ADT是什麼？在開發中起到的作用是什麼？看官方解釋：

ADT Plugin Release Notes   ADT外掛版本說明

The Eclipse ADT plugin is no longer supported per our announcement. Android Studio is now the official IDE for Android, so you should migrate your projects to Android Studio as soon as possible. For more information on transitioning to Android Studio, see Migrate to Android Studio from Eclipse.

Formerly the official IDE solution for Android development,Android Developer Tools (ADT) is a plugin for Eclipse that provides GUI-based access to many of the command-line Android SDK tools.(adt是eclipse的一個外掛，它提供了將諸多android sdk 工具內的命令列轉化為圖形使用者介面操作.；

that指plugin不是eclipse,已哭暈，成功翻譯這句話就能很好理解“這個外掛能讓Eclipse和Android SDK關聯起來。

Revisions

The sections below provide notes about successive releases of the ADT Plugin, as denoted by revision number.

Dependencies:

• Java 7 or higher is required if you are targeting Android 5.0 and higher.
• Java 1.6 or higher is required if you are targeting other releases.
• Eclipse Indigo (Version 3.7.2) or higher is required.
• This version of ADT is designed for use with SDK Tools r24.1.2. If you haven't already installed SDK Tools r24.1.2 into your SDK, use the Android SDK Manager to do so.

General Notes:

• Fixed issues with the rendering library for the visual layout editor.

翻譯過來就是：

Eclipse的ADT外掛不再支援按我們的公告。Android Studio是目前Android官方的IDE，那麼你應該將你的Android Studio專案儘快。在過渡到Android Studio的更多資訊，參見遷移到Android Studio從Eclipse。