CODEWITHSUNDEEP
c#windows-phone-7
William Melani
William Melani

Reputation: 4268

App Never launches successfully again after Tombstoning. No exception thrown

I am having problems getting my app to restore/load from start after tombstoning.

It fails at the following line:

ServerCollection collection = AppSettings.GetSetting(AppResources.settings_servercollection) as ServerCollection;

This line is in a function that is called inside Launching and Activated.

The AppSettings class is this class Here:, but I modified it to use a object instead of a <T>.

The debugger does not seem to enter the AppSettings function. It also displays the string i'm expecting to key on (AppResources.settings_servercollection), so I do not think that is the problem either.

Lastly, no exceptions are thrown. I have the entire section in a try, and breakpoints inside UnhandledException and NavigationFailed of the application, but I never seem to arrive at any of them.

Has anyone else experienced this before, or know what the cause might be?

Edit: Just wanted to point out that of course the app works after Cleaning/Rebuilding/Reinstalling etc. Edit: I've been able to isolate it to this:

IsolatedStorageSettings Settings = System.IO.IsolatedStorage.IsolatedStorageSettings.ApplicationSettings;

I found that out by placing it in each the Get/Set functions of AppSettings, and seeing it die directly on that line after entering the function. That said, Any ideas?

Upvotes: 2

Views: 187

Answers (3)

William Melani
William Melani

Reputation: 4268

The serialization turned out to be working Okay. The real problem was that I had some infinite recursion going on in a property that I was saving. 

public Dictionary<string, object> Dictionary
        {
            get
            {
                if (_dictionary == null)
                    _dictionary = new Dictionary<string, object>();
                return _dictionary;
            }
            set
            {
                Dictionary = value;
            }
        }

As you can probably see, that was not going to end well. Too bad there wasn't a "StackOverflowException" or anything like there is in the console C# applications i've written before.

Anyway, thanks for the help.. Hope anyone else who has this problem may find this helpful.

Upvotes: 1

Stuart
Stuart

Reputation: 66882

I've seen problems with apps where IsolatedStorage is in an invalid state

I am guessing that this is the problem with your app

  • as the example code posted in Windows phone 7 config / appSettings? did not originally call Save() on the AppSettings after you Store a value (I've just edited it!)
  • so this leaves IsolatedStorageSettings in an invalid state
  • so the application fails to step past the static initializer of private static IsolatedStorageSettings Settings

To try to fix the problem:

  • uninstall your app - this will clear up you isolated storage
  • add a Save() to the end of your StoreSetting() method
  • run again

Upvotes: 2

Matt Lacey
Matt Lacey

Reputation: 65564

I suspect a problem with serialising (and deserializing) your ServerCollection object.

Internally, objects passed to IsolatedStorageSettings are serialized as XML (using DataContractSerializer - which is probably part of the performance hit of using IsolatedStorageSettings). If your object can't be deserialized correctly you could see this problem.

As an alternative I'd recommend handling the [de]serialization yourself and then storing the serialized version in IsolatedStorageSettings.

Upvotes: 1

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