Android Project R is lost due to the loss of r files of the android project.

Android Project R is lost due to the loss of r files of the android project.

Today began to learn Android, for a long time did not open eclipse, the establishment of the Android project is always an error, so the hand residual to delete the appcompat-v7, and then the establishment of the project after the re-Come Out Of The appcompat-v7 has a cross number, baidu had a good time, so I thought I had to change the SDK version.

Right-click the appcompat-v7 and select properties to set the SDK version to 5.1.1

Then create an Android project. At first, I chose

Then an error is reported, and no R file exists.

 

Come on later

Change to 5.1.1, and then that's right. The R file is also in

I am making this mistake. Pay attention to the casual name of the package, and I am also using the project name in Chinese. I don't know what's going on. It turns out that it is okay, it's probably not a good environment. It's just for your reference.