After importing i got that error in compilation:
导入后，我在编译时出现了错误:
java: Cannot find JDK '<unknown>' for module 'CallsFreeCalls'
Also i can't see Android UI Designer inside JI
我也看不到JI里面的Android UI设计师
here what i have inside Project settings:
这里是我在项目内部设置:
i have two choices there, but if i change it, nothing happened :(
我有两个选择，但是如果我改变它，什么也没有发生
this is approving that android designer enabled:
这是对启用android designer的认可:
project SDK:
项目SDK:
platform settings SDKs:
sdk平台设置:
a building problem was solved by adding into platform setting/SDKs Java 1.6 sdk. But i still don't see Android UI Designer anywhere. Project now builded as well, but JI showing error in XML layout files (not actually repeat while building is done): 
通过添加平台设置/SDKs Java 1.6 sdk解决了一个建筑问题。但是我仍然没有看到Android UI设计器。项目现在也构建好了，但是JI在XML布局文件中显示了错误(在构建完成时并没有重复):
1 个解决方案
#1
8
Try the following: select that module in the Project tool window (on the left), and press F4 on it. This will open the Project Structure dialog. Make sure to select your module and the Dependencies tab as shown on the picture:
尝试以下操作:在项目工具窗口(左边)中选择该模块，并按F4。这将打开项目结构对话框。确保选择您的模块和依赖项选项卡，如图所示:
Set your SDK from the Module SDK drop-down.
从模块SDK下拉菜单中设置SDK。
As for the UI Designer: check if the Android Designer plugin is enabled in Settings/Plugins.
至于UI设计器:检查是否在设置/插件中启用了Android设计器插件。
#1
8
Try the following: select that module in the Project tool window (on the left), and press F4 on it. This will open the Project Structure dialog. Make sure to select your module and the Dependencies tab as shown on the picture:
尝试以下操作:在项目工具窗口(左边)中选择该模块，并按F4。这将打开项目结构对话框。确保选择您的模块和依赖项选项卡，如图所示:
Set your SDK from the Module SDK drop-down.
从模块SDK下拉菜单中设置SDK。
As for the UI Designer: check if the Android Designer plugin is enabled in Settings/Plugins.
至于UI设计器:检查是否在设置/插件中启用了Android设计器插件。