带有关键帧的 Android 矢量可绘制动画

Question

我正在尝试创建矢量可绘制对象的变形动画，如下图所示。

这是动画的全部代码。

vector.xml

<?xml version="1.0" encoding="utf-8" ?> 
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:height="30dp"
    android:width="66dp"
    android:viewportHeight="300"
    android:viewportWidth="660" >
<path
   android:fillColor="#444444"
   android:pathData="@string/leftcircle"/>
<path
   android:fillColor="#444444"
   android:pathData="@string/rightcircle"/>
<path
     android:name="v"
     android:fillColor="#888888"
     android:pathData="@string/path1" />
</vector>

animated_vector.xml

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

path_morph.xml

<objectAnimator
xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:repeatCount="1"
android:repeatMode="reverse">
<propertyValuesHolder
  android:valueType="pathType"
  android:propertyName="pathData">
  <keyframe android:fraction="0" android:value="@string/path1"/>
  <keyframe android:fraction=".25" android:value="@string/path2"/>
  <keyframe android:fraction=".50" android:value="@string/path3"/>
  <keyframe android:fraction=".75" android:value="@string/path4"/>
  <keyframe android:fraction="1" android:value="@string/path5"/>
</propertyValuesHolder>
</objectAnimator>

这里还有strings.xml中的路径数据。

<string name ="path1">M 270,150 C 270,187.37906 252.90964,220.76644 226.11667,242.77442 205.40491,259.78723 178.89511,270 150,270 121.84725,270 95.958829,260.30526 75.491116,244.07216 47.775945,222.09105 30,188.12142 30,150 30,111.70527 47.937943,77.600165 75.869739,55.628783 96.277661,39.575743 122.02056,30 150,30 178.97201,30 205.54599,40.267195 226.2819,57.361549 252.97988,79.370941 270,112.69784 270,150 Z</string>
<string name ="path2">M 270,150 C 270,187.37906 252.90964,220.76644 226.11667,242.77442 205.40491,259.78723 178.89511,270 150,270 121.84725,270 95.958829,260.30526 75.491116,244.07216 47.775945,222.09105 30,188.12142 30,150 30,111.70527 47.937943,77.600165 75.869739,55.628783 96.277661,39.575743 122.02056,30 150,30 178.97201,30 205.54599,40.267195 226.2819,57.361549 252.97988,79.370941 270,112.69784 270,150 Z</string>
<string name ="path3">M 452.83762,150 C 452.83762,205.05673 340.91918,223.02696 310.46441,229.64243 284.27202,235.33202 269.20391,236.28506 240.40866,238.68527 210.11173,241.21065 183.84211,242.12251 161.35408,230.4351 129.96629,214.12233 112.83251,188.6265 112.83251,150.50508 112.83251,112.21035 128.068,86.448772 159.7124,70.275994 186.18123,56.748335 210.11173,59.294424 245.45942,61.314729 274.38422,62.967933 284.69637,65.170902 311.13471,69.988456 344.39869,76.049765 452.83762,90.474484 452.83762,150 Z</string>
<string name ="path4">M 555.87318,152.52538 C 555.87318,207.58211 525.71582,219.24633 496.33248,230.14751 471.20294,239.47054 432.28759,238.60827 405.5686,236.66496 375.18319,234.45499 361.75301,231.64198 336.61554,228.41479 314.31913,225.55234 188.59395,188.6265 188.59395,150.50508 188.59395,112.21035 297.49736,79.662901 343.56017,71.286146 373.38379,65.86257 375.77674,65.35534 409.6092,62.829958 438.50083,60.673379 471.51631,62.981109 497.00278,71.503685 519.66016,79.080223 555.87318,92.999865 555.87318,152.52538 Z</string>
<string name ="path5">M 630,150 C 630,187.41085 612.88056,220.82323 586.04829,242.83055 565.34657,259.80969 538.86332,270 510,270 482.10724,270 456.43718,260.48349 436.05955,244.52022 408.01924,222.5542 390,188.38141 390,150 390,111.54658 408.08691,77.317584 436.21749,55.356271 456.56974,39.467432 482.17925,30 510,30 539.00418,30 565.60499,40.290006 586.35094,57.418512 613.00923,79.428421 630,112.73001 630,150 Z</string>

所以无论我做什么，我都无法使用关键帧来完成这项工作。要么我得到类似的东西：

Method set() with type float not found on target class class android.graphics.drawable.VectorDrawable$VFullPath

或者什么都没有发生。我尝试过使用<animator/> <objectAnimator/>，但似乎唯一可行的是执行动画集，每个<objectAnimator/>都有延迟，这就是gif动画的创建方式。然而这对我不起作用，因为我希望能够为动画添加一个插值器并能够反转它而不是摆弄偏移量和持续时间。

Answer 1

确保在 objectAnimator 上指定 android:valueType="pathType"。