CodePudding user response:
Start the simulator, you should first solve the problem of error code, you can, the mouse to click the red words AppCompatAxtivity, hold down the Alt + enter, see if there is no import packages, sum up package import good, yesCodePudding user response:
Changes to the build. Gradle inDependencies {
Implementation 'com. Android. Support: appcompat - v7: +'}