如何删除android中的@InternalCoroutinesApi注解？

Question

我看了很多关于如何使用Room持久化库与coroutine的教程，但每当我在文件中使用coroutine时，它都会强迫我用@InternalCoroutineApi来注释我的代码，但在教程中，他们不需要注释任何东西.现在我想知道1.这个注释是什么意思？2.为什么要这样做？ 3.如何避免这种情况？这个 下面是我创建数据库和build.gradle文件的过程。

import android.content.Context
import androidx.room.Database
import androidx.room.Entity
import androidx.room.Room
import androidx.room.RoomDatabase
import kotlinx.coroutines.InternalCoroutinesApi
import kotlinx.coroutines.internal.synchronized

@Database(entities = [Post::class], version = 1, exportSchema = false)
public abstract class PostRoomDatabase: RoomDatabase() {
    abstract fun getDao(): PostDao
    companion object{
        //Companion object provide the same functionality as the Static keyword in java
        @Volatile
        private var DATABASE_INSTANCE :PostRoomDatabase? = null

        @InternalCoroutinesApi
        fun getDatabase(context: Context) : PostRoomDatabase{
            val tempInstance = DATABASE_INSTANCE
            if(tempInstance != null){
            return tempInstance
            }
            synchronized(this){
                val instance = Room.databaseBuilder(
                    context.applicationContext,
                    PostRoomDatabase::class.java,
                    "post_database"
                ).build()
                DATABASE_INSTANCE = instance;
                return instance
            }
        }
    }
}

Build.gradle文件

    apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'

android {
    compileSdkVersion 28
    buildToolsVersion "29.0.2"

    defaultConfig {
        applicationId "vijay.bhadolia.seed"
        minSdkVersion 23
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

// To inline the bytecode built with JVM target 1.8 into
// bytecode that is being built with JVM target 1.6. (e.g. navArgs)


    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }

}

dependencies {
    def room_version = "2.2.5"
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.core:core-ktx:1.2.0'
    implementation 'com.google.android.material:material:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'androidx.navigation:navigation-fragment:2.2.2'
    implementation 'androidx.navigation:navigation-ui:2.2.2'
    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
    implementation 'androidx.navigation:navigation-fragment-ktx:2.2.2'
    implementation 'androidx.navigation:navigation-ui-ktx:2.2.2'
    testImplementation 'junit:junit:4.13'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
    //Circular images
    implementation 'de.hdodenhof:circleimageview:3.1.0'
    //Room database
    implementation "androidx.room:room-runtime:$room_version"
    kapt "androidx.room:room-compiler:$room_version"


    def coroutines_version = "1.3.0"
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"
}

Answer 1

你的导入中说。

import kotlinx.coroutines.internal.synchronized

这就是它所抱怨的内部API。你不应该为synchronized关键字导入任何东西，所以简单地删除该导入行。