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Android Build a Weather App (2015) Hooking Up the Model to the View Using Butter Knife for Views

Thomas Williams
Thomas Williams
9,447 Points
Posted by Thomas Williams
Thomas Williams
9,447 Points

Error: @BindView not applicable to local variable or cannot resolve 'R2'......

My gradle Module: app code:

apply plugin: 'com.android.application'

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

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.3"
    defaultConfig {
        applicationId "grouppay.com.stormy"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}



dependencies {
    compile 'com.jakewharton:butterknife:8.4.0'
    apt 'com.jakewharton:butterknife-compiler:8.4.0'
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:24.2.1'
    testCompile 'junit:junit:4.12'
    compile 'com.squareup.okhttp3:okhttp:3.4.1'
}

My gradle Project: Stormy code:

buildscript {
    repositories {
        jcenter()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.1'
        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
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

My MainActivity code:

 @BindView(R.id.timeLabel) TextView mTimeLabel;
        @BindView(R2.id.humdityLabel) TextView mHumidityValue;

For @BindView(R.id.timeLabel) TextView mTimeLabel; i get @BindView not applicable to local variable error.

As per the the instructions on the butternife readMe file...

Now make sure you use R2 instead of R inside all Butter Knife annotations.

class ExampleActivity extends Activity { @BindView(R2.id.user) EditText username; @BindView(R2.id.pass) EditText password; ... }

I tried '@BindView(R2.id.humdityLabel) TextView mHumidityValue;' but got cannot resolve R2.

Any help/solutions/advice before i give up on butterknife will be truly appreciated.

3 Answers

Seth Kroger
Seth Kroger
56,414 Points
Seth Kroger
Seth Kroger
56,414 Points

Annotations can be defined to be used only in certain contexts. For instance @Override only makes sense with methods, so it's definition says it's used to only annotate methods. The same goes for custom annotations. Unless the annotation is generally applicable, it's best to define what it can be used for. Java Annotations goes over this if you're interested.

BindView.java:

@Retention(CLASS) @Target(FIELD)
public @interface BindView {
  /** View ID to which the field will be bound. */
  @IdRes int value();
}

@BindView (and @InjectView as well) is defined to be used on member fields only. When you say "i get @BindView not applicable to local variable error." it's quite literal. You should pull them out of the method (onCreate() I'm guessing?) and make them private member variables.

Steve Hunter
Steve Hunter
57,712 Points
Steve Hunter
Steve Hunter
57,712 Points

Hi Thomas,

I did this project some time ago so there will have been updates to both Android Studio and ButterKnife. I'm using Butterknife 6.1.0.

In my module's build.gradle, I have:

dependencies {
  .
  .
  compile 'com.jakewharton:butterknife:6.1.0'
  .
  .
}

In my MainActivity I am injecting the view with:

@InjectView(R.id.timeLabel) TextView mTimeLabel;
@InjectView(R.id.humidityValue) TextView mHumidityValue;

protected void onCreate(Bundle savedInstanceState){
  .
  .
  ButterKnife.inject(this);
  .
}

So, that uses @InjectView rather than @BindView.

As I say, this may be due to the earlier project using earlier versions of ButterKnife - that version is likely to still work; maybe try backdating the version number to get the code working, then try the updates?

I hope that helps; it probably doesn't!

Steve.

Thomas Williams
Thomas Williams
9,447 Points
Thomas Williams
Thomas Williams
9,447 Points

I cant believe thats what it was, what a muppet, think I was focusing too much on the gradle code because i'm not so familiar with it. Pulling the code out of onCreate() and placing them as member variables solved my problem. Many thanks.