Develop Reference

Target Framework only shows up to API 23

I can't seem to select other API higher than Marshmallow
It is said here than the framework that you can select depends on the version of Xamarin, but my version is already v8.x
Other forums also said to install the SDK Platform for your target framework, but even if I installed API 27, it still didn't show up in the target framework
I also updated the tools to the latest version
How to add the other API to the selection? What other things did I missed?

Which Android SDK Packages do I need for Cordova and Android 4+

I installed cordova and all the required things. Now I have to choose in the Android Sdk Manager which packages I want to install. I want to make the App working for Android 4 and above. I have installed SDK Platform API 14 (ANDROID 4.0) and SDK Platform API 24 (ANDROID 7.0). Do I need more because I also want to cover all the version between this range?

Refer to this: cordova.apache.org/docs/en/latest/guide/platforms/android

How can I change the defined API version of an Android app?

I am absolutly new in Android development and I have the following problem trying to build a sample project that I have downloaded from Internet.
When I try to build it I obtain the following error message:
Error:Cause: failed to find target with hash string 'android-18' in: C:\Users\Andrea\AppData\Local\Android\sdk
Install missing platform(s) and sync project
So I search online and I found this SO link: Android studio - Failed to find target android-18
Ok so I go into Tools > Android > SDK Manager and infact I have installed Android 6 corrisponding to the API level 23 but not Android 4.3 corrisponding to API level 18.
So what it means? It means that I have installed a different version o the Android framework ?(is it the SDK considerable as a framework or what?)
So, on Android Studio can I install different version of the SDK?
I think that the API level have to be defined in some way into the dowloaded application. How can I specify to this application to don't use the API level 18 but instead it use the installed API level 23 ? I think that it is not a problem because I have installed a newest version that have to support all the stuff of the oldest one, is it?

I will explain the problem a bit for you and then provide you with the solution.
You are facing this problem, because your project is targeting API level 18 to compile the project. So you MUST have API 18 SDK installed to compile the project.
This is why the IDE is complaining that,
Install missing platform(s) and sync project
The SDK is not the framework. The Android framework is same all over, but with different API levels new updates are pushed to the SDK, the latest being API 23, Marshmallow.
You should not download an older SDK to compile the project.
Always try to use the latest SDK available to work with. So, just head over to your build.gradle file or AndroidManifest.xml file and change the compileSdkVersion to 23.

You can either change the compileSdkVersion version in build.gradle to 23 or whatever version you have in your local machine
You can obtain the API Level 18 from the SDK Manager.

I go into Tools > Android > SDK Manager and infact I have installed Android 6 corrisponding to the API level 23 but not Android 4.3 corrisponding to API level 18.
So what it means? It means that I have installed a different version of the Android framework ?
Yes, you have a newer version of the SDK.
on Android Studio can I install different version of the SDK?
Yes, that is what the SDK Manager is designed for
I think that the API level have to be defined in some way into the dowloaded application. How can I specify to this application to don't use the API level 18 but instead it use the installed API level 23 ?
It is defined. Check either the AndroidManifest.xml or the build.gradle file in the module for the app (not in the project root). You should see some combination of minSdk, targetSdk, and/or compileSdk with a number after it. Since you are getting an error about missing SDK 18, then that number will be 18.
I think that it is not a problem because I have installed a newest version that have to support all the stuff of the oldest one, is it?
The support libraries are separate from the core SDK. You cannot run SDK 23 specific code on devices that have a version less than 23, therefore, to be safe, it is recommended that you start with downloading SDK 18, then run it, then try updating the compileSdkVersion number.

Android minimum app sdk, required sdks for compilation and compatibility issues

I'm new to android and i want make some things clear about some confusions:
If i set my new android application to a minimum sdk version to 4.0.3 (api 15) should i install all sdks between that version and the latest one ? Or should i just install the sdk level same the device/emulator i will use for testing has as plateform version?
What about when i will generate the final apk for the appstore which will be supposed to work in all android platform versions starting from the min sdk i've targeted ?
i was reading about the Android Support Library and i guess it should be always part of the latest sdk. if i use it on my application should i still have earlier sdk versions installed for the compilation ? Won't i never need anymore packages from earlier API version once i use the support library ?
Best regards.

You do not need the SDK for the minimum version. You only need to work with the SDK of the Target/Maximum version.
Download the platform tools and platform through the SDK manager for the Target API version. And if you use features that are not available in the minimum version, use Android Support Libraries.

The purpose of setting your Minimum SDK is to let devices know if they'll be able to run the code based on what SDK they're using. You don't need to have all versions of the SDK, just the most recent one that you're developing for. If you're using Android Development Studio, it will warn you if a feature you're trying to implement is not supported by the Minimum SDK you've set for the project.

On which Android devices is uiautomator available?

I want to use uiautomator or uiautomatorviewer for Android test automation.
Can I use these tools on any Android device?

You must have a device with Android OS version 4.1 (JELLY_BEAN, API level 16) at minimum. Documentation reference:
To use these tools, you must have the following versions of the Android development tools installed:
Android SDK Tools, Revision 21 or higher
Android SDK Platform, API 16 or higher