AndroidStudio : Cannot resolve symbol MainActivity

Question

I got an error \"Cannot resolve symbol MainActivity\" on this code.

Answer 1

It's possible that your 'src' directory isn't set as a source directory?

Your IDE seems to be seeing your com.example.fovoapp as a simple directory structure instead of a package. Also looking at your linked image, the little "J" on the java files tells me that also. When a java file is set as source usually it shows up as a Class "C".

I could be wrong but make sure you set your src directory as source and that should fix the issue.

Answer 2

Clean Caches

File -> Invalidate Caches / Restart...

Answer 3

project structure, right click on src folder->Mark directory as-> sources root.

Now your mainactivity.java file with 'j' symbol to change to 'c' symbol.

The error was that the project did not have a valid source folder from where it could look for the activity class.

Answer 4

set your compatible api level. i also same the face error so i set my api level to 23 in file-> project structure-> app-> flavour -> target sdk version

Answer 5

Maybe you use the wrong path for the src directory.
It should be in the path : ./yourApp/src/main and not ./yourApp/src/androidTest
You can move it manually.

Answer 6

package name on AndroidManifest.xml file and your classes must be same.

AndroidManifest.xml header:

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
   package="com.ahmet.currencies">

Code:

package com.ahmet.currencies;

import ...;


public class MainActivity extends Activity {}