(Note: Please refer to another resource I sent in volumes 5 to 9. After downloading, remove 123 from the compressed package and decompress it together. JDK needs to install the Android SDK itself and have the installation files. The API of a specific version needs to be downloaded by itself. There is a solution to the slow online upgrade of the Android SDK. MonoForAndroid. When Mono runs, Monovelop completely passes the test under VS2012Win7)