Develop Reference

How to solve Deployment Error in Xamarin Forms?

I have just updated Visual Studio 2017 and create one new project. It build successfully but giving deployment error. Application doesn't deploy on my Samsung J7 device. Before the update, it was working fine.
How to resolve this?

there are four solutions:
-read this post
-This bug is in last version Visual Studio 15.6. If you use this version make downgrade to 15.5.
How delete current version
Download older version - select your version on this page.
-Or wait for the next update
-or disable the signing of the apk in the properties of your project.
Edit your csproj and set :
<AndroidKeyStore>false</AndroidKeyStore>
But in this case you will not be able to publish your package in Google Play.

download the used SDK. Update your visual Studio(if u r not using the latest one). Check Paths. Restart Visual Studio after that. it will run

About 15.6.1, I suggest you uninstall all of your Android SDK, and reinstall, it works for me!
Also you can refer to this.

Unable to setup Android Studio 3.0.1

I installed Android Studio 3.0.1 and everything seemed to go as expected. When first starting up, I got to the point of downloading the SDK components, and received the following error.
"Android Support Repository, Android SDK Tools and 7 more SDK components were not installed"
Has anybody every seen this? Any ideas or suggestions are greatly appreciated.
I am using Windows 10 64 bit. I was able to capture some more details of the failure.
"java.nio.file.AccessDeniedException: C:\Users\gcleveland\Documents\Android\SDK2\extras\android\m2‌​repository.backup.i‌​nstaller.installDat‌​a -> C:\Users\gcleveland\Documents\Android\SDK2\extras\android\m2‌​repository.installe‌​r.installData Warning: Failed to move original content of C:\Users\gcleveland\Documents\Android\SDK2\extras\android\m2‌​repository back into place! It should be available at C:\Users\gcleveland\Documents\Android\SDK2\extras\android\m2‌​repository.backup"
There are multiple other instances like this but different directories.
It is almost as if my permissions are not correct. I have full administrative rights and run android studio as an administrator.

I ran into similar issues with the exe file version and resolved them by instead downloading and installing the zip version of Android Studio 3.0.1 for Windows 10 (https://dl.google.com/dl/android/studio/ide-zips/3.0.1.0/android-studio-ide-171.4443003-windows.zip). After unzipping this file, I simply executed its bin/studio64.exe. I also switched my networking connection to NOT need a proxy, which may also have helped to resolve the issue.

Android Studio freezes after updating to 2.0

I have just updated my Android Studio from 1.4 to 2.0, on startup it freezes on splash-screen. is it possible to fix it or i have to download it again?

Its very strange. I have also updated to 2.0 in my MAC, Ubuntu and Windows 10. I didn't feel any issues till now in any of these.
Please note that 2.0 is still a preview. You may have to wait till Google releases the stable version.

Which operating system are you using?
For Windows, check the log of
C:\Users\<Username>\.AndroidStudioPreview2.0\system\log\idea.log
and paste here the last relevant entries on the bottom with a recent timestamp, containing an error message or indication of a possible freeze.
Also, check that you don't have any Android Studio, IntelliJ, or java-processes running before you start Android Studio.

This is an answer for my question, after trying many methods now it works fine.
This is how i resolved my problem by:
Updating Android SDK Tools and the latest SDK Platform
Removing the Android Studio cache folder situated in
C:\Users\<username>\.AndroidStudioPreview2.0
Running android studio again

At First Update Your Android SDK Tools (Support Repository )
Actually Android Studio creates a local directory . AndroidStudio to
cache its own data. In most environments, this is acceptable. However,
the size of the directory can easily exceed 300Mb and, if you have a
space constraint on your home drive (or a roaming profile in windows),
this may be better off in some other place.
The location of this directory is placed in an idea.properties file in the bin/ directory of your AS is installed.

Xamarin MonoDroid does not support running the previous version

I have just installed the Xamarin tools, installation went without any errors.
I have launched VS 2013 Update 4 Pro and created Blank App ( Native Shared ).
I did not modify code or project structure, just tried to run.
So i have changed the Startup Project to Adnroid project:
Then i have rebuilt the entire solution.
The console prompted Rebuild succeeded.
I have noticed that debugging button has a very long path, which is strange:
If i click on any option it opens the AVD Manager, but doesn't change the Start, to selected device.
So i have tried launching the Emulator from AVD manager and it works.
But when i click start in VS it prompts me:
Where is the problem? How can a newly installed app not work?

You project is most likely targeting lower version of android API. Try changing the target android version.

A note here should be that within Visual Studio/Xamarin the settings regarding supported version are within the solution settings of that project.
In this way you can change the version to support what you need, or if it is correct download a more current simulator.
This can be done with GenyMotion for instance or Xamarin Android Player.

This error message currently can be shown due to a large number of different issues.
Visit Build Failed. MonoDroid does not support running the previous version to learn about the different causes for this error message.

Eclipse: won't let me use Android SDK, wrongly claims my ADT is out of date

I'm developing for Android with Eclipse, and all was working well until yesterday. I used Ninite to update all my stuff, including JREs and everything (pro tip: do not do that), and it restarted my computer without asking in the middle of editing my workspace.
This caused all kinds of filthy problems, but now it all works, except for Android. I've updated Android SDK and the eclipse ADT, then when I try to tell Eclipse the SDK location, it gives this error:
This Android SDK requires Android Developer Toolkit version 14.0.0 or
above. Current version is 12.0.0.v201106281929-138431. Please update
ADT to the latest version.
Now, this is an outright lie. My ADT is version 14.0.something. I've tried Help>Check for updates, it says there are no updates. I've tried Help>Install new software...>Available Software Sites and removing the ADT repo, then reinstalling ADT, and it says it failed because I already have version 14.0.whatever.
How do I convince eclipse that my ADT is up to date??

I found the answer to the problem. (I'm using Helios, but it should work anyway)
Goto folder /Program Files(x86)/Eclipse/Plugins/ and make sure previous older versions of com.android.ide.eclipse.adt.package_##... are deleted (sometimes update fails to delete because of UAC). Keep the current desired version and complete the following.
Run Eclipse as administrator or disable UAC temporarily. (windows 7)
Go to Help → Install New Software.
On Work with: type https://dl-ssl.google.com/android/eclipse/ and press ENTER.
Wait for Eclipse to fetch the repository. An item named Developer tools will appear in the list.
Mark it for install, press Next and follow the steps to install the ADT tools.
When finished, it will ask to restart Eclipse. Make sure you do this.
When Eclipse restarts, all your Android SDK packages should show up again.
Dont forget to resume UAC if you need it.

An option is to manually download the ADT plugin (ADT archive) required. The page is, http://developer.android.com/sdk/eclipse-adt.html. The page reveals ADT 18 is available at http://dl.google.com/android/ADT-18.0.0.zip. The link is closer to the bottom page. I needed 17 although 18 was the latest, so I modified the download URL, changing 18 to 17.
Select Help → Install New Software → Add → Choose Archive and select the location of the downloaded ADT archieve file, Choose OK.
Select the components required and proceed as required. You may get a message that the software is already installed, proceed with the installation.
Hope this helps.

I had the same problem. My ADT in the eclipse was 8.x version. But my app required version 12 or more. So, I decided to upgrade both the Android SDK and ADT to the latest (at this time latest ADT is 17). I was able to upgrade the SDK but not the ADT. It always complained I got the versions already but I only had 8.x. The new SDK that I just upgraded would function only with ADT 14 and above. So, I had successfully broken my android development!!
The reason why I wasn't able to upgrade my ADT to the latest was because I was using Eclipse 3.5. The newer ADT versions require 3.6 or above. This small but key bit of information was really at the bottom of the error generated by Eclipse which required scrolling down (since only the top few lines of error were displayed). You typically wouldn't scroll down since these top few lines were followed by whitespace lines :). I did not scroll and I guess I wasted about a day trying to rectify this problem. But eventually I saw those 2 up/down arrows at the right of the dialog box and I scrolled down. There it clearly mentioned ADT 17 requires Eclipse runtime 3.6 and over.
So my solution was to find a suitable ADT that would work with Eclipse 3.5. Yes, tomorrow when I am in the mood, I shall upgrade to Eclipse 3.6 or 3.7 and the boat load of plugins I have :)

I've just upgraded my Android SDK version, and had exactly the same issue.
The 'Check For updates' Eclipse command failed because, for some reasons, Android Traceview failed to update.
My solution was to :
* Open Eclipse → Help → About Eclipse .
* Click Installation Details.
* Here select all the android related lines, and update them one by one, restarting eclipse each time.
And finally it worked ( even with Helios ) !

Best option is go to open eclipse ID
Then go to Help → About Eclipse >>
u will find the Installation Details button click on that
And now u can see the all anriod extension installed.
Select all or select one by one and just click the update button.
you will get the latest version from the net.
Hope these will help you all.

In Eclipse:
Help → Check for Updates.

Your ADT and SDK is not up-to-date yet and Eclipse is complaining about the right stuff...
Open Android SDK Manager from toolbar and update your SDK from there. It doesn't help if you are checking Eclipse updates. Because through Eclipse you cannot check SDK updates for Android.
Button looks like this :

I'm hearing a common issue is that newer Android ADK versions require newer eclipse versions. Colleagues who hit this say they installed Indigo in place of older Helios versions and were able to resolve the issue this way. I have not yet done the same myself.

To anyone else with this problem, my solution was just to delete the Eclipse folder, and download a new copy from scratch. I had to then re-download all plugins including adt, which worked this time round.