Paste_Image.png

Paste_Image.png

使用

app build.grable

android {
.......
    dataBinding{
        enabled=true;
    }
}

xml外面包裹一层<layout>

<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
...
</layout>

去除findViewById

  binding.firstName.setText("FirstName");
  binding.lastName.setText("LastName");

xml中:

 <TextView
        android:id="@+id/first_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

 <TextView
        android:id="@+id/last_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

变量绑定

public class Employee {
    public String firstName;
    public String lastName;

    public Employee(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }
}

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

    <data>
        <variable
            name="employee"
            type="myapplication3.xt.com.myapplication.Employee"/>
   </data>

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

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="请输入firstName" />

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="请输入lastName" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{employee.firstName}"
            />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{employee.lastName}"
            />

    </LinearLayout>
</layout>

public class MainActivity extends AppCompatActivity {

    private Employee employee=new Employee("Zhang","San");

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityMainBinding binding= DataBindingUtil.setContentView(this,R.layout.activity_main);
        // binding.setEmployee(employee);
        //或
        binding.setVariable(BR.employee,employee);
    }
}

事件绑定

方法引用

public class MainActivity extends AppCompatActivity {

    private Employee employee=new Employee("Zhang","San");
    private ActivityMainBinding binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
         binding= DataBindingUtil.setContentView(this,R.layout.activity_main);
        binding.setEmployee(employee);
        binding.setPresenter(new Presenter());
    }
    public class Presenter{
       public void onTextChanged(CharSequence s, int start, int before, int count){
           employee.firstName= s.toString();
           binding.setEmployee(employee);
       }
    }
}

<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>
        <variable
            name="employee"
            type="myapplication3.xt.com.myapplication.Employee"/>
        <variable
            name="presenter"
            type="myapplication3.xt.com.myapplication.MainActivity.Presenter"/>
    </data>

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

        <EditText
            android:onTextChanged="@{presenter.onTextChanged}"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="请输入firstName" />

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="请输入lastName" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{employee.firstName}"
            />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{employee.lastName}"
            />

    </LinearLayout>
</layout>

onClick(方法引用)

public class Presenter{
       public void onTextChanged(CharSequence s, int start, int before, int count){
           employee.firstName= s.toString();
           binding.setEmployee(employee);
       }

        public void onClick(View view){
            Toast.makeText(MainActivity.this, "点到了", Toast.LENGTH_SHORT).show();
        }
    }

<TextView
            android:onClick="@{presenter.onClick}"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{employee.firstName}"
            />

监听器绑定

  public class Presenter{
       public void onTextChanged(CharSequence s, int start, int before, int count){
           employee.firstName= s.toString();
           binding.setEmployee(employee);
       }

        public void onClick(View view){
            Toast.makeText(MainActivity.this, "点到了", Toast.LENGTH_SHORT).show();
        }

        public  void  onClickListenerBinding(Employee employee){
            Toast.makeText(MainActivity.this, employee.lastName, Toast.LENGTH_SHORT).show();
        }
    }

   <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{employee.lastName}"
            android:onClick="@{()->presenter.onClickListenerBinding(employee)}"
            />

Paste_Image.png

Paste_Image.png