for it:
if ((bool)SettingsManager.AppSettings[Constants.SomeBoolKey])
doSomething();
I am wondering if it is possible to use Reactive Extensions in Word. I have seen this where Jeff shows how to wire up a workbook open event in excel http://social.msdn.microsoft.com/Forums/en/rx/thread/5ace45b1-778b-4ddd-b2ab-d5c8a1659f5f.
I wondering if I could do the same sort of thing in word.
I have got this far....
public static class ApplicationExtensions
{
public static IObservable<Word.Document> DocumentBeforeSaveAsObservable(this Word.Application application)
{
return Observable.Create<Word.Document>(observer =>
{
Word.ApplicationEvents4_DocumentBeforeSaveEventHandler handler = observer.OnNext;
application.DocumentBeforeSave += handler;
return () => application.DocumentBeforeSave -= handler;
});
}
}
but I receive the error No overload for 'OnNext' matches delegate 'Microsoft.Office.Interop.Word.ApplicationEvents4_DocumentBeforeSaveEventHandler
Can anyone point me in the right direction.
Regards
Mike
Your problem is an issue of delegate signatures.
IObserver<T>.OnNext is defined as void (T value)
whereas ApplicationEvents4_DocumentBeforeSaveEventHandler is defined as void (Document doc, ref bool SaveAsUI, ref bool Cancel)
If you only need to emit the Document (and not the other details, like making it cancelable), you can do something like this:
public static IObservable<Word.Document> DocumentBeforeSaveAsObservable(
this Word.Application application)
{
return Observable.Create<Word.Document>(observer =>
{
Word.ApplicationEvents4_DocumentBeforeSaveEventHandler handler =
(doc, ref saveAsUI, ref cancel) => observer.OnNext(doc);
application.DocumentBeforeSave += handler;
return () => application.DocumentBeforeSave -= handler;
});
}
If you do require all the data, you'll need to create a wrapper class of some kind an IObservable sequence can only emit a single type:
public class DocumentBeforeSaveEventArgs : CancelEventArgs
{
public Document Document { get; private set; }
public bool SaveAsUI { get; private set; }
public DocumentBeforeSaveEventArgs(Document document, bool saveAsUI)
{
this.Document = document;
this.SaveAsUI = saveAsUI;
}
}
And then you can use it like so:
public static IObservable<Word.Document> DocumentBeforeSaveAsObservable(
this Word.Application application)
{
return Observable.Create<Word.Document>(observer =>
{
Word.ApplicationEvents4_DocumentBeforeSaveEventHandler handler =
(doc, ref saveAsUI, ref cancel) =>
{
var args = new DocumentBeforeSaveEventArgs(doc, saveAsUI);
observer.OnNext(args);
cancel = args.Cancel;
};
application.DocumentBeforeSave += handler;
return () => application.DocumentBeforeSave -= handler;
});
}
I'm considering re-rewriting some of my MVC controllers to be async controllers. I have working unit tests for these controllers, but I'm trying to understand how to maintain them in an async controller environment.
For example, currently I have an action like this:
public ContentResult Transaction()
{
do stuff...
return Content("result");
}
and my unit test basically looks like:
var result = controller.Transaction();
Assert.AreEqual("result", result.Content);
Ok, that's easy enough.
But when your controller changes to look like this:
public void TransactionAsync()
{
do stuff...
AsyncManager.Parameters["result"] = "result";
}
public ContentResult TransactionCompleted(string result)
{
return Content(result);
}
How do you suppose your unit tests should be built? You can of course invoke the async initiator method in your test method, but how do you get at the return value?
I haven't seen anything about this on Google...
Thanks for any ideas.
As with any async code, unit testing needs to be aware of thread signalling. .NET includes a type called AutoResetEvent which can block the test thread until an async operation has been completed:
public class MyAsyncController : Controller
{
public void TransactionAsync()
{
AsyncManager.Parameters["result"] = "result";
}
public ContentResult TransactionCompleted(string result)
{
return Content(result);
}
}
[TestFixture]
public class MyAsyncControllerTests
{
#region Fields
private AutoResetEvent trigger;
private MyAsyncController controller;
#endregion
#region Tests
[Test]
public void TestTransactionAsync()
{
controller = new MyAsyncController();
trigger = new AutoResetEvent(false);
// When the async manager has finished processing an async operation, trigger our AutoResetEvent to proceed.
controller.AsyncManager.Finished += (sender, ev) => trigger.Set();
controller.TransactionAsync();
trigger.WaitOne()
// Continue with asserts
}
#endregion
}
Hope that helps :)
I've written short AsyncController extension method that simplifies unit testing a bit.
static class AsyncControllerExtensions
{
public static void ExecuteAsync(this AsyncController asyncController, Action actionAsync, Action actionCompleted)
{
var trigger = new AutoResetEvent(false);
asyncController.AsyncManager.Finished += (sender, ev) =>
{
actionCompleted();
trigger.Set();
};
actionAsync();
trigger.WaitOne();
}
}
That way we can simply hide threading 'noise':
public class SampleAsyncController : AsyncController
{
public void SquareOfAsync(int number)
{
AsyncManager.OutstandingOperations.Increment();
// here goes asynchronous operation
new Thread(() =>
{
Thread.Sleep(100);
// do some async long operation like ...
// calculate square number
AsyncManager.Parameters["result"] = number * number;
// decrementing OutstandingOperations to value 0
// will execute Finished EventHandler on AsyncManager
AsyncManager.OutstandingOperations.Decrement();
}).Start();
}
public JsonResult SquareOfCompleted(int result)
{
return Json(result);
}
}
[TestFixture]
public class SampleAsyncControllerTests
{
[Test]
public void When_calling_square_of_it_should_return_square_number_of_input()
{
var controller = new SampleAsyncController();
var result = new JsonResult();
const int number = 5;
controller.ExecuteAsync(() => controller.SquareOfAsync(number),
() => result = controller.SquareOfCompleted((int)controller.AsyncManager.Parameters["result"]));
Assert.AreEqual((int)(result.Data), number * number);
}
}
If you want to know more I've written a blog post about how to Unit test ASP.NET MVC 3 asynchronous controllers using Machine.Specifications
Or if you want to check this code it's on a github