Develop Reference

Xamarin no longer debugging my app

I've been working on a Xamarin project for a few days and have been testing it fine, but today it has suddenly stopped allowing me to debug the app, either via Live Player, or by connecting my smart phone via USB.
The only error I am getting, as far as I can see, is
Failed to debug your app
I've not got a way of testing it on iOS devices, but the built-in Windows Phone emulator runs the app fine, albeit with an error in my code popping up now and then.
What could be causing the Android version to stop debugging, or how do I at least fix it?

There are a couple of steps that can help with that issue:
Clean the solution and exit visual studio
manually delete the .vs folder in your solution directory
Delete the /obj and /bin folders in your shared code, and in each project for the platforms you are using
if you are developing for iOS, sometimes it helps to restart your mac
Start Visual Studio
Rebuild your shared code project
Rebuild every native project
Beyond that also make sure that you are using the latest versions of Visual Studio, Xamarin and Xamarin.Forms on all your computers, and that the nuGet Packages your project is using are at the very same version each in shared and native code
Also check, if your app isn't throwing an unexpected exception during its initialization. Especially if not caught, it can happen that your app crashes before your code gets executed at all.
In addition you may find further information about what is going on at Help -> Xamarin -> Open logs or in the device management in XCode (iOS only)

Try this :
Close visual studio if open.
Open App Data and then go to
(a) Local\Xamarin
(B) Local\Xamarin\Xamarin.Android
Empty these folders.
Open your project and then try to build your application.

Not a proper solution, but I uninstalled and reinstalled Visual Studio. This seems to have fixed the problem, but I've still no idea why it stopped working in the first place.

Black screen after updating to Android Studio 2.2.1

After updating my Android Studio to version 2.2.1 I can't get my app to display anything except black on the screen of my phone. Before updating it used to work. The app uses OpenGL ES 2.0. It works on an emulator but not on the real device. The app is running, it plays sounds as I touch on the screen, it's just not displaying anything. My phone is Huawei Honor 7.
I've tried everything I can think of such as restarting the phone, deleting the app from the phone, cleaning the project multiple times, manually deleting all the build directories and .iml files, disabling the instant run, building with different gradle versions, testing previous revisions of the app, switching between debug and release builds etc.
What could be causing this?

I still don't know what caused this, but what I did to get it working was that I deleted my previous project from Android Studio and made a completely new project with all the new project files stuff that Android Studio created for me, including CMake stuff that didn't exist before, and then copied all the relevant content to it from the previous project. Took one whole day but now at least it works. A lesson learned: Don't update your Android Studio if you're not prepared to spend some time fixing issues. I wish the Android Studio guys had hard of a concept called backwards compatibility...

Phonegap Build in Dreamweaver CS6 - old project runs in emulator instead of current one

I created four or five little test Android apps in Dreamweaver CS6 using PhoneGap Build. Each time, the current app would run in the emulator. Now, instead of running the project in the current site, the emulator64-arm keeps running a previous project when I click the PhoneGap Build icon on the Android emulator home screen. I have tried deleting all my projects from build.phonegap.com, and deleting all but the most recent project from the local drive. Even so, the emulator runs the old project -- which as far as I know, doesn't even exist anymore, either locally or on build.phonegap.com! Do I need to delete the project from the emulator? If so, how would I do that? Any help will be greatly appreciated, cause I'm stumped!
Mac OS X 10.6.8

Mystery solved. The first few times I installed apps on the emulator, I clicked the PhoneGap Build icon to run them. But later appps installed under different names -- I guess based on info I entered into the config.xml file.
Still would be nice to know how to delete those apps from the emulator. But at least the really mysterious part is explained -- why it ran a different app from the one I just built. I was just clicking on the wrong icon.

trouble debugging and running sample android project

I installed the Android 2.2 SDK (2.2 is the version i have on my smartphone). I've tried running the NotePad sample project as an Android project. Here is what happens: the emulator loads, but when I click on the app, the screen goes blank. There are no errors being thrown. Has anyone else run into this problem? If so, how have you fixed it?

When you press run, the emulator loads AND the application should automatically open and run. Also, make sure there are no errors with the code itself.
If all else fails, try a new/ different SDK and make sure the app has no errors during it's installation into the SDK. Look at the Console and LogCat to make sure that there are no errors the emulator runs.

Android project loading to phone removes previously installed project

I am working with Eclipse and running my apps on my phone(Motorola DROID2 GLOBAL, Android 2.2). Once I install a new project the previous one will disappear. Any ideas? Is this Eclipse problem or the phone?

Is a normal behavior of the Android development enviroment, it remove the application that you're debugging to upload the new one (new version).
It is like when you update an application with the Market, the old one will dissapear.

The problem was related to the operating system. Once I got upgrade pushed on my phone I stopped having this issue. Now it's all works just fine and can see all my apps available.