If you're getting started with the Android SDK and encounter an error message which says "Error: Target id is not valid. Use 'android list targets' to get the target ids'" here's how to solve it...
While you're developing an Android application you'll need to create an Android Virtual Device or AVD, which allows you to test your application before you let it loose on a real 'phone.
The docs tell you to run the following command: android create avd --target 2 --name my_avd However, this gave me the following error "Error: Target id is not valid. Use 'android list targets' to get the target ids."
Running android list targets listed no available targets. This is because the SDK needs some further set-up work to tell it to fetch sources before you can use it.
To get around this problem type android in your terminal. Then click Available sources > check the box and click install selected. It will then go off and download all of the SDK packages via an https repository server at google.com/android.
Now re-run android create avd --target 2 --name my_avd and it should allow you to create the AVD and map it to a target.
但是在检查更新的时候，会出现连接google 仓库失败 connection time out，具体解决办法见我的博客：