Android dataSotre初次尝试

这个库是google最近出的，用来替代sp，今天出差回来尝试一下。

1、添加依赖包

 // Preferences DataStore
    implementation "androidx.datastore:datastore-preferences:1.0.0-alpha02"//datastore

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

2、编写工具类

package com.lhm.datastore.datastore

import android.content.Context
import androidx.datastore.DataStore
import androidx.datastore.preferences.Preferences
import androidx.datastore.preferences.createDataStore
import androidx.datastore.preferences.edit
import androidx.datastore.preferences.preferencesKey
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.map

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

3、进行读写操作

package com.lhm.datastore

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.TextView
import com.lhm.datastore.datastore.DataStoreUtils
import kotlinx.coroutines.*
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.collect

class MainActivity : AppCompatActivity(),CoroutineScope by MainScope() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        async {
            createData()
        }
        findViewById<TextView>(R.id.tv_getdata).setOnClickListener {
            async {
                getData()
            }
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        cancel()
    }
    private suspend fun createData() {
        DataStoreUtils.writeDataToDataStore(this,"测试")
    }
    private suspend fun getData(){
        var readDataToDataStore: Flow<String> = DataStoreUtils.readDataToDataStore(this)
        readDataToDataStore.collect{
           Log.e("tag",it)
        }
    }
}

这是简单用法，就先这样吧。

本文地址：https://blog.csdn.net/qq939782569/article/details/109387874