仿今日头条刷新vector动画

一般的刷新动画是一个圈圈在转，而头条的比较特殊，直接上写好的效果图(一直不知道怎么把图片尺寸调小o(╯□╰)o)吧~

刷新动画_.gif

首先整个效果是通过SVG和vector来实现的，如果不是很了解，请看大佬的文章：
SVG学习--AnimatedVectorDrawable的使用
动画思路：
整个view可以分为五个部分：
1、最外面的壳（不需要动画）
2、中间矩形框
3、矩形框中的灰色矩形块
4、三根短线
5、三根长线

第一步：在drawable文件夹下新建名为refresh的vector文件：

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="200dp"
    android:height="200dp"
    android:viewportHeight="200"
    android:viewportWidth="200">
    <!--外面大框-->
    <path
        android:name="out_rect"
        android:pathData="M70,60
                          L130,60
                          Q140,60 140,70
                          L140,130
                          Q140,140 130,140
                          L70,140
                          Q60,140 60,130
                          L60,70
                          Q60,60 70,60"
        android:strokeColor="@color/colorCustomHeaderLine"
        android:strokeWidth="2" />
    <!--小长方形框-->
    <path
        android:name="middle_rect"
        android:pathData="M71,75
                          L100,75
                          L100,95
                          L72,95
                          L72,75"
        android:strokeColor="@color/colorCustomHeaderLine"
        android:strokeWidth="2" />
    <!--里面的正方形-->
    <path
        android:name="inner_rect"
        android:fillColor="@color/colorCustomHeaderInner"
        android:pathData="M73,76
                          L99,76
                          L99,94
                          L73,94" />
    <!--短线条-->
    <path
        android:name="short_lines"
        android:pathData="M108,75
                          L128,75
                          M108,85
                          L128,85
                          M108,95
                          L128,95"
        android:strokeColor="@color/colorCustomHeaderLine"
        android:strokeWidth="2" />
    <!--长线条-->
    <path
        android:name="long_lines"
        android:pathData="
                          M72,105
                          L128,105
                          M72,115
                          L128,115
                          M72,125
                          L128,125"
        android:strokeColor="@color/colorCustomHeaderLine"
        android:strokeWidth="2" />
</vector>

打开xml右边的预览，我们可以看到效果

效果图.png

第二步：在drawable文件夹下新建名为refresh_vector的animated-vector

<?xml version="1.0" encoding="utf-8"?>
<animated-vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/refresh">
    <target
        android:name="middle_rect"
        android:animation="@animator/anim_middle_rect" />

    <target
        android:name="short_lines"
        android:animation="@animator/anim_short_lines" />

    <target
        android:name="long_lines"
        android:animation="@animator/anim_long_lines" />

    <target
        android:name="inner_rect"
        android:animation="@animator/anim_inner_rect" />

</animated-vector>

这里需要注意几点：
1、android:drawable="@drawable/refresh"这里一定要引用上面的refresh文件
2、target标签下的name一定要和refresh中的path标签下的名字一致

第三步：新建animator文件夹（不是anim），并在下面新建短线、长线、中间矩形框和里面矩形对应的objectAnimator集合：

anim_middle_rect.xml:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="sequentially">
    <!--中间长方形-->
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M71,75
                          L100,75
                          L100,95
                          L72,95
                          L72,75"
        android:valueTo="M99,75
                         L128,75
                         L128,95
                         L100,95
                         L100,75"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M99,75
                         L128,75
                         L128,95
                         L100,95
                         L100,75"
        android:valueTo="M99,105
                         L128,105
                         L128,125
                         L100,125
                         L100,105"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M99,105
                         L128,105
                         L128,125
                         L100,125
                         L100,105"
        android:valueTo="M71,105
                         L100,105
                         L100,125
                         L72,125
                         L72,105"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M71,105
                         L100,105
                         L100,125
                         L72,125
                         L72,105"
        android:valueTo="M71,75
                          L100,75
                          L100,95
                          L72,95
                          L72,75"
        android:valueType="pathType" />

</set>

anim_short_lines.xml:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="sequentially">
    <!--起点为短线-->
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M108,75
                          L128,75
                          M108,85
                          L128,85
                          M108,95
                          L128,95"
        android:valueTo="M72,105
                          L128,105
                          M72,115
                          L128,115
                          M72,125
                          L128,125"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M72,105
                          L128,105
                          M72,115
                          L128,115
                          M72,125
                          L128,125"
        android:valueTo="M72,105
                         L92,105
                         M72,115
                         L92,115
                         M72,125
                         L92,125"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M72,105
                         L92,105
                         M72,115
                         L92,115
                         M72,125
                         L92,125"
        android:valueTo="M72,75
                        L128,75
                        M72,85
                        L128,85
                        M72,95
                        L128,95"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M72,75
                        L128,75
                        M72,85
                        L128,85
                        M72,95
                        L128,95"
        android:valueTo="M108,75
                          L128,75
                          M108,85
                          L128,85
                          M108,95
                          L128,95"
        android:valueType="pathType" />
</set>

anim_long_lines.xml:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="sequentially">
    <!--开始为长线-->
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M72,105
                          L128,105
                          M72,115
                          L128,115
                          M72,125
                          L128,125"
        android:valueTo="M72,75
                         L92,75
                         M72,85
                         L92,85
                         M72,95
                         L92,95"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M72,75
                         L92,75
                         M72,85
                         L92,85
                         M72,95
                         L92,95"
        android:valueTo="M72,75
                        L128,75
                        M72,85
                        L128,85
                        M72,95
                        L128,95"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M72,75
                        L128,75
                        M72,85
                        L128,85
                        M72,95
                        L128,95"
        android:valueTo="M108,105
                          L128,105
                          M108,115
                          L128,115
                          M108,125
                          L128,125"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M108,105
                          L128,105
                          M108,115
                          L128,115
                          M108,125
                          L128,125"
        android:valueTo="M72,105
                          L128,105
                          M72,115
                          L128,115
                          M72,125
                          L128,125"
        android:valueType="pathType" />
</set>

anim_inner_rect.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="sequentially">
    <!--里面的长方形-->
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M73,76
                          L99,76
                          L99,94
                          L73,94"
        android:valueTo="M101,76
                         L127,76
                         L127,94
                         L101,94"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M101,76
                         L127,76
                         L127,94
                         L101,94"
        android:valueTo="M101,106
                         L127,106
                         L127,124
                         L101,124"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M101,106
                         L127,106
                         L127,124
                         L101,124"
        android:valueTo="M73,106
                         L99,106
                         L99,124
                         L73,124"
        android:valueType="pathType" />
    <objectAnimator
        android:duration="500"
        android:interpolator="@android:interpolator/decelerate_cubic"
        android:propertyName="pathData"
        android:valueFrom="M73,106
                         L99,106
                         L99,124
                         L73,124"
        android:valueTo="M73,76
                          L99,76
                          L99,94
                          L73,94"
        android:valueType="pathType" />

</set>

最后一步，在activity中：

<ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

 final AnimatedVectorDrawable animatedVectorDrawable = (AnimatedVectorDrawable) ContextCompat.getDrawable(this, R.drawable.refresh_vector);
                findViewById(R.id.imageView).setImageDrawable(animatedVectorDrawable);
                animatedVectorDrawable.start();
                //循环动画貌似只能这样。。。
                final Handler mainHandler = new Handler(Looper.getMainLooper());
                animatedVectorDrawable.registerAnimationCallback(new Animatable2.AnimationCallback() {
                    @Override
                    public void onAnimationEnd(Drawable drawable) {
                        mainHandler.post(new Runnable() {
                            @Override
                            public void run() {
                                animatedVectorDrawable.start();
                            }
                        });
                    }
                });