Android Studio3.2 Butter Knife配置填坑

Butter Knife github地址：https://github.com/JakeWharton/butterknife/

官方配置方法（有几个坑）:

第一步:在app gradle中添加：

android {
  ...
  // Butterknife requires Java 8.
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}

dependencies {
    implementation 'com.jakewharton:butterknife:10.1.0'
    annotationProcessor 'com.jakewharton:butterknife-compiler:10.1.0'
}

第二步：在project gradle中添加：

dependencies {
    classpath 'com.jakewharton:butterknife-gradle-plugin:10.1.0'
  }

第三步：在app gradle顶部中添加：

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

sync，然后报错

Android Gradle plugin 3.2.1 must not be applied to project 'E:\Android_studio_workspace2\gongxiangdanche\app' since version 3.2.1 was already applied to this project
Open File

Caused by: org.gradle.api.internal.plugins.PluginApplicationException: Failed to apply plugin [id 'com.android.library']

我通过注释掉app gradle里的apply plugin: 'com.android.library’解决了

继续sync,报错

Manifest merger failed : Attribute application@appComponentFactory value=(android.support.v4.app.CoreComponentFactory) from [com.android.support:support-compat:28.0.0] AndroidManifest.xml:22:18-91
 is also present at [androidx.core:core:1.0.0] AndroidManifest.xml:22:18-86 value=(androidx.core.app.CoreComponentFactory).
 Suggestion: add 'tools:replace="android:appComponentFactory"' to  element at AndroidManifest.xml:5:5-47:19 to override.

里面有建议怎么做，试了一下，嗯，不行。

问题的原因是Android Studio3（我的是3.2）配置butterknife对版本有要求，需要9.0.0-rc2以上（我试过8.8.0、8.4.0的都报错），但butterknife10.0.0以上只支持Androidx，如果没有使用androidx配置butterknife10.0.0以上会报这个异常，这里的配置没有使用androidx，是android，所以把butterknife版本换为9.0.0-r2。
参考：https://blog.csdn.net/Night_X/article/details/86653715

再次sync

终于可以用了！
如果出现错误：Error: Static interface methods are only supported starting with Android N (–min-api 24): void butterknife.Unbinder.lambda$static$0()
在app gradle脚本中的android或defaultConfig中添加以下内容，或可解除错误：

// Butterknife requires Java 8.
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }

最终gradle文件：

app gradle:

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

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId ""
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    // Butterknife requires Java 8.
//    compileOptions {
//        sourceCompatibility JavaVersion.VERSION_1_8
//        targetCompatibility JavaVersion.VERSION_1_8
//    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support:support-v4:28.0.0'
    //ProgressBar动画
    implementation 'com.lsjwzh:materialloadingprogressbar:0.5.8-RELEASE'
    //圆形图像
    implementation 'de.hdodenhof:circleimageview:3.0.0'
    //Butter Knife注解
    implementation 'com.jakewharton:butterknife:9.0.0-rc2'
    annotationProcessor 'com.jakewharton:butterknife-compiler:9.0.0-rc2'

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

project gradle：

	buildscript {
    
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
        //Butter Knife注解
        classpath 'com.jakewharton:butterknife-gradle-plugin:9.0.0-rc2'


        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

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

是可以用了，但是generate自动生成代码里面没有自动生成ButterKnife的选择啊。
解决方法：file->Settings->Plugins->Browse Repositories->搜索ButterKnife->选择Android ButterKnife Zelezny->install->restart android studio。

重启后点击资源id R.layout.activity_main里的activity_main，然后alt+Insert弹出

confirm就完成辣。再也不用一个一个findViewById了。