Android,Anko cardView 不可用 - 未解决的参考:cardView

Android, Anko cardView not available - unresolved reference: cardView

我对 android 以及使用 Kotlin 编写应用程序和使用 Anko 生成视图还很陌生。

我想使用 cardView 的 anko 版本,但 android studio 将其突出显示为红色并显示错误 unresolved reference: cardView。如果我按 alt+Enter,则没有添加导入的选项。关于为什么我看不到这个的任何想法?

下面是我的 build.gradle 项目文件。

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'org.jetbrains.kotlin.android.extensions'

android {
    compileSdkVersion 28
    buildToolsVersion '27.0.3'
    defaultConfig {
        applicationId "uk.co.datakitchen.room7"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        vectorDrawables.useSupportLibrary = true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    androidExtensions {
        experimental = true
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.android.support:appcompat-v7:28.0.0-rc02'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    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'
    implementation 'com.android.support:recyclerview-v7:28.0.0-rc02'
    implementation 'com.android.support:cardview-v7:23.0.+'

    implementation "org.jetbrains.anko:anko:$anko_version"
    // Anko Commons
    implementation "org.jetbrains.anko:anko-commons:$anko_version"

    // Anko Layouts
    implementation "org.jetbrains.anko:anko-sdk25:$anko_version" // sdk15, sdk19, sdk21, sdk23 are also available
    implementation "org.jetbrains.anko:anko-appcompat-v7:$anko_version"

    // Coroutine listeners for Anko Layouts
    implementation "org.jetbrains.anko:anko-sdk25-coroutines:$anko_version"
    implementation "org.jetbrains.anko:anko-appcompat-v7-coroutines:$anko_version"
}

删除这一行: 实施 'com.android.support:cardview-v7:23.0.+'

添加这一行: 实施 "org.jetbrains.anko:anko-cardview-v7:$anko_version"