I was very confused when this problem first appeared, because I had been running well before !! I checked a lot of information on the Internet and tried several methods. Let me first tell you how I succeeded.
method 1:
Android Studio 3.0 will automatically add the android:testOnly=”true” attribute to the application tag of the manifest file of the debug apk, so that the apk that runs in the IDE can only be installed with adb install -r on most mobile phones, and on oppo mobile phones It can't even be installed, the solution is: add android.injected.testOnly=false to the gradle.properties file
Method Two:
It may be a problem with Android studio. Check this problem online. There are many solutions. You can refer to this blog http://blog.csdn.net/xiaoyaozaimz/article/details/78555667