如何在Android上动画化视图的背景颜色变化?
例如:
我有一个红色背景色的视图。视图的背景颜色变为蓝色。我怎样才能在颜色之间平滑过渡呢?
如果视图不能做到这一点,那么另一种选择是受欢迎的。
如何在Android上动画化视图的背景颜色变化?
例如:
我有一个红色背景色的视图。视图的背景颜色变为蓝色。我怎样才能在颜色之间平滑过渡呢?
如果视图不能做到这一点,那么另一种选择是受欢迎的。
当前回答
添加一个文件夹动画到res文件夹。(名称必须是animator)。添加一个动画资源文件。例如res/animator/fade.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<objectAnimator
android:propertyName="backgroundColor"
android:duration="1000"
android:valueFrom="#000000"
android:valueTo="#FFFFFF"
android:startOffset="0"
android:repeatCount="-1"
android:repeatMode="reverse" />
</set>
在Activity java文件中,调用这个
View v = getWindow().getDecorView().findViewById(android.R.id.content);
AnimatorSet set = (AnimatorSet) AnimatorInflater.loadAnimator(this, R.animator.fade);
set.setTarget(v);
set.start();
其他回答
添加一个文件夹动画到res文件夹。(名称必须是animator)。添加一个动画资源文件。例如res/animator/fade.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<objectAnimator
android:propertyName="backgroundColor"
android:duration="1000"
android:valueFrom="#000000"
android:valueTo="#FFFFFF"
android:startOffset="0"
android:repeatCount="-1"
android:repeatMode="reverse" />
</set>
在Activity java文件中,调用这个
View v = getWindow().getDecorView().findViewById(android.R.id.content);
AnimatorSet set = (AnimatorSet) AnimatorInflater.loadAnimator(this, R.animator.fade);
set.setTarget(v);
set.start();
这里有一个很好的函数可以做到这一点:
public static void animateBetweenColors(final @NonNull View viewToAnimateItsBackground, final int colorFrom,
final int colorTo, final int durationInMs) {
final ColorDrawable colorDrawable = new ColorDrawable(durationInMs > 0 ? colorFrom : colorTo);
ViewCompat.setBackground(viewToAnimateItsBackground, colorDrawable);
if (durationInMs > 0) {
final ValueAnimator colorAnimation = ValueAnimator.ofObject(new ArgbEvaluator(), colorFrom, colorTo);
colorAnimation.addUpdateListener(animator -> {
colorDrawable.setColor((Integer) animator.getAnimatedValue());
ViewCompat.setBackground(viewToAnimateItsBackground, colorDrawable);
});
colorAnimation.setDuration(durationInMs);
colorAnimation.start();
}
}
在Kotlin中:
@JvmStatic
fun animateBetweenColors(viewToAnimateItsBackground: View, colorFrom: Int, colorTo: Int, durationInMs: Int) {
val colorDrawable = ColorDrawable(if (durationInMs > 0) colorFrom else colorTo)
ViewCompat.setBackground(viewToAnimateItsBackground, colorDrawable)
if (durationInMs > 0) {
val colorAnimation = ValueAnimator.ofObject(ArgbEvaluator(), colorFrom, colorTo)
colorAnimation.addUpdateListener { animator: ValueAnimator ->
colorDrawable.color = (animator.animatedValue as Int)
ViewCompat.setBackground(viewToAnimateItsBackground, colorDrawable)
}
colorAnimation.duration = durationInMs.toLong()
colorAnimation.start()
}
}
如果你想要这样的彩色动画,
这段代码将帮助你:
ValueAnimator anim = ValueAnimator.ofFloat(0, 1);
anim.setDuration(2000);
float[] hsv;
int runColor;
int hue = 0;
hsv = new float[3]; // Transition color
hsv[1] = 1;
hsv[2] = 1;
anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
hsv[0] = 360 * animation.getAnimatedFraction();
runColor = Color.HSVToColor(hsv);
yourView.setBackgroundColor(runColor);
}
});
anim.setRepeatCount(Animation.INFINITE);
anim.start();
罗曼米诺克回答在kotlin和作为扩展函数
fun View.colorTransition(@ColorRes startColor: Int, @ColorRes endColor: Int, duration: Long = 250L){
val colorFrom = ContextCompat.getColor(context, startColor)
val colorTo = ContextCompat.getColor(context, endColor)
val colorAnimation: ValueAnimator = ValueAnimator.ofObject(ArgbEvaluator(), colorFrom, colorTo)
colorAnimation.duration = duration
colorAnimation.addUpdateListener {
if (it.animatedValue is Int) {
val color=it.animatedValue as Int
setBackgroundColor(color)
}
}
colorAnimation.start()
}
如果你想改变当前的背景色到新的颜色,那么你可以使用这个
fun View.colorTransition(@ColorRes endColor: Int, duration: Long = 250L){
var colorFrom = Color.TRANSPARENT
if (background is ColorDrawable)
colorFrom = (background as ColorDrawable).color
val colorTo = ContextCompat.getcolor(context, endColor)
val colorAnimation: ValueAnimator = ValueAnimator.ofObject(ArgbEvaluator(), colorFrom, colorTo)
colorAnimation.duration = duration
colorAnimation.addUpdateListener {
if (it.animatedValue is Int) {
val color=it.animatedValue as Int
setBackgroundColor(color)
}
}
colorAnimation.start()
}
使用
myView.colorTransition(R.color.bg_color)
最好的方法是使用ValueAnimator和ColorUtils.blendARGB
ValueAnimator valueAnimator = ValueAnimator.ofFloat(0.0f, 1.0f);
valueAnimator.setDuration(325);
valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
float fractionAnim = (float) valueAnimator.getAnimatedValue();
view.setBackgroundColor(ColorUtils.blendARGB(Color.parseColor("#FFFFFF")
, Color.parseColor("#000000")
, fractionAnim));
}
});
valueAnimator.start();