Koltin MyClass.class.java未解决的参考：java

Question

在Java Android中，我们使用MyActivity.class开始新活动。我正在玩Android Studio 3 beta1并尝试将其转换为kotlin。它被转换为MyActivity::class.java，但这不会编译。它给了我Unresolved reference: java。什么是正确的等价物？

Project Build.gradle：

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-beta1'
        classpath 'com.google.gms:google-services:3.0.0'

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

allprojects {
    repositories {
        jcenter()
        maven { url "https://jitpack.io" }
    }
}

App Build.gradle：

apply plugin: 'com.android.application'

android {
    signingConfigs {
    }
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    lintOptions {
        abortOnError false
    }
    defaultConfig {
        vectorDrawables.useSupportLibrary = true
        applicationId "app"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 104
        versionName "4.0.11"
    }

    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        debug {
            minifyEnabled false
        }
    }
    flavorDimensions "mode"

    productFlavors {
        free {
            dimension "mode"
        }
        paid {
            dimension "mode"
            applicationId "app.paid"
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}


dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support:support-v4:25.3.1'
    compile 'com.android.support:design:25.3.1'
    compile 'com.android.support:recyclerview-v7:25.3.1'
    compile 'com.android.support:cardview-v7:25.3.1'
    compile 'com.google.android.gms:play-services-ads:10.2.6'
    releaseCompile 'ch.acra:acra:4.9.1'
    //    compile 'ch.acra:acra:4.9.1'
    compile 'com.google.firebase:firebase-core:10.2.6'
    compile 'com.google.firebase:firebase-database:10.2.6'
    compile 'com.google.firebase:firebase-auth:10.2.6'
    compile 'com.google.android.gms:play-services-auth:10.2.6'
    compile 'com.github.frangsierra:rx2firebase:1.1.3'
}

apply plugin: 'com.google.gms.google-services'

Answer 1

尝试在gradle文件中添加以下更改。

在项目build.gradle文件中添加classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.1.3-2"。

的build.gradle（：项目）

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-beta1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.1.3-2" // New 
        classpath 'com.google.gms:google-services:3.0.0'

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

...
...

并添加

apply plugin: 'kotlin-android-extensions' apply plugin: 'kotlin-android'

app build.gradle文件中的两行。

的build.gradle（：应用）

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

android {
    ...
    ...

    ...
    ...
}


dependencies {
    ...
    ...
}

apply plugin: 'com.google.gms.google-services'

这必须解决您的问题，因为我已将“我的Android Studio”更新为3.0 beta 1并遇到此问题。

我希望这有帮助。

Answer 2

我认为这是一个错误。我刚刚更新到beta2，问题解决了。