Android 科特林:刚从roomdatabase中得到第一个参数
我的代码有问题,无法解决。 让我们简单介绍一下我将要做的事情:我在ChooseFragment中有一个地址,并且有一个编辑按钮用于编辑地址。好的,到目前为止还不错。编辑点击是将新地址传递到数据库室,地址文本将被更改。但这只是第一次发生。地址未更改的秒结束时间。我知道insert方法可以工作并将新数据发送到数据库室,但当我想通过查询获取数据时,请选择*FROM。。。只显示第一个参数,不替换为新值。我的代码怎么了 这是我的桌子:Android 科特林:刚从roomdatabase中得到第一个参数,android,kotlin,insert,fragment,android-room,Android,Kotlin,Insert,Fragment,Android Room,我的代码有问题,无法解决。 让我们简单介绍一下我将要做的事情:我在ChooseFragment中有一个地址,并且有一个编辑按钮用于编辑地址。好的,到目前为止还不错。编辑点击是将新地址传递到数据库室,地址文本将被更改。但这只是第一次发生。地址未更改的秒结束时间。我知道insert方法可以工作并将新数据发送到数据库室,但当我想通过查询获取数据时,请选择*FROM。。。只显示第一个参数,不替换为新值。我的代码怎么了 这是我的桌子: @Entity (tableName = "addresst
@Entity (tableName = "addresstable")
data class AddressTb(
@PrimaryKey(autoGenerate = true)```
val id : Int? ,
var address: String)```
这是我的数据库:
@Database(entities = [RoomTables::class , AddressTb::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()
}
}```
this is my Dao :
```//address table dao
@Query("SELECT * FROM addresstable")
fun getalladress () : LiveData<AddressTb>
@Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertaddress (model : AddressTb)
@Query("DELETE FROM addresstable")
suspend fun deleteaddress ()
class ManuallyAddressFragment : Fragment() {
lateinit var viewmodel: ViewModelRoom
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val layoutview = inflater.inflate(R.layout.manually_address_fragment, container, false)
val database = DataBaseRoom(layoutview.context)
val repos = RepositoryCart(database)
val factory = FactoryRoom(repos)
viewmodel = ViewModelProvider(ViewModelStoreOwner { viewModelStore },
factory).get(ViewModelRoom::class.java)
val btncancle: Button = layoutview.btn_cancle
val btnsubmit: Button = layoutview.btn_submit_address
btnsubmit.setOnClickListener {
val edittext = layoutview.edit_address_manually
if (edittext.text.toString().isEmpty()) {
Toast.makeText(context, R.string.submit_btn, Toast.LENGTH_SHORT).show()
} else {
val insert = (AddressTb( null , edittext.text.toString()))
viewmodel.insertaddress(insert)
childFragmentManager.beginTransaction()
.setCustomAnimations(
R.anim.anim_fragment_manually,
R.anim.anim_fragment_chooseaddress
)
.replace(R.id.manually_container, ChosseAddress())
.commit()
Toast.makeText(context, "آدرس شما با موفقیت ثبت شد", Toast.LENGTH_SHORT).show()
}
}
btncancle.setOnClickListener {
childFragmentManager.beginTransaction()
.setCustomAnimations(
R.anim.anim_fragment_manually,
R.anim.anim_fragment_chooseaddress
)
.replace(R.id.manually_container, ChosseAddress())
.commit()
}
return layoutview
}
}```
这是我的Viewmodel:
fun getaddress() = repository.getalladdress()
fun deleteaddres() = CoroutineScope(Dispatchers.Default).launch {
repository.deleteaddress()
}
fun insertaddress(model : AddressTb) = CoroutineScope(Dispatchers.Default).launch {
repository.insertaddress(model)
这是我获取新插入的片段:
class ChosseAddress : Fragment() {
lateinit var viewModelRoom: ViewModelRoom
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val vl = inflater.inflate(R.layout.choose_address_layout, container, false)
val database = DataBaseRoom(requireContext())
val repository = RepositoryCart(database)
val factoryRoom = FactoryRoom(repository)
viewModelRoom =
ViewModelProvider(ViewModelStoreOwner { ViewModelStore() }, factoryRoom).get(
ViewModelRoom::class.java
)
viewModelRoom.getaddress().observe(viewLifecycleOwner, Observer {
try {
vl.txt_address.text = it.address
} catch (ex: Exception) {
null
}
})
val animsec: Animation =
AnimationUtils.loadAnimation(vl.context, R.anim.anim_for_btn_zoom_out)
vl.button_back_choose_address.setOnClickListener {
it.startAnimation(animsec)
childFragmentManager.beginTransaction()
.replace(R.id.choose_address_container, HamburgerFragment())
.commit()
}
vl.edit_address.setOnClickListener {
val mycustomview =
LayoutInflater.from(context).inflate(R.layout.alertfialog_costume, null)
val dialogtext = LayoutInflater.from(context).inflate(R.layout.edit_alert_txt, null)
val mBuilder = AlertDialog.Builder(context)
.setView(mycustomview)
.setCustomTitle(dialogtext)
val show = mBuilder.show()
mycustomview.edit_manually.setOnClickListener {
show.dismiss()
childFragmentManager.beginTransaction()
.replace(R.id.choose_address_container, ManuallyAddressFragment())
.commit()
}
}
return vl
}
}```
这就是我向数据库插入数据的地方:
@Database(entities = [RoomTables::class , AddressTb::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()
}
}```
this is my Dao :
```//address table dao
@Query("SELECT * FROM addresstable")
fun getalladress () : LiveData<AddressTb>
@Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertaddress (model : AddressTb)
@Query("DELETE FROM addresstable")
suspend fun deleteaddress ()
class ManuallyAddressFragment : Fragment() {
lateinit var viewmodel: ViewModelRoom
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val layoutview = inflater.inflate(R.layout.manually_address_fragment, container, false)
val database = DataBaseRoom(layoutview.context)
val repos = RepositoryCart(database)
val factory = FactoryRoom(repos)
viewmodel = ViewModelProvider(ViewModelStoreOwner { viewModelStore },
factory).get(ViewModelRoom::class.java)
val btncancle: Button = layoutview.btn_cancle
val btnsubmit: Button = layoutview.btn_submit_address
btnsubmit.setOnClickListener {
val edittext = layoutview.edit_address_manually
if (edittext.text.toString().isEmpty()) {
Toast.makeText(context, R.string.submit_btn, Toast.LENGTH_SHORT).show()
} else {
val insert = (AddressTb( null , edittext.text.toString()))
viewmodel.insertaddress(insert)
childFragmentManager.beginTransaction()
.setCustomAnimations(
R.anim.anim_fragment_manually,
R.anim.anim_fragment_chooseaddress
)
.replace(R.id.manually_container, ChosseAddress())
.commit()
Toast.makeText(context, "آدرس شما با موفقیت ثبت شد", Toast.LENGTH_SHORT).show()
}
}
btncancle.setOnClickListener {
childFragmentManager.beginTransaction()
.setCustomAnimations(
R.anim.anim_fragment_manually,
R.anim.anim_fragment_chooseaddress
)
.replace(R.id.manually_container, ChosseAddress())
.commit()
}
return layoutview
}
}```
我尝试过使用update metohd,但数据库只是返回第一个参数,我想要新的插入值…对于初学者,如果您获得所有地址,它应该如下所示:
@Query("SELECT * FROM addresstable")
fun getalladress () : LiveData<List<AddressTb>>
@Query("SELECT * FROM addresstable WHERE id= :id")
fun findAddressById(id: Long) : AddressTb
要更新该值,请使用相同的id,正如在代码中我看到您尝试插入新对象AddressTbnull、edittext.text.toString。如果要为id传递null值,请从要更新的AddressTb对象传递从getalladdress获得的相同id。否,我不想要所有地址。我希望新值替换旧值。类似somting的更新。但更新也不起作用,但编写的函数毫无意义,也不起作用。它被称为getAllAddresses,SQLite查询从addresstable中选择所有地址。这意味着它将返回AddressTb对象的列表。那么,我应该使用什么代码从数据库表中返回插入的值呢?不是所有我用你的代码编辑的列表,但不知道我应该在这里传递什么!!!viewModelRoom.getaddress???.observeviewLifecycleOwner,观察者{try{vl.txt_address.text=it.toString}捕获示例:异常{null}传入要获取的地址的id。您有一个满是地址的表,id是唯一标识每个地址的长id。如果需要表中的第一个地址,请使用1。