Android 数据绑定不刷新更改怎么办?
Android databinding does not refresh the changes how can do it?
我有下一个密码
build.gradle
dataBinding {
enabled = true
}
implementation "android.arch.lifecycle:extensions:$lifecycle_version"
LoginActivity.java
import android.arch.lifecycle.Observer;
import android.arch.lifecycle.ViewModelProviders;
import android.databinding.DataBindingUtil;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;
import com.theapp.R;
import com.theapp.databinding.ActivityLoginBinding;
public class LoginActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActivityLoginBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_login);
LoginViewModel loginViewModel = ViewModelProviders.of(this).get(LoginViewModel.class);
binding.setLoginViewModel(loginViewModel);
binding.setLifecycleOwner(this);
loginViewModel.email.observe(this, new Observer<String>() {
@Override
public void onChanged(@Nullable String email) {
Toast.makeText(getApplicationContext(), email, Toast.LENGTH_LONG);
}
});
}
}
activity_login.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data> <variable name="loginViewModel" type="com.theapp.login.LoginViewModel" /> </data>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".login.LoginActivity">
<EditText
android:id="@+id/etxtEmail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
android:ems="10"
android:text="@{loginViewModel.email}"
android:inputType="textEmailAddress"
android:hint="@string/email"
app:layout_constraintBottom_toTopOf="@+id/etxtPassword"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed" />
<EditText
android:id="@+id/etxtPassword"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
android:ems="10"
android:text="@{loginViewModel.email}"
android:inputType="textPassword"
android:hint="@string/password"
app:layout_constraintBottom_toTopOf="@+id/btnRegister"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/etxtEmail" />
<Button
android:id="@+id/btnRegister"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
android:text="@string/login"
android:onClick="@{()-> loginViewModel.onLoginClicked()}"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/etxtPassword" />
</android.support.constraint.ConstraintLayout>
</layout>
LoginViewModel.java
package com.theapp.login;
import android.arch.lifecycle.MutableLiveData;
import android.arch.lifecycle.ViewModel;
import android.util.Log;
import com.theapp.models.User;
import com.theapp.repository.network.APIClient;
import com.theapp.repository.network.APIInterface;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
public class LoginViewModel extends ViewModel {
private APIInterface apiInterface;
public MutableLiveData<String> email = new MutableLiveData<>();
public MutableLiveData<String> password = new MutableLiveData<>();
public LoginViewModel() {
}
}
当我在布局中的电子邮件文本中放置数据时,我希望能够在密码字段中使用该数据,但也可以在 activity 中使用 toast,但是,它没有做任何事情.
我几乎完整地复制了这个 link 的代码,我在两个项目中都留下了相同的 类 而在我的项目中它不起作用,我不知道是不是因为gradle 的依赖关系,或者未知的东西。
有什么想法吗?
对于双向数据绑定,需要使用=
运算符,如:
android:text="@={loginViewModel.email}"
这是单向数据绑定:
android:text="@{loginViewModel.email}"
双向数据绑定的语法如下所示:
android:text="@={loginViewModel.email}"
这 似乎相关。
我有下一个密码
build.gradle
dataBinding {
enabled = true
}
implementation "android.arch.lifecycle:extensions:$lifecycle_version"
LoginActivity.java
import android.arch.lifecycle.Observer;
import android.arch.lifecycle.ViewModelProviders;
import android.databinding.DataBindingUtil;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;
import com.theapp.R;
import com.theapp.databinding.ActivityLoginBinding;
public class LoginActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActivityLoginBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_login);
LoginViewModel loginViewModel = ViewModelProviders.of(this).get(LoginViewModel.class);
binding.setLoginViewModel(loginViewModel);
binding.setLifecycleOwner(this);
loginViewModel.email.observe(this, new Observer<String>() {
@Override
public void onChanged(@Nullable String email) {
Toast.makeText(getApplicationContext(), email, Toast.LENGTH_LONG);
}
});
}
}
activity_login.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data> <variable name="loginViewModel" type="com.theapp.login.LoginViewModel" /> </data>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".login.LoginActivity">
<EditText
android:id="@+id/etxtEmail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
android:ems="10"
android:text="@{loginViewModel.email}"
android:inputType="textEmailAddress"
android:hint="@string/email"
app:layout_constraintBottom_toTopOf="@+id/etxtPassword"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed" />
<EditText
android:id="@+id/etxtPassword"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
android:ems="10"
android:text="@{loginViewModel.email}"
android:inputType="textPassword"
android:hint="@string/password"
app:layout_constraintBottom_toTopOf="@+id/btnRegister"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/etxtEmail" />
<Button
android:id="@+id/btnRegister"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
android:text="@string/login"
android:onClick="@{()-> loginViewModel.onLoginClicked()}"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/etxtPassword" />
</android.support.constraint.ConstraintLayout>
</layout>
LoginViewModel.java
package com.theapp.login;
import android.arch.lifecycle.MutableLiveData;
import android.arch.lifecycle.ViewModel;
import android.util.Log;
import com.theapp.models.User;
import com.theapp.repository.network.APIClient;
import com.theapp.repository.network.APIInterface;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
public class LoginViewModel extends ViewModel {
private APIInterface apiInterface;
public MutableLiveData<String> email = new MutableLiveData<>();
public MutableLiveData<String> password = new MutableLiveData<>();
public LoginViewModel() {
}
}
当我在布局中的电子邮件文本中放置数据时,我希望能够在密码字段中使用该数据,但也可以在 activity 中使用 toast,但是,它没有做任何事情.
我几乎完整地复制了这个 link 的代码,我在两个项目中都留下了相同的 类 而在我的项目中它不起作用,我不知道是不是因为gradle 的依赖关系,或者未知的东西。
有什么想法吗?
对于双向数据绑定,需要使用=
运算符,如:
android:text="@={loginViewModel.email}"
这是单向数据绑定:
android:text="@{loginViewModel.email}"
双向数据绑定的语法如下所示:
android:text="@={loginViewModel.email}"
这