eclipse安装ADT时的Missing requirement问题

eclipse安装ADT时，很多朋友（包括我自己）会出现类似如下Missing requirement问题：

Cannot complete the install because one or more required items could not be found.
Software being installed: Android Native Development Tools 21.0.0.v20120310015-519525 (com.android.ide.eclipse.ndk.feature.group 21.0.0.v20120310015-519525)
Missing requirement: Android Native Development Tools 21.0.0.v20120310015-519525 (com.android.ide.eclipse.ndk.feature.group 21.0.0.v20120310015-519525) requires 'org.eclipse.cdt.feature.group 0.0.0' but it could not be found

1. 分析：ADT所带NDK插件需要CDT支持，CDT是EClipse下支持C/C++开始的插件（Eclipse CDT (C/C++ Development Tooling)）
2. 解决办法：先给Eclipse安装CDT插件，打开eclipse，在help - > install new software，输入http://download.eclipse.org/tools/cdt/releases/indigo

出现CDT Main Features, CDT Optional Features和TCF等，选择CDT Main Features就行了，如下图：

3. 安装完CDT现在我们就能安心的安装ADT:

打开 Eclipse IDE，进入菜单中的 "Help" -> "Install New Software"

点击Add...按钮，弹出对话框要求输入Name和Location：Name自己随便取，Location输入http://dl-ssl.google.com/android/eclipse。如下图所示：