Cannot Resolve ContextCompat in Android

ContextCompat is part of support library v4. Have you added support library 4 to your project?

android.support.v4.content.ContextCompat

You can include support library to your build.gradle file under app folder if you haven’t already

dependencies {
// other stuff here
    compile 'com.android.support:support-v4:23.0.0'
// update the 23.0.0 to latest version available

}