将动画顺序应用于多个视图

动画是状态完整的对象,不应该同时使用同一个实例多次。在你的情况下 bottomToTop 和 fadeIn 动画在动画集之间共享。当集合开始时( initialize() 它将设置其子级的开始偏移。

例如,该方法可能如下所示:

//The function that adds animation to buttonView, with a delay.
private void animateBottomToTop(final View buttonView,long delay) {
    AnimationSet animationSet = new AnimationSet(false);
    // create new instances of the animations each time
    animationSet.addAnimation(createBottomToTop());
    animationSet.addAnimation(createFadeIn());
    animationSet.setStartOffset(delay);
    buttonView.setAnimation(animationSet);
}

这个问题很容易用 Transitions API . 用XML声明根布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/content_frame"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"/>

那么内部活动:

class MainActivity : AppCompatActivity() {

    lateinit var content: LinearLayout
    private var counter = 0

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        content = findViewById(R.id.content_frame)
        // wait this view to be laid out and only then start adding and animating views
        content.post { addNextChild() }
    }

    private fun addNextChild() {
        // terminal condition
        if (counter >= 3) return
        ++counter

        val button = createButton()
        val slide = Slide()
        slide.duration = 500
        slide.startDelay = 100
        slide.addListener(object : TransitionListenerAdapter() {
            override fun onTransitionEnd(transition: Transition) {
                addNextChild()
            }
        })
        TransitionManager.beginDelayedTransition(content, slide)
        content.addView(button)
    }

    private fun createButton(): Button {
        val button = Button(this)
        button.layoutParams = ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)
        button.text = "button"
        return button
    }

}

这段代码将导致以下输出:

您可以分别调整动画和延迟时间。

如果您想要以下行为:

然后可以使用以下代码:

class MainActivity : AppCompatActivity() {

    lateinit var content: LinearLayout

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        content = findViewById(R.id.content_frame)
        content.post { addChildren() }
    }

    private fun addChildren() {
        val button1 = createButton()
        val button2 = createButton()
        val button3 = createButton()

        val slide1 = Slide()
        slide1.duration = 500
        slide1.addTarget(button1)

        val slide2 = Slide()
        slide2.duration = 500
        slide2.startDelay = 150
        slide2.addTarget(button2)

        val slide3 = Slide()
        slide3.duration = 500
        slide3.startDelay = 300
        slide3.addTarget(button3)

        val set = TransitionSet()
        set.addTransition(slide1)
        set.addTransition(slide2)
        set.addTransition(slide3)

        TransitionManager.beginDelayedTransition(content, set)
        content.addView(button1)
        content.addView(button2)
        content.addView(button3)
    }

    private fun createButton(): Button {
        val button = Button(this)
        button.layoutParams = ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)
        button.text = "button"
        return button
    }
}

create方法,它将接受任意数量的 Animation 一个接一个地调用。举个例子。

private void playOneAfterAnother(@NonNull Queue<Animation> anims) {
     final Animation next = anims.poll();

     /* You can set any other paramters, 
     like delay, for each next   Playing view, if any of course */

     next.addListener(new AnimationListener() {
            @Override
            public void onAnimationEnd(Animator a) {
                if (!anim.isEmpty()) {
                    playOneAfterAnother(anims);
                }
            }
            @Override
            public void onAnimationStart(Animator a) {
            }
            @Override
            public void onAnimationCancel(Animator a) {
            }
            @Override
            public void onAnimationRepeat(Animator a) {
            }
        });
     next.play();
}

或者动画延迟,也很容易。

private void playOneAfterAnother(@NonNull Queue<Animation> anims, 
                  long offsetBetween, int nextIndex) {
     final Animation next = anims.poll();

     /* You can set any other paramters, 
     like delay, for each next   Playing view, if any of course */

     next.setStartOffset(offsetBetween * nextIndex);
     next.play();

     if (!anim.isEmpty()) {
         playOneAfterAnother(anims, 
              offsetBetween, nextIndex +1);
     }

}

可能,您需要使用的是animatorset而不是animationset。AnimatorSet API允许您以两种方式编排动画: 1。按顺序播放 2。一起玩耍 使用API:

AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playSequentially(anim1, anim2, anim3, ...);
animatorSet.playTogether(anim1, anim2, anim3, ...);

您可以使用

animatorSet.setStartDelay();

访问此处完整的api文档 https://developer.android.com/reference/android/animation/AnimatorSet

希望这有帮助!