假设我有一个垂直线性布局:
[v1]
[v2]
默认情况下，v1已经可见= GONE。我想用一个展开动画显示v1，同时下推v2。
我是这样做的:
Animation a = new Animation()
{
int initialHeight;
@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
final int newHeight = (int)(initialHeight * interpolatedTime);
v.getLayoutParams().height = newHeight;
v.requestLayout();
}
@Override
public void initialize(int width, int height, int parentWidth, int parentHeight) {
super.initialize(width, height, parentWidth, parentHeight);
initialHeight = height;
}
@Override
public boolean willChangeBounds() {
return true;
}
};
但是用这个解决方案，当动画开始时我有一个眨眼。我认为这是由于v1在应用动画之前显示全尺寸。
用javascript，这是一行jQuery!android有什么简单的方法吗?
加上Tom Esterez的精彩回答和Erik B的精彩更新，我想我应该发布我自己的观点，将扩展和收缩方法压缩为一个。通过这种方式，你可以有这样一个动作……
button.setOnClickListener(v -> expandCollapse(view));
．.． 它调用下面的方法，并让它在每次onClick()之后弄清楚要做什么…
public static void expandCollapse(View view) {
boolean expand = view.getVisibility() == View.GONE;
Interpolator easeInOutQuart = PathInterpolatorCompat.create(0.77f, 0f, 0.175f, 1f);
view.measure(
View.MeasureSpec.makeMeasureSpec(((View) view.getParent()).getWidth(), View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
);
int height = view.getMeasuredHeight();
int duration = (int) (height/view.getContext().getResources().getDisplayMetrics().density);
Animation animation = new Animation() {
@Override protected void applyTransformation(float interpolatedTime, Transformation t) {
if (expand) {
view.getLayoutParams().height = 1;
view.setVisibility(View.VISIBLE);
if (interpolatedTime == 1) {
view.getLayoutParams().height = ViewGroup.LayoutParams.WRAP_CONTENT;
} else {
view.getLayoutParams().height = (int) (height * interpolatedTime);
}
view.requestLayout();
} else {
if (interpolatedTime == 1) {
view.setVisibility(View.GONE);
} else {
view.getLayoutParams().height = height - (int) (height * interpolatedTime);
view.requestLayout();
}
}
}
@Override public boolean willChangeBounds() {
return true;
}
};
animation.setInterpolator(easeInOutQuart);
animation.setDuration(duration);
view.startAnimation(animation);
}
这是一个片段，我用来调整一个视图(线性布局)的宽度与动画。
代码应该根据目标大小进行扩展或收缩。如果你想要一个fill_parent宽度，你必须在将标志设置为true时将父类. getmeasuredwidth作为目标宽度。
希望它能帮助到你们中的一些人。
public class WidthResizeAnimation extends Animation {
int targetWidth;
int originaltWidth;
View view;
boolean expand;
int newWidth = 0;
boolean fillParent;
public WidthResizeAnimation(View view, int targetWidth, boolean fillParent) {
this.view = view;
this.originaltWidth = this.view.getMeasuredWidth();
this.targetWidth = targetWidth;
newWidth = originaltWidth;
if (originaltWidth > targetWidth) {
expand = false;
} else {
expand = true;
}
this.fillParent = fillParent;
}
@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
if (expand && newWidth < targetWidth) {
newWidth = (int) (newWidth + (targetWidth - newWidth) * interpolatedTime);
}
if (!expand && newWidth > targetWidth) {
newWidth = (int) (newWidth - (newWidth - targetWidth) * interpolatedTime);
}
if (fillParent && interpolatedTime == 1.0) {
view.getLayoutParams().width = -1;
} else {
view.getLayoutParams().width = newWidth;
}
view.requestLayout();
}
@Override
public void initialize(int width, int height, int parentWidth, int parentHeight) {
super.initialize(width, height, parentWidth, parentHeight);
}
@Override
public boolean willChangeBounds() {
return true;
}
}
你可以稍微改变一下使用ViewPropertyAnimator。若要折叠，请将视图缩放到1像素的高度，然后隐藏它。展开，显示它，然后展开到它的高度。
private void collapse(final View view) {
view.setPivotY(0);
view.animate().scaleY(1/view.getHeight()).setDuration(1000).withEndAction(new Runnable() {
@Override public void run() {
view.setVisibility(GONE);
}
});
}
private void expand(View view, int height) {
float scaleFactor = height / view.getHeight();
view.setVisibility(VISIBLE);
view.setPivotY(0);
view.animate().scaleY(scaleFactor).setDuration(1000);
}
枢轴告诉视图从哪里开始缩放，默认是在中间。持续时间是可选的(默认= 1000)。你也可以设置插值器来使用，比如.setInterpolator(new accelerateeraderateinterpolator ())
这是我的解决方案。我认为这样更简单。它只是扩展了视图，但很容易扩展。
public class WidthExpandAnimation extends Animation
{
int _targetWidth;
View _view;
public WidthExpandAnimation(View view)
{
_view = view;
}
@Override
protected void applyTransformation(float interpolatedTime, Transformation t)
{
if (interpolatedTime < 1.f)
{
int newWidth = (int) (_targetWidth * interpolatedTime);
_view.layout(_view.getLeft(), _view.getTop(),
_view.getLeft() + newWidth, _view.getBottom());
}
else
_view.requestLayout();
}
@Override
public void initialize(int width, int height, int parentWidth, int parentHeight)
{
super.initialize(width, height, parentWidth, parentHeight);
_targetWidth = width;
}
@Override
public boolean willChangeBounds() {
return true;
}
}
你可以使用Transition或Animator来改变要展开/折叠的部分的可见性，或者使用不同布局的ConstraintSet。
最简单的一个是使用motionLayout与2个不同的布局和constraintSets改变从一个布局到另一个按钮点击。可以在布局之间进行更改
val constraintSet = ConstraintSet()
constraintSet.clone(this, R.layout.layout_collapsed)
val transition = ChangeBounds()
transition.interpolator = AccelerateInterpolator(1.0f)
transition.setDuration(300)
TransitionManager.beginDelayedTransition(YOUR_VIEW, transition)
constraintSet.applyTo(YOUR_VIEW)
使用过渡api
RotateX.kt
我在gif中使用改变rotationX的过渡api创建了一个。
class RotateX : Transition {
@Keep
constructor() : super()
@Keep
constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
override fun getTransitionProperties(): Array<String> {
return TRANSITION_PROPERTIES
}
override fun captureStartValues(transitionValues: TransitionValues) {
captureValues(transitionValues)
}
override fun captureEndValues(transitionValues: TransitionValues) {
captureValues(transitionValues)
}
override fun createAnimator(
sceneRoot: ViewGroup,
startValues: TransitionValues?,
endValues: TransitionValues?
): Animator? {
if (startValues == null || endValues == null) return null
val startRotation = startValues.values[PROP_ROTATION] as Float
val endRotation = endValues.values[PROP_ROTATION] as Float
if (startRotation == endRotation) return null
val view = endValues.view
// ensure the pivot is set
view.pivotX = view.width / 2f
view.pivotY = view.height / 2f
return ObjectAnimator.ofFloat(view, View.ROTATION_X, startRotation, endRotation)
}
private fun captureValues(transitionValues: TransitionValues) {
val view = transitionValues.view
if (view == null || view.width <= 0 || view.height <= 0) return
transitionValues.values[PROP_ROTATION] = view.rotationX
}
companion object {
private const val PROP_ROTATION = "iosched:rotate:rotation"
private val TRANSITION_PROPERTIES = arrayOf(PROP_ROTATION)
}
}
创建目标扩展按钮的XML文件
<?xml version="1.0" encoding="utf-8"?>
<transitionSet
xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="@android:interpolator/fast_out_slow_in">
<transition class="com.smarttoolfactory.tutorial3_1transitions.transition.RotateX">
<targets>
<target android:targetId="@id/ivExpand" />
</targets>
</transition>
<autoTransition android:duration="200" />
</transitionSet>
My layout to be expanded or collapsed
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<com.google.android.material.card.MaterialCardView
android:id="@+id/cardView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginHorizontal="4dp"
android:layout_marginVertical="2dp"
android:clickable="true"
android:focusable="true"
android:transitionName="@string/transition_card_view"
app:cardCornerRadius="0dp"
app:cardElevation="0dp"
app:cardPreventCornerOverlap="false">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="16dp"
android:paddingBottom="16dp">
<androidx.appcompat.widget.AppCompatImageView
android:id="@+id/ivAvatar"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_marginStart="16dp"
android:layout_marginTop="8dp"
android:scaleType="centerCrop"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:src="@drawable/avatar_1_raster" />
<androidx.appcompat.widget.AppCompatImageView
android:id="@+id/ivExpand"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:padding="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/ic_baseline_expand_more_24" />
<TextView
android:id="@+id/tvTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="12dp"
android:layout_marginTop="6dp"
android:text="Some Title"
android:textSize="20sp"
android:textStyle="bold"
app:layout_constraintStart_toEndOf="@+id/ivAvatar"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/tvDate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:textColor="?android:textColorSecondary"
android:textSize="12sp"
app:layout_constraintStart_toStartOf="@+id/tvTitle"
app:layout_constraintTop_toBottomOf="@id/tvTitle"
tools:text="Tuesday 7pm" />
<TextView
android:id="@+id/tvBody"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:layout_marginEnd="16dp"
android:ellipsize="end"
android:lines="1"
android:text="@string/bacon_ipsum_short"
android:textSize="16sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="@+id/ivAvatar"
app:layout_constraintTop_toBottomOf="@id/tvDate" />
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:orientation="horizontal"
android:overScrollMode="never"
android:visibility="gone"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/tvBody"
tools:listitem="@layout/item_image_destination" />
</androidx.constraintlayout.widget.ConstraintLayout>
</com.google.android.material.card.MaterialCardView>
</layout>
并设置项目的可见性，以折叠或展开
private fun setUpExpandedStatus() {
if (isExpanded) {
binding.recyclerView.visibility = View.VISIBLE
binding.ivExpand.rotationX = 180f
} else {
binding.recyclerView.visibility = View.GONE
binding.ivExpand.rotationX = 0f
}
}
然后开始过渡
val transition = TransitionInflater.from(itemView.context)
.inflateTransition(R.transition.icon_expand_toggle)
TransitionManager.beginDelayedTransition(parent, transition)
isExpanded = !isExpanded
setUpExpandedStatus()
我创建了动画和过渡样本，包括gif上的那个，你可以在那里检查它们。
