How to debug app when it's killed

Question

My app has a bug on certain activities: when it restarts (when it's killed and then opened again with multitasker), it crashes. I assume it has something to do with my singleton, but I'm not sure. I'd like to pinpoint the problem, but I can't debug since the debugger stops when I kill the application (I'm using adb shell am kill <package-name>).

Does anyone know how I can debug this problem? (Or give me a hint what my problem might be for that matter)

Answer 1

You can add the following code to the onCreate() method of your main activity:

android.os.Debug.waitForDebugger();

This will pause your app till a debugger is attached to the process.

Then :

• Run your app
• Put your app in background (say, with the home button)
• Kill the process or use an app like MemoryPump to fill the RAM and have your app killed by Android
• Switch back to your app with the multitask pan (the app will start and wait for the debugger)
• Attach your android studio debugger to you app (icon in the Android Studio toolbar somewhere between the 'run app' icon and the 'stop application' icon)
• Debug your app

Answer 2

I would use DDMS (Dalvik Debug Monitor Server (DDMS) to capture the stack trace, etc.. after your kill and restart our app.

(FYI: It is already installed along with the rest of the Android toolset)

While it is not going to allow you to debug you app via VS/XS, it can help you pin the area of your app that is the cause. From there I would add logging around the trouble area (i.e. the old-fashion printf style debugging)

http://developer.android.com/tools/debugging/ddms.html

To launch from Visual Studio:

From Xamarin Studio: