[移动开发]android 数据绑定

gradle添加:
android {
dataBinding{
    enabled true
  }
}

User类

public class User {
    private String name;
    private String age;
    //构造函数
    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;
    }
    public String getAge() {
        return age;
    }
    public void setAge(String age) {
        this.age = age;
    }
}

activity_main布局文件

<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <data>
        <variable
            name="user"
            type="com.example.myapplication.User" />
    </data>
    <RelativeLayout
        android:id="@+id/activity_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context="mvvm.wangjing.com.mvvm.MainActivity">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:text="@{`My name is `+  user.name+`  I'm   `+user.age+`  years old `}" />
    </RelativeLayout>
</layout>

MainActivity类

public class MainActivity extends AppCompatActivity {
    ActivityMainBinding Binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        setContentView(R.layout.activity_main);
        Binding= DataBindingUtil.setContentView(this,R.layout.activity_main);
        User user = new User("jing", "20");
        Binding.setUser(user);
    }
}

出现的问题:第一次发现找不到ActivityMainBinding类，后面我先把布局文件弄好后，再去导入就可以了。

双向绑定

User类修改?Observable方式

public class User {
    public ObservableField<String> name = new ObservableField<>() ;
    public ObservableInt age = new ObservableInt();

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

运行正常，但是User类报红:related problem，我也不知道什么原因，希望大家帮忙改正。