Android MVVM模式DataBinding的使用 基礎篇；

1、在該module的gradle中配置dataBinding

android {
    ******
    dataBinding {
        enabled true
    }
}

 

2、數據類繼承BaseObservable

public class UserBean extends BaseObservable {

    private String name;
    private Integer age;
    
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

3、配置佈局文件；

佈局文件的根標籤必須是layout，然後配置data和view；

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>
        <variable
            name="user"
            type="com.cuichen.mvvmdemo.bean.UserBean" />
    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:text="@{user.name}" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:text="@{String.valueOf(user.age)}" />

        <Button
            android:id="@+id/btn"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Btn" />
    </LinearLayout>
</layout>

4、在Activity中使用

public class MvvmActivity extends AppCompatActivity {

    private ActivityMainBinding viewDataBinding;
    private UserBean userBean;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        viewDataBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        userBean = new UserBean();
        userBean.setAge(22);
        userBean.setName("USER");
        viewDataBinding.setUser(userBean);

        viewDataBinding.btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                userBean.setAge(999);
                userBean.setName("MVVM");
                viewDataBinding.setUser(userBean);
            }
        });
    }
}

注：ActivityMainBinding 是DataBinding自動生成的，規則是“佈局文件名稱+Binding” ，手動輸入後會提示導入；