Kotlin-android: unresolved reference databinding

Question

I have following fragment class written in Java using the new databinding library

import com.example.app.databinding.FragmentDataBdinding;

public class Data         


        

Answer 1

To Solve the problem, you have to put

apply plugin: 'kotlin-kapt'

at the top of build.gradle (Module: app), then put this line in dependencies

kapt "com.android.databinding:compiler:[YOUR_ANDROID_PLUGIN_VERSION]"

You can find android plugin version by go to menu

File > Project Structure > Project

Then Sync Again. If you see this warning, ignore it.

3rd-party Gradle plug-ins may be the cause

Answer 2

Configuration data binding in kotlin

build.gradle (folder app)

apply plugin: 'kotlin-kapt'

android {
   ...
   dataBinding {
      enabled = true
   }
}

dependencies {
   // data binding
   kapt "com.android.databinding:compiler:3.1.3"
}

Enjoy Kotlin...

Answer 3

The version of Data Binding compiler is same as gradle version in your project build.gradle file:

// at the top of file 
apply plugin: 'kotlin-kapt'


android {
  dataBinding.enabled = true
}

dependencies {
  kapt "com.android.databinding:compiler:3.0.0-beta1"
}

and the gradle version is

classpath 'com.android.tools.build:gradle:3.0.0-beta1'

Here is an example link to complete using of databinding library in kotlin.

https://proandroiddev.com/modern-android-development-with-kotlin-september-2017-part-1-f976483f7bd6

Answer 4

Important Update

You can see in documentation of Android.

The new compiler in version 3.2 is enabled by default.

So Just Update your Android Studio to V3.2 or newer. and remove all unnecessary config.

So just enable dataBinding in app level build.gradle.

android {
    dataBinding {
        enabled = true
    }
}

It will do all things for you automatically.

You can SAFELY REMOVE below lines-

• Remove databinding.compiler

  kapt 'com.android.databinding:compiler:3.0.1'
  

• Remove kapt

  kapt {
      generateStubs = true
  }
  

My complete config

build.gradle (Project)

kotlin_version = '1.2.71'    
classpath 'com.android.tools.build:gradle:3.2.0'

Use gradle latest version. Use kotlin latest version.

build.gradle (App)

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

compileSdkVersion 28
targetSdkVersion 28

implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

Important Do not just copy and paste config. See this answer for setting up Kotlin version.

gradle-wrapper.properties

distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip

Answer 5

Add following in you app build.gradle

kapt "com.android.databinding:compiler:$android_plugin_version"
apply plugin: 'kotlin-kapt' // This one at top where plugin belong to

This will do the trick.

$android_plugin_version is version of com.android.tools.build:gradle in application build.gradle

Also, add this to your module build.gradle

android { /// Existing Code kapt { generateStubs = true } }

Answer 6

In my case, the error was Unresolved reference: RegisterationUserBinding I just used my layout name fragment_registeration_user like this FragmentRegisterationUserBinding and made it in the Databinding layout and the error went away.