android动画(2)帧动画、矢量图动画

1.官方文档

https://developer.android.com/reference/android/graphics/drawable/AnimationDrawable

https://developer.android.com/guide/topics/graphics/drawable-animation

在res/drawable下可以定义一个帧动画资源，然后在代码中使用它。

2.定义动画资源

animation_frame.xml

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/selected" android:oneshot="true" >
    <!--
        android:drawable    Reference to a drawable resource to use for the frame.
        android:duration    Amount of time (in milliseconds) to display this frame.
        android:oneshot    If true, the animation will only run a single time and then stop.
        android:variablePadding    If true, allows the drawable's padding to change based on the current state that is selected.
        android:visible    Provides initial visibility state of the drawable; the default value is false.
    -->
    <item android:drawable="@drawable/frame1" android:duration="500" />
    <item android:drawable="@drawable/frame2" android:duration="500" />
    <item android:drawable="@drawable/frame3" android:duration="500" />
    <item android:drawable="@drawable/frame4" android:duration="500" />
    <item android:drawable="@drawable/frame5" android:duration="500" />
</animation-list>

3.在资源中使用它

<ImageView
        android:id="@+id/frameImage"
        android:layout_width="64dp"
        android:layout_height="64dp"
        android:background="@drawable/animation_frame"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/frameBtn"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/animation_frame_line" />

4.在代码中使用它

    fun onFrameAnimationClicked(v : View){
        val frameAnimation = binding.frameImage.background as AnimationDrawable
        frameAnimation.start()
    }

5.矢量图动画

　　https://developer.android.com/reference/android/graphics/drawable/AnimatedVectorDrawable

　　https://developer.android.com/guide/topics/graphics/drawable-animation#AnimVector