Android Jetpack组件DataBinding详解

android {
    dataBinding {
        enabled = true
    }
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ActivityMainBinding mainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
    .......................
}

// 单向刷新的第一种方式
public class User extends BaseObservable {

    private String name;
    private String age;

    public User(String name, String age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
        // 全量刷新
        notifyChange();
    }

    @Bindable
    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
        // 单一刷新
        notifyPropertyChanged(BR.age);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<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">
	<!--绑定数据-->
    <data>
		
        <variable
            name="user"
            type="com.example.databingding.User" />

    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        tools:context=".MainActivity">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:text="@{user.age}"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:text="@{user.name}"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:text="改变参数"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    </LinearLayout>
</layout>

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityMainBinding mainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        User user = new User("张三", "60");
        mainBinding.setUser(user);
        mainBinding.button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                user.setAge("30");
                user.setName("李思");
            }
        });
    }
}

// 单向刷新的第二种方式
public class Bean {

    public ObservableField<String> id = new ObservableField<>();

    public ObservableField<String> name = new ObservableField<>();

}

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@={user.name}" />