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);
}
平滑动画请使用Handler运行方法.....享受展开/折叠动画
class AnimUtils{
public void expand(final View v) {
int ANIMATION_DURATION=500;//in milisecond
v.measure(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
final int targtetHeight = v.getMeasuredHeight();
v.getLayoutParams().height = 0;
v.setVisibility(View.VISIBLE);
Animation a = new Animation()
{
@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
v.getLayoutParams().height = interpolatedTime == 1
? LayoutParams.WRAP_CONTENT
: (int)(targtetHeight * interpolatedTime);
v.requestLayout();
}
@Override
public boolean willChangeBounds() {
return true;
}
};
// 1dp/ms
a.setDuration(ANIMATION_DURATION);
// a.setDuration((int)(targtetHeight / v.getContext().getResources().getDisplayMetrics().density));
v.startAnimation(a);
}
public void collapse(final View v) {
final int initialHeight = v.getMeasuredHeight();
Animation a = new Animation()
{
@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
if(interpolatedTime == 1){
v.setVisibility(View.GONE);
}else{
v.getLayoutParams().height = initialHeight - (int)(initialHeight * interpolatedTime);
v.requestLayout();
}
}
@Override
public boolean willChangeBounds() {
return true;
}
};
// 1dp/ms
a.setDuration(ANIMATION_DURATION);
// a.setDuration((int)(initialHeight / v.getContext().getResources().getDisplayMetrics().density));
v.startAnimation(a);
}
}
使用下面的代码调用:
private void setAnimationOnView(final View inactive ) {
//I am applying expand and collapse on this TextView ...You can use your view
//for expand animation
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
new AnimationUtililty().expand(inactive);
}
}, 1000);
//For collapse
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
new AnimationUtililty().collapse(inactive);
//inactive.setVisibility(View.GONE);
}
}, 8000);
}
其他解决方案是:
public void expandOrCollapse(final View v,String exp_or_colpse) {
TranslateAnimation anim = null;
if(exp_or_colpse.equals("expand"))
{
anim = new TranslateAnimation(0.0f, 0.0f, -v.getHeight(), 0.0f);
v.setVisibility(View.VISIBLE);
}
else{
anim = new TranslateAnimation(0.0f, 0.0f, 0.0f, -v.getHeight());
AnimationListener collapselistener= new AnimationListener() {
@Override
public void onAnimationStart(Animation animation) {
}
@Override
public void onAnimationRepeat(Animation animation) {
}
@Override
public void onAnimationEnd(Animation animation) {
v.setVisibility(View.GONE);
}
};
anim.setAnimationListener(collapselistener);
}
// To Collapse
//
anim.setDuration(300);
anim.setInterpolator(new AccelerateInterpolator(0.5f));
v.startAnimation(anim);
}
利用Kotlin扩展函数这是测试和最短的答案
在任何视图上调用animateVisibility(expand/collapse)即可。
fun View.animateVisibility(setVisible: Boolean) {
if (setVisible) expand(this) else collapse(this)
}
private fun expand(view: View) {
view.measure(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)
val initialHeight = 0
val targetHeight = view.measuredHeight
// Older versions of Android (pre API 21) cancel animations for views with a height of 0.
//v.getLayoutParams().height = 1;
view.layoutParams.height = 0
view.visibility = View.VISIBLE
animateView(view, initialHeight, targetHeight)
}
private fun collapse(view: View) {
val initialHeight = view.measuredHeight
val targetHeight = 0
animateView(view, initialHeight, targetHeight)
}
private fun animateView(v: View, initialHeight: Int, targetHeight: Int) {
val valueAnimator = ValueAnimator.ofInt(initialHeight, targetHeight)
valueAnimator.addUpdateListener { animation ->
v.layoutParams.height = animation.animatedValue as Int
v.requestLayout()
}
valueAnimator.addListener(object : Animator.AnimatorListener {
override fun onAnimationEnd(animation: Animator) {
v.layoutParams.height = targetHeight
}
override fun onAnimationStart(animation: Animator) {}
override fun onAnimationCancel(animation: Animator) {}
override fun onAnimationRepeat(animation: Animator) {}
})
valueAnimator.duration = 300
valueAnimator.interpolator = DecelerateInterpolator()
valueAnimator.start()
}
这是一个合适的工作解决方案，我已经测试过了:
例如：
private void expand(View v) {
v.setVisibility(View.VISIBLE);
v.measure(View.MeasureSpec.makeMeasureSpec(PARENT_VIEW.getWidth(), View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
final int targetHeight = v.getMeasuredHeight();
mAnimator = slideAnimator(0, targetHeight);
mAnimator.setDuration(800);
mAnimator.start();
}
崩溃:
private void collapse(View v) {
int finalHeight = v.getHeight();
mAnimator = slideAnimator(finalHeight, 0);
mAnimator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animator) {
}
@Override
public void onAnimationEnd(Animator animator) {
//Height=0, but it set visibility to GONE
llDescp.setVisibility(View.GONE);
}
@Override
public void onAnimationCancel(Animator animator) {
}
@Override
public void onAnimationRepeat(Animator animator) {
}
});
mAnimator.start();
}
动画师的值:
private ValueAnimator slideAnimator(int start, int end) {
ValueAnimator mAnimator = ValueAnimator.ofInt(start, end);
mAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
//Update Height
int value = (Integer) valueAnimator.getAnimatedValue();
ViewGroup.LayoutParams layoutParams = llDescp.getLayoutParams();
layoutParams.height = value;
v.setLayoutParams(layoutParams);
}
});
return mAnimator;
}
视图v是要被动画的视图，PARENT_VIEW是包含该视图的容器视图。
