AAPT: error: resource drawable/spiner_selector (aka com.qifei.ddcpdaapp:drawable/spiner_selector) not found.

This error message indicates that the resource file "spiner_selector.xml" is missing from the "drawable" folder in your project. To fix this error, you need to either create a new "spiner_selector.xml" file in the "drawable" folder or add the missing file to your project. Once the file is added or created, make sure to clean and rebuild your project to ensure that the changes are applied properly.