Develop Reference

com.google.gms.location does not exist

I am trying to add a map on the Xamarin.Android application. So far, I have added only map, I did not add any location listener. However, I keep getting the following error
package,com.google.gms.location does not exist
I wonder what I am missing or doing wrong?
Here is the dll's added into the references from the nuget

Make sure all packages are of the same version (27.0.0)
Make sure Xamarin.Build.Download is installed (it downloads the required .jar files etc.)
Clean & Rebuild the android Project
Try entering Update-Package -Reinstall Xamarin.GooglePlayServices.Locationinto the package manager console
Clean & Rebuild the android Project
Try a higher version number of the package (newer ones are stable too)

If you want to use GooglePlayService. The test device/emulator of your app needs to include Google API. If you are using an emulator you can follow the steps below:
Download Google API System Image for your android API Level through Tools->Android->Android SDK Manager(ex for API Level 25 ):
Create a new Google API Emulator through Tools->Android->Android Emulator Manager->Create:
Clean your project and rebuild it, run your project in this emulator.

Stuck on setup wizard of Android Studio

I am stuck on this screen
Can't perform any further action. Since I already downloaded an SDK, I downloaded this version

Actually android studio try to download all the components of sdk, those which you don't have.
So, it can take a lot time, instead you can disable "Downloading Components" at startup:
Go to the installation directory of Android Studio.
There you will find a folder named "bin".
Inside this folder there is a file named "idea.properties".
Open this file and add the following line to the end of the file:
disable.android.first.run=true
What this will do is disable the check that Android Studio performs on first run and decides to download all that stuff.
If it asks to save the file at some different place instead of overwriting the original one, please check the access permissions to the file.
Hope this will help you.

Remove Android Studio settings dirs for re-run Setup Wizard.
I my case I removed both
C:\Users\bieli\.AndroidStudio4.0
and
C:\Users\bieli\.android

Have you specified custom path to SDK in previous step?? if you do not download the SDK you have to go through custom settings and then specify path to SDK. you are also needed to configure the path to SDK in your environment variables, if you are using window system.

What I found reason for this problem, my SDK was corrupted or damaged. My drive were crashed and I have recovered files by recovering tool, that's why files are get damaged and SDK was not working properly.
Then I redownloaded SDK and its running fine.

Why would Android Studio 1.0 rc start downloading Android SDK without detecting if there existing one?

I've installed Android Studio 1.0 rc and Android SDK in my Archlinux box. But when I try to create a new Android Application, the AS would try to download another set of SDK directly from dl-ssl.google.com. I mean why, why wouldn't it start first and let me configure the SDK path? (I am in mainland China, so the connect will be reset all the times, in another word, AS will not start to workspace.

Looks like that is in the known issues list: http://tools.android.com/knownissues
A bug in Android Studio 1.0 RC1 causes the Setup Wizard to show up and ask you to install an SDK on each startup. To work around this, you can edit the idea.properties file in the bin folder such that it has the below line as well:
disable.android.first.run=true
PLEASE NOTE: This will break patch updating to the next version. We now check full binary checksums on the whole installation to prevent various install corruption bugs as well as to preserve application signatures. Therefore, make a copy of this file first, and before updating, put it back. (Alternatively, just download the full image of RC2 when it is released.)

I am geting an error while building android project?

gen folder is missing is the issue.The build patch failed .I have tried all solutions posted previously on this and no luck.
EDIT
To make it clear here is my original post
https://salesforce.stackexchange.com/questions/9460/encountering-issues-while-developing-android-hybrid-mobile-app
I am using salesforce SDK but when i am creating hello world app using native its working fine

Even if you delete the gen folder, it'll regenerate it after you compile your program.But if it is not then try creating a new project and try it again .If not , try a fresh installation of the API.

Update
Hmm, everyone in both posts is telling you to download the "SDK Platform" for "Android 2.2 (API 8)". I really, really recommend trying this. It is apparently required by the library you added to your project...
I have 4.2 and 4.1 .Is that not enough?
No, you must have the older platforms that you are building against.
Simply download it and open Project > Properties, click on Android, then select Android 2.2. After all this clean your project and save it.
Original Answer
The screenshot doesn't give us much detail, but:
Unable to Resolve target 'android-8'
Tells me that you probably don't have the SDK Platform for API 8, simply download this through the SDK Manager. Or you can change any references in your manifest and the rest of your code to use an API that you already have.

I think it is because when
you import a project, build
target is not set in the
project properties which
then default to the value
used in manifest file. and make sure you have API 8.
The solution is to enable
build target toward your
installed API level (but keep
the minimum api support as
specified in the manifest
file).

Can't find Android Support Package

I have checked all these articles, and I still can't figure out why I can't find the Android Support Package/Library:
Cant' find Android Support package
Android Support package not present in SDK Manager
Can't find Support Package in Android SDK Manager
Cannot find Support Package in Android SDK Manager
This is what the Android SDK Manager is showing me:
I have tried clearing the cache and reloading, but this is what I get.

you just try to reload once again.
if it doesn't work for you use this link to download the support package manually
http://venomvendor.blogspot.in/2012/03/android-sdk-extras-by-google-inc.html
extract the zip and copy it to directory
android-sdk\extras\support
this works for me
you can also try using Android Package Deployer to download API level manually
http://siddharthbarman.com/sidstream/index.php?r=software/apd

Maybe you didn't select "Show Obsolete Packages" in your SDK Manager.
It's in "Packages". Select it and reload.