Android 安卓DataBinding（一）·基础 Android 安卓DataBinding（二）·入门 Android 安卓DataBinding（三）·单向绑定 BaseObservable Android 安卓DataBinding（四）·单向绑定 ObservableField Android 安卓DataBinding（五）·单向绑定 ObservableCollection（集合使用） Android 安卓DataBinding（六）·双向绑定
在上面有些文章中已经有些事件绑定了，下面来看看事件绑定的具体用法。 android:onClick android:afterTextChanged …
android:afterTextChanged 和 android:onTextChanged 可以用于EditText中
以输入账号密码来进行模拟，模拟使用android:onClick、android:afterTextChanged 和 android:onTextChanged 。跟我一起来做！
修改Bean类： username 和 password 分别表示账号和密，用final来修饰，如果你不知道为什么我要用final修饰，请看我第四篇文章------Android 安卓DataBinding（四）·单向绑定 ObservableField
package com.lkdot.data; import android.databinding.ObservableField; public class DataBean { public final ObservableField<String> username; public final ObservableField<String> password; public DataBean(ObservableField<String> username, ObservableField<String> password) { this.username = username; this.password = password; } public ObservableField<String> getUsername() { return username; } public ObservableField<String> getPassword() { return password; } }MainActivity.java 写出 Listener 内部类，不要忘记 activityMainBinding.setListener(new Listener()); 哦！！！
package com.lkdot.data; import android.annotation.SuppressLint; import android.databinding.DataBindingUtil; import android.databinding.ObservableField; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.text.Editable; import android.view.View; import android.widget.Toast; import com.lkdot.data.databinding.ActivityMainBinding; public class MainActivity extends AppCompatActivity { private ActivityMainBinding activityMainBinding; private DataBean dataBean; @SuppressLint({"SetTextI18n", "InlinedApi"}) @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); activityMainBinding = DataBindingUtil.setContentView(this, 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); dataBean = new DataBean(new ObservableField<String>(), new ObservableField<String>()); activityMainBinding.setData(dataBean); activityMainBinding.setListener(new Listener()); } public class Listener { public void onClick(DataBean dataBean) { Toast.makeText(MainActivity.this, "UserName：" + dataBean.getUsername().get(), Toast.LENGTH_SHORT).show(); } public void afterUserNameChanged(Editable editable) { dataBean.getUsername().set(editable.toString()); } public void afterPasswordChanged(Editable editable) { dataBean.getPassword().set(editable.toString()); } } }布局文件： 注意记得有两个import哦！之后进行事件绑定！
<?xml version="1.0" encoding="utf-8"?> <layout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"> <data> <import type="com.lkdot.data.MainActivity.Listener" /> <import type="com.lkdot.data.DataBean" /> <variable name="listener" type="Listener" /> <variable name="data" type="DataBean" /> </data> <android.support.constraint.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent" android:background="#FFFFFF" tools:context=".MainActivity"> <TextView android:id="@+id/textView4" android:layout_width="match_parent" android:layout_height="30dp" android:layout_marginTop="8dp" android:gravity="left|center" android:paddingLeft="20dp" android:text="username:" app:layout_constraintTop_toTopOf="parent" tools:ignore="MissingConstraints" /> <TextView android:id="@+id/textView5" android:layout_width="match_parent" android:layout_height="45dp" android:background="#03A9F4" android:gravity="left|center" android:onClick="@{() -> listener.onClick(data)}" android:paddingLeft="20dp" android:text="@{data.username}" android:textColor="#FFFFFF" android:textSize="14dp" android:textStyle="bold" app:layout_constraintTop_toBottomOf="@+id/textView4" tools:ignore="MissingConstraints" tools:layout_editor_absoluteX="0dp" /> <TextView android:id="@+id/textView6" android:layout_width="match_parent" android:layout_height="30dp" android:layout_marginTop="15dp" android:gravity="center|left" android:paddingLeft="20dp" android:text="password:" app:layout_constraintTop_toBottomOf="@+id/textView5" tools:ignore="MissingConstraints" tools:layout_editor_absoluteX="0dp" /> <TextView android:id="@+id/textView7" android:layout_width="match_parent" android:layout_height="45dp" android:background="#03A9F4" android:gravity="left|center" android:paddingLeft="20dp" android:text="@{data.password}" android:textColor="#FFFFFF" android:textSize="14dp" android:textStyle="bold" app:layout_constraintTop_toBottomOf="@+id/textView6" tools:ignore="MissingConstraints" tools:layout_editor_absoluteX="0dp" /> <EditText android:id="@+id/editText" android:layout_width="match_parent" android:layout_height="40dp" android:layout_marginTop="25dp" android:afterTextChanged="@{listener.afterUserNameChanged}" android:background="#F2F2F2" android:hint="请输入UserName" android:paddingLeft="20dp" android:textSize="14dp" app:layout_constraintTop_toBottomOf="@+id/textView7" tools:ignore="MissingConstraints" tools:layout_editor_absoluteX="0dp" /> <EditText android:layout_width="match_parent" android:layout_height="40dp" android:layout_marginTop="15dp" android:afterTextChanged="@{listener.afterPasswordChanged}" android:background="#F2F2F2" android:hint="请输入密码" android:paddingLeft="20dp" android:password="true" android:textSize="14dp" app:layout_constraintTop_toBottomOf="@+id/editText" tools:ignore="MissingConstraints" tools:layout_editor_absoluteX="0dp" /> </android.support.constraint.ConstraintLayout> </layout>上面呢，用的是事件监听绑定方法，还有一种方法引用，直接用 :: 即可， 如： android:onClick="@{listener::onClick}" 就是方法引用绑定！
输入密码黑屏了哈，手机自带的，保护密码用的，相信你能看懂
