视图将不会与数据绑定

Question

我使用的是View模型和DataBinding。我有一些数据是从服务器上获取的，应该传递给ui。我在那里写了这个视图模型类：

class ProfileViewModel(val context: Context) : ViewModel() {
private val viewModelJob = Job()
private val scope = CoroutineScope(Dispatchers.Main + viewModelJob)
val name = MutableLiveData<String>()
val subscription = MutableLiveData<String>()
val followers = MutableLiveData<String>()
val following = MutableLiveData<String>()
val signals = MutableLiveData<String>()
val image = MutableLiveData<String>()

fun getUserInfo() {
scope.launch {
withContext(Dispatchers.Default) {
val request =
JsonObjectRequest(Request.Method.POST, Address().UserInfoAPI, null,
Response.Listener {
name.value = it.getString("name")
image.value = it.getString("image")
subscription.value = it.getString("subscription")
followers.value = it.getString("followers")
following.value = it.getString("following")
signals.value = it.getString("signals")
}, Response.ErrorListener {
Log.i("Log", "error $it")
})
val queue = Volley.newRequestQueue(context)
queue.add(request)
}
}
}



override fun onCleared() {
super.onCleared()
scope.cancel()
}
}

我在xml布局中使用了这个视图模型，如下所示：

<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="viewModel"
type="com.app.main.profile.ProfileViewModel" />
</data>

<!--- this is just one sample of my elements------>
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{viewModel.name}"
android:textAppearance="@style/vazir_font"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/avatarHolder" />

</layout>

这是我的片段代码：

class ProfileFragment : Fragment() {
private lateinit var binding: FragmentProfileBinding
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_profile, container, false)
return binding.root
}

override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
val factory = ProfileViewModelFactory(context!!)
val viewModel = ViewModelProvider(this, factory).get(ProfileViewModel::class.java)
viewModel.getUserInfo()
binding.viewModel = viewModel

binding.exit.setOnClickListener {
Utils(context!!).isLoggedIn = false
}
}

}

我的问题是TextViews不会填充服务器响应，它们仍然是空的。我该如何解决这个问题？

Answer 1

在binding = DataBindingUtil.inflate(inflater, R.layout.fragment_profile, container, false)之后尝试添加以下内容：

binding.lifecycleOwner = this

它应该能解决这个问题。

Answer 2

试试吧，我想你忘了，name就是MutableLiveData。如果我们想访问，那么需要name.value。

<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@{viewModel.name.value}"
android:textAppearance="@style/vazir_font"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/avatarHolder" />