【发布时间】：2020-09-14 18:42:02
【问题描述】：
我想将我从交易中获得的一些值插入到 Room 数据库中。
我使用 Insert 方法将数据保存到房间数据库中，并使用 @query 从数据库中获取所有数据。
但问题是数据没有保存，当我在屏幕之间切换时没有数据迹象。
代码：
我的桌子
@Entity (tableName = "credit")
data class Credit(
@PrimaryKey(autoGenerate = true)
val id : Int? ,
var credittext: Long
)
我的道：
//credit table dao
@Query("SELECT * FROM credit ")
fun creditall () : LiveData<Credit>
@Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertcredit (model : Credit)
@Query("DELETE FROM credit")
suspend fun deletecredit ()
}
我的仓库：
// repository for Credit
fun getallcredit() = db.GetDao().creditall()
suspend fun deletallcredit() = db.GetDao().deletecredit()
suspend fun insertcredit(model : Credit) = db.GetDao().insertcredit(model)
}
Viewmodel 房间：
// this is for credit tb
fun creditall() = repository.getallcredit()
fun deletecredit() = CoroutineScope(Dispatchers.IO).launch {
repository.deletallcredit()
}
fun insertcredit(model: Credit) = CoroutineScope(Dispatchers.IO).launch {
repository.insertcredit(model)
}
我的房间数据库：
package com.example.ahwazfriut.Room
import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
@Database(entities = [RoomTables::class , Credit::class], version = 1, exportSchema = false)
abstract class DataBaseRoom : RoomDatabase() {
abstract fun GetDao(): DaoCart
companion object {
@Volatile
private var instance: DataBaseRoom? = null
private val lock = Any()
operator fun invoke(context: Context) = instance
?: synchronized(lock) {
instance
?: makeDatabase(
context
).also {
instance = it
}
}
private fun makeDatabase(context: Context) = Room.databaseBuilder(
context.applicationContext,
DataBaseRoom::class.java,
"name"
).build()
}
}
这是我插入和获取数据的活动：
class Payment_Activity : AppCompatActivity() {
lateinit var viewmodel: ViewModelRoom
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.payment_activity)
paymentVerification()
}
private fun paymentVerification() {
val textmoney: TextView = findViewById(R.id.money)
val data: Uri? = intent.data
val getpurchase = ZarinPal.getPurchase(this)
getpurchase.verificationPayment(data) {
isPaymentSuccess, refID, paymentRequest ->
if (isPaymentSuccess) {
val database = DataBaseRoom(this)
val repositoryCart = RepositoryCart(database)
val factoryRoom = FactoryRoom(repositoryCart)
viewmodel = ViewModelProvider(ViewModelStoreOwner { ViewModelStore() } , factoryRoom).get(ViewModelRoom::class.java)
viewmodel.insertcredit(Credit(null , paymentRequest.amount))
viewmodel.creditall().observe(this, Observer {
if (it != null) {
textmoney.text = it.credittext.toString()
}
})
}
谢谢你的帮助。
【问题讨论】：
标签： android database kotlin mvvm