1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:tools="http://schemas.android.com/tools" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent" 6 tools:context="com.example.administrator.animator_demo2.MainActivity"> 7  8 <Button 9 android:id="@+id/btn_click"10 android:layout_width="wrap_content"11 android:layout_height="wrap_content"12 android:layout_centerInParent="true"13 android:text="Click" />14 15 </RelativeLayout>

 1 package com.example.administrator.animator_demo2; 2  3 import android.animation.Animator; 4 import android.animation.AnimatorListenerAdapter; 5 import android.animation.ObjectAnimator; 6 import android.os.Bundle; 7 import android.support.v7.app.AppCompatActivity; 8 import android.view.View; 9 import android.widget.Button;10 import android.widget.Toast;11 12 public class MainActivity extends AppCompatActivity implements View.OnClickListener {13 14 private Button btn_click;15 16  @Override17 protected void onCreate(Bundle savedInstanceState) {18 super.onCreate(savedInstanceState);19  setContentView(R.layout.activity_main);20  initView();21  }22 23 private void initView() {24 btn_click = (Button) findViewById(R.id.btn_click);25 btn_click.setOnClickListener(this);26  }27 28  @Override29 public void onClick(View v) {30 switch (v.getId()) {31 case R.id.btn_click:32 // startAnimator1();33 /**34  * startAnimator1()方法当中，一下就重写了四个监听方法，在因为有的时候，我们35  * 我们并不需要监听那么多，只需要其中的onAnimationEnd()方法。36  * 那这时我们会选择用startAnimator2()的方式。（两种执行效果相同）37  * */38  startAnimator2();39 break;40  }41  }42 43 private void startAnimator1() {44 //透明动画45 ObjectAnimator animator = ObjectAnimator.ofFloat(btn_click, "alpha", 0F, 1F);46 animator.setDuration(1000);47 //为动画设置监听48 animator.addListener(new Animator.AnimatorListener() {49  @Override50 public void onAnimationStart(Animator animation) {51 52  }53 54  @Override55 public void onAnimationEnd(Animator animation) {56 /**57  * 大部分情况下，我们都要监听的是这个，在动画结束后，执行什么操作58  * 这里，我们只弹出一个Toast。59  * */60 Toast.makeText(MainActivity.this, "动画执行结束", Toast.LENGTH_SHORT).show();61  }62 63  @Override64 public void onAnimationCancel(Animator animation) {65 66  }67 68  @Override69 public void onAnimationRepeat(Animator animation) {70 71  }72  });73  animator.start();74  }75 76 private void startAnimator2() {77 //透明动画78 ObjectAnimator animator = ObjectAnimator.ofFloat(btn_click, "alpha", 0F, 1F);79 animator.setDuration(1000);80 //为动画设置监听81 animator.addListener(new AnimatorListenerAdapter() {82  @Override83 public void onAnimationEnd(Animator animation) {84 super.onAnimationEnd(animation);85 Toast.makeText(MainActivity.this, "动画执行结束", Toast.LENGTH_SHORT).show();86  }87  });88  animator.start();89  }90 }