【AndroidX】DataStore API使用示例_android 如何让datastore api 大全

    // Preferences DataStore
    implementation "androidx.datastore:datastore-preferences:1.0.0-alpha02"
 
    // Proto DataStore
    implementation "androidx.datastore:datastore-core:1.0.0-alpha02"
 
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9"
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.2"//kotlin协程

object DataStoreUtil {
 
    private var dataStore: DataStore<Preferences>? = null
    private const val dataStoreName: String = "user"
 
    /**
     * 写入数据
     */
    suspend fun writeDataToDataStore(context: Context, key: String, msg: String) {
        if (dataStore == null) {
            dataStore = context.createDataStore(dataStoreName)
        }
 
        val data = preferencesKey<String>(key)
        dataStore!!.edit { user ->
            user[data] = msg
        }
    }
 
    /**
     * 读取数据
     */
    fun readDataFromDataStore(context: Context, key: String): Flow<String> {
        if (dataStore == null) {
            dataStore = context.createDataStore(dataStoreName)
        }
 
        val data = preferencesKey<String>(key)
        return dataStore!!.data.map { preferences: Preferences -> preferences[data] ?: "" }
    }
}

class MainActivity : AppCompatActivity(), CoroutineScope by MainScope() {
 
    private val keys = arrayOf("测试1", "测试2", "测试3")
    private val tag: String = "DataStoreTest"
 
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        async {
            createData()
        }
        findViewById<TextView>(R.id.my_text).setOnClickListener {
            async {
                getData()
            }
        }
    }
 
    override fun onDestroy() {
        super.onDestroy()
        cancel()
    }
 
    private suspend fun createData() {
        DataStoreUtil.writeDataToDataStore(this, keys[0], "123")
        DataStoreUtil.writeDataToDataStore(this, keys[1], "456")
        DataStoreUtil.writeDataToDataStore(this, keys[2], "789")
    }
 
    private suspend fun getData() {
        val index = abs(Random(System.currentTimeMillis()).nextInt()) % 3
 
        var readDataFromDataStore: Flow<String> =
                DataStoreUtil.readDataFromDataStore(
                        this,
                        keys[index])
        readDataFromDataStore.collect {
            Log.d(tag, it)
        }
    }
}