*选择你自己工程下的BR或者第三个BR
之后咱再进行一个事件绑定，来修改PeopleBean中得值来更新UI。
使用内部类写出事件Listener，如下：
package com.lkdot.data;
import android.annotation.SuppressLint;
import android.databinding.DataBindingUtil;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
import com.lkdot.data.databinding.ActivityMainBinding;
public class MainActivity extends AppCompatActivity {
private ActivityMainBinding activityMainBinding;
private PeopleBean peopleBean;
@SuppressLint("SetTextI18n")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//这句不用管，是关于安卓状态栏的
getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
activityMainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);
peopleBean = new PeopleBean("NorthernBrain", 25);
activityMainBinding.setPeoPleBean(peopleBean);
activityMainBinding.changeName.setText("改变Name");
activityMainBinding.changeAge.setText("增加Age");
activityMainBinding.setListener(new Listener());
}
public class Listener {
public void changeName() {
peopleBean.setName("改变的名字");
Toast.makeText(MainActivity.this, "改变Name", Toast.LENGTH_SHORT).show();
}
public void changeAge() {
peopleBean.setName2("我要改变所有UI");
peopleBean.setAge(peopleBean.getAge() + 1);
Toast.makeText(MainActivity.this, "改变所有UI", Toast.LENGTH_SHORT).show();
}
}
}
布局文件
再写出布局（跟上两篇文章不是同一个工程）：
直接在布局文件中进行一个事件绑定，先使用 import 将 Listener 导入进来，然后使用 variable 标签进行引用，再以 onClick 进行事件绑定，如下：
android:onClick="@{()->listener.changeName()}"
android:onClick="@{()->listener.changeAge()}"
<layout xmlns:android="schemas.android.com/apk/res/and…"
xmlns:app="schemas.android.com/apk/res-aut…"
xmlns:tools="schemas.android.com/tools">
<variable
name="peoPleBean"
type="PeopleBean" />
<variable
name="listener"
type="Listener" />
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
tools:context=".MainActivity">
<TextView
android:id="@+id/name"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="20dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:background="#03A9F4"
android:gravity="center"
android:textStyle="bold"
android:text="@{peoPleBean.name,default = HelloWorld}"
android:textColor="#FFFFFF"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/age"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginStart="8dp"
android:textStyle="bold"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:background="#03A9F4"
android:gravity="center"
android:text="@{String.valueOf(peoPleBean.age)}"
android:textColor="#FFFFFF"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/name"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/changeName"
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="15dp"
android:layout_marginEnd="4dp"
android:layout_marginRight="4dp"
android:background="#FFB51A"
android:gravity="center"
android:textColor="#FFFFFF"
android:textStyle="bold"
android:onClick="@{()->listener.changeName()}"
app:layout_constraintEnd_toStartOf="@+id/changeAge"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/age" />
<TextView
android:id="@+id/changeAge"
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_marginStart="4dp"
android:onClick="@{()->listener.changeAge()}"
android:layout_marginLeft="4dp"
android:layout_marginTop="15dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:background="#FFB51A"
android:gravity="center"
android:textColor="#FFFFFF"
android:textStyle="bold"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/changeName"
app:layout_constraintTop_toBottomOf="@+id/age" />
</android.support.constraint.ConstraintLayout>
