Android objectBox的使用(kotlin)
程序员文章站
2022-04-12 08:50:04
1.首先是添加依赖;build.gradle(Module:app)buildscript {ext.objectboxVersion = '2.6.0'repositories {jcenter()}dependencies {classpath 'com.android.tools.build:gradle:3.6.2'//添加objectBox依赖classpath "io.objectbox:objectbox-gradle-plugin:$objectb...
1.首先是添加依赖;
build.gradle(Module:app)
buildscript {
ext.objectboxVersion = '2.6.0'
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.6.2'
//添加objectBox依赖
classpath "io.objectbox:objectbox-gradle-plugin:$objectboxVersion"
}
}
build.gradle(Prohect:包名)
apply plugin: 'kotlin-kapt' // objectBox批注处理所必需
apply plugin: 'io.objectbox' // 应用objectBox
然后点击同步,第一步完成;
2.实体类注解
- 必须具有@Id,否则编译不通过
- 必须为var
- 建议给所有的变量赋值
- @Transient表明为非数据库字段
- @NameInDb表示该表中字段的名称
import io.objectbox.annotation.Entity
import io.objectbox.annotation.Id
import io.objectbox.annotation.NameInDb
import io.objectbox.annotation.Transient
@Entity
data class History(
@Id
@NameInDb("S_ID")
var id: Long = 0,
@NameInDb("S_picture")
var picture: String = "",
@NameInDb("S_name")
var name: String = "",
@NameInDb("S_surplusLength")
var surplusLength: Long = 0,
@Transient
var isSelect: Boolean = false
) : BaseModel(){
override fun checkCreate() : Boolean{
return true
}
3.初始化ObjectBox,建议在Application中直接初始化它
- 创建object类
import android.content.Context
import com.bass.noVipVideo.Model.MyObjectBox
import io.objectbox.BoxStore
object ObjectBox {
lateinit var boxStore: BoxStore
fun init(context: Context) {
boxStore = MyObjectBox.builder().androidContext(context).build()
}
}
- 在application中初始化
class BassApplication : Application() {
override fun onCreate() {
super.onCreate()
//初始化objectBox
ObjectBox.init(this)
}
}
4.使用objectBox
import com.bass.noVipVideo.Model.BaseModel
import com.bass.noVipVideo.Model.History
import com.bass.noVipVideo.Util.ObjectBox
class HistoryPresenter : BasePresenter() {
override fun createAsync(model: BaseModel) {
super.createAsync(model)
//向数据库创建一条数据
//如果传进来的mdel的id不为0,则为更新指定id的数据
ObjectBox.boxStore.boxFor(History::class.java).put(model as History)
}
override fun retrieveAsync() : List<BaseModel>?{
super.retrieveAsync()
//向数据库查询返回所有数据
return ObjectBox.boxStore.boxFor(History::class.java).query().build().find()
}
override fun deleteNAsync(historyList: List<BaseModel>) {
for (model in historyList) {
//删除指定id的数据的从表
ObjectBox.boxStore.boxFor(VideoSurface::class.java).remove((model as History).videoSurface.targetId)
//删除指定id的数据
ObjectBox.boxStore.boxFor(History::class.java).remove((model as History).id)
}
}
}
5.使用浏览器查看存储数据
- 添加依赖
dependencies {
debugImplementation "io.objectbox:objectbox-android-objectbrowser:$objectboxVersion"
releaseImplementation "io.objectbox:objectbox-android:$objectboxVersion"
}
// 应用io.objectbox 一定要放在dependencies之后
apply plugin: 'io.objectbox'
- 添加权限
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
- 使用
在模拟器中使用浏览器输入:http://localhost:8090/index.html,界面如下:
本文地址:https://blog.csdn.net/weixin_45379305/article/details/107427075