Develop Reference

Unity cannot find Android SDK on Windows

I installed Android Studio (3.6.2) along with Android SDK, but when I choose its folder in Unity (Edit -> Preferences -> External Tools), it says "Unable to detect SDK in the selected directory." What do I have to do to make it work? I use Unity 2018.4 (LTS) on Windows 10.

Unity seems to have trouble with folder structure of SDK installed with Android Studio. It seems it expects command line tools to contain folder called tools, but Android Studio stores those in cmdline-tools\latest. Assuming the SDK is installed in C:\Users\{username}\AppData\Local\Android\Sdk you have to do the following:
Copy folder C:\Users\{username}\AppData\Local\Android\Sdk\cmdline-tools\latest to C:\Users\{username}\AppData\Local\Android\Sdk\
Rename latest to tools
In the end you should have a folder called C:\Users\{username}\AppData\Local\Android\Sdk\tools present. It should contain bin and lib folders. When you choose Sdk folder in Unity, it processes it and you should be able to build Android apk.
I have no idea if this is the right approach, but we were able to make Android builds work on Windows following these steps.

Windows update apparently deleted Android SDK files from Visual Studio

I just restarted my Windows 10 machine to install some updates, and afterward I started getting this error in Visual Studio:
Error Xamarin.Android for Visual Studio requires Android SDK.
Please install it or set Android SDK path on Tools->Options->Xamarin->Android Settings menu. 0
Which I thought was weird, since I'd never run into any issues with my Android SDK before. So I went to Tools->Android to open the SDK manager, but all the options were grayed out and not selectable. Here's a screenshot:
So I did a little research, and this post told me to manually start my SDK manager with the .exe file. So I searched my files for the SDK manager, but when I clicked to open it, I got this error message:
The item that this shortcut refers to has been changed or moved.
Would you like to remove this shortcut?
And I got the same error for the Uninstall Android SDK Tools and AVD Manager shortcuts. So it seems that all my Android SDK files were for some reason deleted during my Windows updates.
Then I noticed that under Visual Studio Tools->Options->Xamarin->Android, the "Android SDK Location" was empty. Screenshot:
So then I downloaded Android Studio from the official site, found the location to the .exe file, and then copy-and-pasted the path into the "Android SDK Location" field, and clicked "OK". But the field wasn't saved. No matter what I do, when I open Options, the "Android SDK Location" field is always empty.
I have no idea how to proceed. Anyone have any ideas?
UPDATE
I ran Visual Studio Installer, clicked Modify, and under "Individual Components", it tells me that I already have the latest Android SDK setup (API level 25) installed. Do I need to install something other than that? Screenshot:

Better to Update Visual studio from Visual studio Installer
When you Load Visual Studio Installer, select repair option...
it will fix all issues...

First, Android SDK Location path is Android SDK path not .exe file path.
Second, check the path C:\Program Files (x86)\Android\android-sdk which is default path to store Android SDK by Visual Studio to see whether it exists. In my computer like this:
If it doesn't exists, it maybe have been deleted by your computer update process.
Why the "Android SDK Location" field is always empty is because the path is wrong.
You can also get Android SDK path with the Android Studio which you have downloaded:
Android Stuido -> File -> Settings -> Appearance & Behavior -> System Settings -> Android SDK, then copy-and-pasted the Android SDK Location path to Visual Studio. Find it like this in Android Studio:

Sdk Manager not opening from eclipse

SDK Manager is not opening from eclipse. An initialization screen comes but the SDK Manager doesn't open. I have tried renaming android.bat file but that doesnt work. Re-installing has also been tried.

The possible reason for this to happen is you might have installed the plugin in a wrong way or the destination of the file might have changed by some means.
Make sure these 2 are correct on the 1st place.
If you are confident about these 2 are proper. Make sure the actual SDK_Manager.exe runs directly from its folder destination if double clicked.
which will be present in your android SDK path--->\Android\android-sdk\SDK Manager.exe

Open android.bat in sdk/tools folder by right click on it and click edit
find the line-
set java_exe=
edit it to your path to java.exe like
set java_exe=C:\Program Files\Java\jre7\bin\java.exe
then delete the next line which is
call lib\find_java.bat
This one worked for me......
Check out this link......

After 2 days of frustration not getting solution to launch SDK Manager manually and in Eclipse. Finally, I figured out the solution and whatever solution available elsewhere is not correct on recent development. Thought of adding this info of Android SDK for new to mobile testing enthusiast:
Android encourages users to use Android IDE, so you don't find Android ADT bundle zip file in the site. You may need to download from untrusted source if you want to configure SDK to Eclipse manually.
Solution:
Download JDK, install it, set environment variables for JDK and JRE in your system. (if not sure, please see videos of how to install JDK)
Download Eclipse, unzip it and launch Eclipse
In Eclipse, Go to Windows and click Install new software
Enter this url in work-with: https://dl-ssl.google.com/android/eclipse/ and press Enter
Select Developer Tools checkbox and click Next and finish
Click Ok for permission in popup
Click OK to restart Eclipse
Click Cancel in setting SDK in preferences
Parallely, Android Installation Tool windows opens up, click next
Select automatically downloading Android SDK tools and api versions
It downloads all required tool, it restarts the eclipse, sets preferences,
Now you can launch SDK Manager from Eclipse or go to SDK tools folder and launch Android in tools folder.

The reason of this is using newer version of android sdk tools.
Eclipse supports sdk tools version 25.2.5 and build-tools version 25.0.3. The reason is google has removed some optional/deprecated tools from sdk tools in release 25.3.0. But eclipse needs them to work with android projects. So the thing you can do is delete tools folder from your sdk and download eclipse supported version
Android SDK Tools:
https://dl-ssl.google.com/android/repository/tools_r25.2.5-windows.zip
https://dl-ssl.google.com/android/repository/tools_r25.2.5-linux.zip
https://dl.google.com/android/repository/tools_r25.2.5-macosx.zip
Extract them in your sdk installation directory.
You can now access to SDK manager by using the android command, which is located in tools directory of your sdk. You can also do this from eclipse.
Note that Eclipse supports build-tools version 25.0.3 and older, so you will have to download them. For other tools you can select latest version. They are supported by eclipse.

Android Studio SDK Managed Disabled

I just downloaded the Android Studio .dmg for OSX. Per the installation instructions, I've dragged it to the application folder and launched the application.
But the SDK Manager and AVD Manager are greyed out and are impossible to use.
Any ideas on an installation step I may have missed?

For people coming for this same problem for Windows: you won't have an Android SDK anywhere if it is your first time with Android. Also, here the Android Studio doesn't come with a packed SDK Manager, so you need to download one.
So this is what you may do:
Download the SDK Manager and an Android SDK
Download the SDK Manager from: http://developer.android.com/sdk/. Use the link that says "Get the SDK for an existing IDE".
Execute the downloaded installer.
Execute this program with administrator rights: SDK Manager.exe
Download the proposed SDK (if you get errors regarding the SDK Manager couldn't create some folders, remember it should be executed as administrator).
Configure Android Studio to work with the new SDK
Open Android Studio and in the Quick Start window click "Configure", you will see the SDK Manager greyed out.
Go to "Project Defaults", then to "Project Structure" and there it will ask for the path where you installed the SDK.
If you click OK and go back you will see the SDK Manager is no longer greyed out, and now you can start creating projects.

A project needs to have been loaded at least once for the link to become available.
Found it in :
File / Project Structure...
Then in "Android SDK" provide the path to the SDK folder inside the Android Studio Application Bundle.
Then Make a new project.
Then after the initial setup the elements where finally enabled.

Android Studio Beta v0.8.14 with the Android SDK for Mac does not appear to include the SDK: you need to install the SDK manually (e.g. https://developer.android.com/sdk/installing/index.html?pkg=tools) and then configure Android Studio to find and use it.
(I ended up using the ADT bundle, since I couldn't seem to find the SDK as a standalone download.)
You need to use the buttons on the welcome dialog, and not on the applications menu bar or preferences (as I had initially thought). Step by step:
(Note that "SDK Manager" is greyed out until you complete this, at which point you cannot undo it for the purposes of taking screenshots...)
Navigate back and the "SDK Manager" button on the "Configure" panel should be enabled. Clicking it should display something like this:

I had a similar problem and the cause was that I've used path with a space in it. There was a warning in the window that can cause problems with NDK, but in fact it caused problems with Android Studio internal SDK as well. After changing the path it works fine.

Go to configure -> project defaults -> project structure
give the path for the SDK and press OK.
It should work now

For Mac Users (Android Studio Beta v0.8.14)
The SDK or SDK manager is not included with this version of Android Studio, and the documentation is obfuscated regarding this change at this point.
Download the standalone SDK from here. You may select the latest revision of the same from this link below the title GET THE SDK FOR AN EXISTING IDE.
Extract the downloaded zip, and rename the folder as sdk
Copy the sdk folder into the Android Studio.app/Contents directory
Restart Android Studio and you will be shown this dialog when the Android Studio starts up

To remove grey out area,
you need to follow this steps as below:
Go to File
Click on Project Structure
Go to SDK Location
Click on Browse to find SDK path
Select proper SDK path on your system
Now click on SDK manager icon on Android Studio toolbar
I hope this solves the problem of grey out area.
Thanks,

This will no longer be a problem when version 1.0 is released. In the meanwhile you can download the latest canary build (1.0 RC2), which downloads the SDK during the setup.

For me, the issue was on windows and it was as simple as launching the installer with "administrative" mode. That's it!

How do you add an SDK to Android Studio?

I'm using Google's Android Studio 0.1 based on IntelliJ, and I cannot figure out how to add additional SDKs to my project.
I exported my existing project from Eclipse to a Gradle project, which I imported into Android Studio, as recommended by Google.
My project's SDK is Google APIs 2.3.3. However, I use a library called PullToRefresh which appears to need SDK 4.1, so I'm trying to add the SDK 16 to my project.
I've already made sure to download the SDK using the SDK manager. These SDKs are added to the Android Studio.app's sdk folder automatically.
I opened the Project Structure window, clicked "SDKs" under Platform Settings, and I currently see JDK 1.7 and Google APIs 2.3.3 shown. I click the + sign above that list to add a new SDK. I then navigate to the sdk directory that has android-16, as shown in the screenshot below. I am not quite sure what this wants me to add, but I've highlighted the android-16 folder (about the only thing I can select), and when I click "Choose," the window disappears, but no new SDK appears in the SDK list.
And here is a screenshot of my SDK Manager view, showing the installed SDKs:

I had opened a ticket also with Google's support, and received the solution. Instead of choosing the sdk/platform/android-16 folder, if you select the top-level "sdk" folder instead, you'll then be asked to choose which SDK you want to add. This worked!

You have to put your SDK's in a given directory or .app directory. You have to do it in finder while you are out of the application i'm assuming, but personally I'd use terminal in Mac instead of doing it in the App itself or finder. According to Google:
On Windows and Mac, the individual tools and other SDK packages are saved within the Android Studio application directory. To access the tools directly, use a terminal to navigate into the application and locate the sdk/ directory. For example:
Windows: \Users\<user>\AppData\Local\Android\android-studio\sdk\
Mac: /Applications/Android\ Studio.app/sdk/

You can change from the "build.gradle" file the line:
compileSdkVersion 18
to the sdk that you want to be used.

I had to restart Android Studio for changing the sdk after installing a new one. Then Android Studio asked me for configuring my SDK and let me do it.

And For linux(ubuntu)
/usr/share/android-studio/data/sdk

Download your sdk file, go to Android studio: File->New->Import Module

I followed almost the same instructions by #Mason G. Zhwiti , but had to instead navigate to this folder to find the SDK:
/Users/{my-username}/Library/Android/sdk
I'm using Android Studio v1.2.2 on Mac OS

For those starting with an existing IDEA installation (IDEA 15 in my case) to which they're adding the Android SDK (and not starting formally speaking with Android Studio), ...
Download (just) the SDK to your filesystem (somewhere convenient to you; it doesn't matter where).
When creating your first project and you get to the Project SDK: bit (or adding the Android SDK ahead of time as you wish), navigate (New) to the root of what you exploded into the filesystem as suggested by some of the other answers here.
At that point you'll get a tiny dialog to confirm with:
Java SDK: 1.7 (e.g.)
Build target: Android 6.0 (e.g.)
You can click OK whereupon you'll see what you did as an option in the Project SDK: drop-down, e.g.:
Android API 23 Platform (java version "1.7.0_67")