Android Studio 看不到 MainActivity

Question

This is a new project created by the android studio. I did not change anything in this project, but in the activity_main.xml file, MainActivity.java can not find, and there is a MainActivity.java file in this project. How I can make this run. (MainActivity.java see activity_main.xml as related )

Answer 1

If you really haven't made any changes prior to this happening, try cleaning and rebuilding the project in the build tab. If it doesn't work, try restarting Android studio.

Answer 2

It's not get accourate path of your package. You can Use com.example.myapplication.MainActivity that times it's work properly.

OR

Invalid caches/restart android studio.

Answer 3

Add your activity to AndroidManifest.xml under <application>

 <activity android:name=".MainActivity" >
        <intent-filter>
      <!-- MAIN represents that it is the Main Activity-->
            <action android:name="android.intent.action.MAIN" />
      <!-- Launcher Denotes that it will be the first launching activity-->
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>