ButterKnife 8.0.1 not working

Question

I am using butterknife 8.0.1, but a nullpointerexception is appearing.

This line is on my build.grade file: compile 'com.jakewharton:butterknife:8.0.1'

this is my Main Class: (I wrote the includes properly)

import butterknife.BindView;
import butterknife.ButterKnife;

public class MainActivity extends BaseActivity {

    @BindView(R.id.MainScreenTextView) TextView mainText;

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

        ButterKnife.bind(this);

        **mainText.setText("Butter knife is working fine");**
    }

and this is MainActivity.xml:

<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>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_vertical"
    android:orientation="vertical">

    <TextView
        android:id="@+id/MainScreenTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="This is the Main Screen"
        android:textColor="#000000"
        android:background="#666666"
        android:padding="5dp"
        android:textSize="20dp"/>
</LinearLayout>

<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" />

Answer 1

Per the readme, you need to include the butterknife-compiler in order for the generated code to be produced automatically:

buildscript {
  repositories {
    mavenCentral()
   }
  dependencies {
    classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
  }
}

apply plugin: 'com.neenbedankt.android-apt'

dependencies {
  compile 'com.jakewharton:butterknife:8.0.1'
  apt 'com.jakewharton:butterknife-compiler:8.0.1'
}

Without this there is no generated code to be loaded and thus none of the fields get set.

You can verify ButterKnife is working by calling ButterKnife.setDebug(true) and looking in Logcat.

Answer 2

I used this library in Fragment and has NPE. My code was:

ButterKnife.bind(view);

But it was wrong. Library need to know two objects:
1) Target - with annotations @BindView
2) Source - with views

It will be right to write:

ButterKnife.bind(this, view);

When this - your fragment, and view - view of this fragment.

Answer 3

App Level(build.gradle)

apply plugin: 'android-apt'
dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:appcompat-v7:24.2.1'
    testCompile 'junit:junit:4.12'
    compile 'com.jakewharton:butterknife:8.4.0'
    apt 'com.jakewharton:butterknife-compiler:8.4.0'
}


Project Level(build.gradle)

buildscript {
    repositories {
        jcenter()
    }
    dependencies {

        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

Answer 4

for me the problem was that I was using

annotationProcessor 'com.jakewharton:butterknife-compiler:8.7.0'

instead of

 apt 'com.jakewharton:butterknife-compiler:8.7.0