在8.0之前butterknife在Module Library中使用有bug，仔細觀察原來是由於引用R資源欄位不是常量所導致在Bind的時候找不到id，8.0之後修復了這個bug，原文：

To use Butter Knife in a library, add the plugin to your buildscript:

buildscript {
  repositories {
    mavenCentral()
   }
  dependencies {
    classpath 'com.jakewharton:butterknife-gradle-plugin:8.4.0'
 

  }
}

and then apply it in your module:

apply plugin: 'com.android.library'
apply plugin: 'com.jakewharton.butterknife'

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;
...
}

①、Project的gradle檔案配置

dependencies {
    classpath 'com.android.tools.build:gradle:2.3.1'
classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
classpath 'com.jakewharton:butterknife-gradle-plugin:8.5.1'
// NOTE: Do not place your application dependencies here; they belong
 
    // in the individual module build.gradle files
}

apply plugin: 'com.android.library'
apply plugin: 'com.jakewharton.butterknife'
apply plugin: 'com.neenbedankt.android-apt'

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:appcompat-v7:23.2.1'
compile 'com.android.support:design:23.1.1'
compile 'com.jakewharton:butterknife:8.5.1'
apt 'com.jakewharton:butterknife-compiler:8.5.1'
}

③、主Module的gradle檔案配置

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

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
})
    compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha8'
testCompile 'junit:junit:4.12'
compile 'com.jakewharton:butterknife:8.5.1'
apt 'com.jakewharton:butterknife-compiler:8.5.1'
compile project(':nimLib')
}

注意在做分支語句請使用if-else代替switch-case不然會報錯。。。。