android: data binding error: cannot find symbol class

Question

I am getting started for using DataBinding feature. I am facing problem with it.

Error:(21, 9) error: cannot find symbol class ContactListActivityBinding

build.gradle(Module: app)

apply plugin: 'com.android.application'  android {     compileSdkVersion 23     buildToolsVersion "23.0.2"      defaultConfig {         applicationId "com.letsnurture.ln_202.databindingdemo"         minSdkVersion 15         targetSdkVersion 23         versionCode 1         versionName "1.0"     }     buildTypes {         release {             minifyEnabled false             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'         }     }     dataBinding {         enabled = true     } }  dependencies {     compile fileTree(dir: 'libs', include: ['*.jar'])     testCompile 'junit:junit:4.12'     compile 'com.android.support:appcompat-v7:23.1.1'     compile 'com.android.support:design:23.1.1' } 

ContactListActivity.java

import android.databinding.DataBindingUtil; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.View; import android.view.Menu; import android.view.MenuItem;  import com.letsnurture.ln_202.databindingdemo.model.Contact;  public class ContactListActivity extends AppCompatActivity {      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);          ContactListActivityBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_contact_list);         Contact user = new Contact("Chintan Soni", "+91 9876543210");         binding.setContact(user);  //        setContentView(R.layout.activity_contact_list);         Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);         setSupportActionBar(toolbar);          FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);         fab.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View view) {                 Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)                         .setAction("Action", null).show();             }         });     }      @Override     public boolean onCreateOptionsMenu(Menu menu) {         // Inflate the menu; this adds items to the action bar if it is present.         getMenuInflater().inflate(R.menu.menu_contact_list, menu);         return true;     }      @Override     public boolean onOptionsItemSelected(MenuItem item) {         // Handle action bar item clicks here. The action bar will         // automatically handle clicks on the Home/Up button, so long         // as you specify a parent activity in AndroidManifest.xml.         int id = item.getItemId();          //noinspection SimplifiableIfStatement         if (id == R.id.action_settings) {             return true;         }          return super.onOptionsItemSelected(item);     } } 

content_contact_list.xml

<?xml version="1.0" encoding="utf-8"?> <layout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     tools:context="com.letsnurture.ln_202.databindingdemo.ContactListActivity"     tools:showIn="@layout/activity_contact_list">      <data>          <variable             name="user"             type="com.letsnurture.ln_202.databindingdemo.model.Contact" />     </data>      <LinearLayout         android:layout_width="match_parent"         android:layout_height="match_parent"         android:orientation="vertical"         android:padding="@dimen/activity_horizontal_margin"         app:layout_behavior="@string/appbar_scrolling_view_behavior">          <TextView             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@{user.contactName}"             tools:text="Name" />          <TextView             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@{user.contactNumber}"             tools:text="Number" />     </LinearLayout> </layout> 

activity_contact_list.xml

<?xml version="1.0" encoding="utf-8"?> <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:fitsSystemWindows="true"     tools:context="com.letsnurture.ln_202.databindingdemo.ContactListActivity">      <android.support.design.widget.AppBarLayout         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:theme="@style/AppTheme.AppBarOverlay">          <android.support.v7.widget.Toolbar             android:id="@+id/toolbar"             android:layout_width="match_parent"             android:layout_height="?attr/actionBarSize"             android:background="?attr/colorPrimary"             app:popupTheme="@style/AppTheme.PopupOverlay" />      </android.support.design.widget.AppBarLayout>      <include layout="@layout/content_contact_list" />      <android.support.design.widget.FloatingActionButton         android:id="@+id/fab"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_gravity="bottom|end"         android:layout_margin="@dimen/fab_margin"         android:src="@android:drawable/ic_dialog_email" />  </android.support.design.widget.CoordinatorLayout> 

Answer 1

I consistently run into this problem. I believe it has to do with android studio not being aware of dynamically generated files. If you have everything else right for databinding try to File > Invalidate Caches/Restart... and select Invalidate Caches and Restart. Then try and import the BR file... it should import fine.

You may have to throw in a Clean and Rebuild.