1.数据绑定

1.新建一个User javabean

public class User {    
String username;    
String password;    

public User(String username, String password) {        
this.username = username;        
this.password = password;    
}    

public String getUsername() {        
return username;    
}    

public void setUsername(String username) {        
this.username = username;    
}    

public String getPassword() {        
return password;    
}    

public void setPassword(String password) {        
this.password = password;    
}

}

2.xml文件

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

<data>    
<variable        
type="com.lefeee.dbdemoapplication.bean.User"        
name="user"/>    
 </data>

<LinearLayout    xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" 
tools:context="com.lefeee.dbdemoapplication.MainActivity">  

<TextView        
android:layout_width="wrap_content"    
android:layout_height="wrap_content"     
android:text="@{user.username}" />   

<TextView        
android:layout_width="match_parent"   
android:layout_height="wrap_content"        
android:text="@{user.password}"             
</LinearLayout>
</layout>

3.activity中

public class MainActivity extends AppCompatActivity {    

@Override    
protected void onCreate(Bundle savedInstanceState) {        
super.onCreate(savedInstanceState);   
//  setContentView(R.layout.activity_main); 
      
ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);        
User user1 = new User("yuanlin", "123456");        
binding.setUser( user1 );