Ggtcf

I've created a dummy project to understand Card-Based Layout.
Unfortunately, I am getting cannot resolve symbol errors on RecyclerView.
I'm quite new to programming and can't understand what went wrong.
Dependencies are added to build file:

dependencies 
 implementation fileTree(dir: 'libs', include: ['*.jar'])
 implementation 'com.android.support:appcompat-v7:28.0.0'
 implementation 'com.android.support.constraint:constraint-layout:1.1.3'
 testImplementation 'junit:junit:4.12'
 androidTestImplementation 'com.android.support.test:runner:1.0.2'
 androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
 implementation 'com.android.support:recyclerview-v7:28.0.0'
 implementation 'com.android.support:cardview-v7:28.0.0'

While I'm trying to create a field in Activity I'm getting cannot resolve symbol errors on RecyclerView.

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

 public class MainActivity extends AppCompatActivity 

 RecyclerView recyclerView;

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

when you want to use a class you should import its library.

in this case, you haven't import recyclerview library. to fix this just change your activity code to :

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView; //recyclerview library

 public class MainActivity extends AppCompatActivity 

 RecyclerView recyclerView;

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

Try

• File > Sync Project with Gradle Files

.

Now Remove and start typing the RecyclerView again, it should show up.

You did not import the RecyclerView class, so there's no way your compiler would know what you are talking about. Simply add this line to your import statements:

import android.support.v7.widget.RecyclerView;

Your code should run fine after that.



PS:


To make your programming experience easier, you can just auto-import all the classes you need. Click here to learn more.

I hope this helps.. Merry coding!