setSupportActionBar (androidx.appcompat.widget.Toolbar) in AppCompatActivity cannot be applied

Question

An error showing incompatible types Android widget toolbar cannot be converted in Java compiler while working on Android Studio.

    Toolbar toolbar = (Toolb         


        

Answer 1

Change your activity toolbar import to:

import android.support.v7.widget.Toolbar;

Answer 2

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_detail);

    Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
    setSupportActionBar(toolbar); //No Problerm

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}

we must import androidx.appcompat.widget.Toolbar; don't import android.widget.Toolbar;

Answer 3

AndroidX is the new and improved support library

 import androidx.appcompat.widget.Toolbar;

you can check more about from here here

Androidx's toolbar is designed for backwards compatibility while

android.widget.Toolbar

is the current plattform type

Answer 4

This error because your Toolbar created using android.widget.Toolbar . But you are using androidX. This also a same kind of error. java.lang.ClassCastException: androidx.appcompat.widget.Toolbar cannot be cast to android.widget.Toolbar

To solve this kind of you can add these to lines in to your MainActivity.java file (to import).

import androidx.appcompat.app.AppCompatActivity;

import androidx.appcompat.widget.Toolbar;

Make sure to remove or comment out this android.widget.Toolbar . Then again check for error like this. because sometime you may have to import more.

Answer 5

simply delete

import android.widget.Toolbar;

and add

import androidx.appcompat.widget.Toolbar;

Answer 6

Try to replace this:

import android.widget.Toolbar;

With this:

import androidx.appcompat.widget.Toolbar;

By the way, if you are using androidx. Run it's migration process. The android support libraries will not be supported in the future. You can read about it here:

AndroidX Migrating to AndroidX