我正在使用带有动画的constraintLayout使用TransitionManager。
我有以下2种布局
这是我的main_activity.xml
<android.support.constraint.ConstraintLayout
android:id="@+id/constraintLayout"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/image"
android:layout_width="0dp"
android:layout_height="160dp"
android:background="@color/colorPrimary"
app:layout_constraintTop_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"/>
<Button
android:id="@+id/btn"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
android:text="Let's start animating"/>
</android.support.constraint.ConstraintLayout>
这是我的main_activity_alt.xml
<android.support.constraint.ConstraintLayout
android:id="@+id/constraintLayout"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ImageView
android:id="@+id/image"
android:layout_width="0dp"
android:layout_height="160dp"
android:background="@color/colorPrimary"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"/>
<Button
android:id="@+id/btn"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
android:text="Let's start animating"/>
</android.support.constraint.ConstraintLayout>
在我的MainActivity中,我想要将图像设置为向上滑动,这将是main_activity_alt.xml
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val constraintSet1 = ConstraintSet()
constraintSet1.clone(constraintLayout)
val constraintSet2 = ConstraintSet()
constraintSet2.clone(this, R.layout.activity_main_alt)
val transition = ChangeBounds()
transition.duration = 5000
val handler = Handler()
handler.postDelayed({
TransitionManager.beginDelayedTransition(constraintLayout, transition)
constraintSet2.applyTo(constraintLayout)
}, 10)
}
当上述开始时,图像已经显示。 main_activity.xml
应该隐藏,main_activity_alt.xml
将是它的最后安息之地。
但是,当屏幕加载时,它只是立即显示imageview
而没有任何动画
我上面做错了什么?
来自documentation 的beginDelayedTransition:
调用此方法会导致TransitionManager捕获场景根中的当前值,然后发布请求以在下一帧上运行转换。此时,将捕获场景根中的新值,并且将更改动画的更改。
在尝试转换之前,您必须等到布局布局。有很多方法可以做到这一点,但最简单的方法是发布转换代码,如下所示:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val constraintLayout = findViewById<ConstraintLayout>(R.id.constraintLayout)
constraintLayout.post {
val constraintSet1 = ConstraintSet()
constraintSet1.clone(constraintLayout)
val constraintSet2 = ConstraintSet()
constraintSet2.clone(this, R.layout.activity_main2_alt)
val transition = ChangeBounds()
transition.duration = 5000
TransitionManager.beginDelayedTransition(constraintLayout, transition)
constraintSet2.applyTo(constraintLayout)
}
}
尝试延迟转换,以便在转换开始时第一个布局会膨胀
transition.delay = 300
如果这不起作用然后尝试
Handler().postDelayed({do transition here}, 300)