【Android动画九章】-浮动菜单

上几节讨论了各种各样的属性动画，这里将这些知识组合起来，模拟如下图所示的浮动菜单功能。

1.activity_main.xml:

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent">    <ImageView        android:id="@+id/img1"        android:layout_width="40dp"        android:layout_height="40dp"        android:layout_gravity="bottom|right"        android:layout_margin="20dp"        android:src="@drawable/pic1" />    <ImageView        android:id="@+id/img2"        android:layout_width="40dp"        android:layout_height="40dp"        android:layout_gravity="bottom|right"        android:layout_margin="20dp"        android:src="@drawable/pic2" />    <ImageView        android:id="@+id/img3"        android:layout_width="40dp"        android:layout_height="40dp"        android:layout_gravity="bottom|right"        android:layout_margin="20dp"        android:src="@drawable/pic3" />    <ImageView        android:id="@+id/img_more"        android:layout_width="40dp"        android:layout_height="40dp"        android:layout_gravity="bottom|right"        android:layout_margin="20dp"        android:src="@drawable/more" /></FrameLayout>

父布局采用了FrameLayout布局方式，所有ImageView控件叠在一起放在右下角。
2.MainActivity.java:

package demo.androidwar.com.animatormenu;import android.animation.ObjectAnimator;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.view.animation.BounceInterpolator;import android.widget.ImageView;import android.widget.Toast;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private ImageView imageView1, imageView2, imageView3, imageViewMore;    private boolean isSelected = false;    private List<View> list = new ArrayList<>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initViews();    }    private void initViews() {        imageView1 = (ImageView) findViewById(R.id.img1);        imageView2 = (ImageView) findViewById(R.id.img2);        imageView3 = (ImageView) findViewById(R.id.img3);        imageViewMore = (ImageView) findViewById(R.id.img_more);        imageViewMore.setOnClickListener(this);        imageView1.setOnClickListener(this);        imageView2.setOnClickListener(this);        imageView3.setOnClickListener(this);        list.add(imageView1);        list.add(imageView2);        list.add(imageView3);    }    private void endAnimator() {        isSelected = false;        ObjectAnimator animator = ObjectAnimator.ofFloat(imageViewMore, "rotation", 0F, 360F).setDuration(300);        animator.setInterpolator(new BounceInterpolator());//设置插值器        animator.start();//开始动画        for (int i = 0; i < 3; i++) {            ObjectAnimator.ofFloat(list.get(i), "translationY", -200 * (i + 1), 0F).setDuration(1000).start();        }    }    private void startAnimator() {        isSelected = true;        for (int i = 0; i < 3; i++) {            ObjectAnimator animator = ObjectAnimator.ofFloat(list.get(i), "translationY", 0F, -200 * (i + 1)).setDuration(1000);            animator.setInterpolator(new BounceInterpolator());//设置插值器            animator.start();        }        ObjectAnimator.ofFloat(imageViewMore, "rotation", 0F, 360F).setDuration(300).start();    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.img_more:                if (!isSelected) {                    startAnimator();                } else {                    endAnimator();                }                break;            case R.id.img1:                Toast.makeText(MainActivity.this, "img1", Toast.LENGTH_SHORT).show();                break;            case R.id.img2:                Toast.makeText(MainActivity.this, "img2", Toast.LENGTH_SHORT).show();                break;            case R.id.img3:                Toast.makeText(MainActivity.this, "img3", Toast.LENGTH_SHORT).show();                break;        }    }}

这里核心方法有两个，一个是startAnimator，一个是endAnimator方法。通过遍历每一个ImageView的位移都会乘以相应的倍数。同时为了弹出菜单更生动一些，同时设置了插值器。为每一个菜单设置了单击监听，单击时对应Toast相应信息。运行项目如下：

**喜欢的朋友请关注我，另欢迎阅读我的电子书
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百度阅读：
http://yuedu.baidu.com/ebook/284b41a1e518964bce847c90?pn=1&click_type=10010002&rf=http%3A%2F%2Fblog.csdn.net%2Fyayun0516%2Farticle%2Fdetails%2F51277821
亚马逊：
http://www.amazon.cn/Android-%E7%99%BE%E6%88%98%E7%BB%8F%E5%85%B8-%E5%8D%B7I-%E5%BC%A0%E4%BA%9A%E8%BF%90/dp/B01ER5R9U2?ie=UTF8&keywords=Android%E7%BB%8F%E5%85%B8&qid=1461806976&ref_=sr_1_6&s=digital-text&sr=1-6**