Animation fade in and out

问题

Using this code I only have a fade in, I'm looking for how to add a fade out as well. I've added another xml called "fadeout" but I can't integrate it in my code.

ImageView imageView = (ImageView)findViewById(R.id.imageView);
Animation fadeInAnimation = AnimationUtils.loadAnimation(this, R.anim.fadein);
imageView.startAnimation(fadeInAnimation);

button1.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        imageView.startAnimation(fadeInAnimation);
    }
}

fadein.xml

<?xml version="1.0" encoding="UTF-8"?>
  <set xmlns:android="http://schemas.android.com/apk/res/android">
    <alpha android:fromAlpha="0.0" android:toAlpha="1.0" 
     android:interpolator="@android:anim/accelerate_interpolator" 
   android:duration="Your Duration(in milisecond)"
    android:repeatCount="infinite"/>
 </set>

回答1:

Here is my solution. It uses AnimatorSet. AnimationSet library was too buggy to get working. This provides seamless and infinite transitions between fade in and out.

public static void setAlphaAnimation(View v) {
    ObjectAnimator fadeOut = ObjectAnimator.ofFloat(v, "alpha",  1f, .3f);
    fadeOut.setDuration(2000);
    ObjectAnimator fadeIn = ObjectAnimator.ofFloat(v, "alpha", .3f, 1f);
    fadeIn.setDuration(2000);

    final AnimatorSet mAnimationSet = new AnimatorSet();

    mAnimationSet.play(fadeIn).after(fadeOut);

    mAnimationSet.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            super.onAnimationEnd(animation);
            mAnimationSet.start();
        }
    });
    mAnimationSet.start();
}

回答2:

This is Good Example for Fade In and Fade Out Animation with Alpha Effect

Animate Fade In Fade Out

UPDATED :

check this answer may this help you

回答3:

I´ve been working in Kotlin (recommend to everyone), so the syntax might be a bit off. What I do is to simply to call:

v.animate().alpha(0f).duration = 200

I think that, in Java, it would be the following.:

v.animate().alpha(0f).setDuration(200)

Try:

private void hide(View v, int duration) {
    v.animate().alpha(0f).setDuration(duration)
}

private void show(View v, int duration) {
    v.animate().alpha(1f).setDuration(duration)
}

回答4:

According to the documentation AnimationSet

Represents a group of Animations that should be played together. The transformation of each individual animation are composed together into a single transform. If AnimationSet sets any properties that its children also set (for example, duration or fillBefore), the values of AnimationSet override the child values

AnimationSet mAnimationSet = new AnimationSet(false); //false means don't share interpolators

Pass true if all of the animations in this set should use the interpolator associated with this AnimationSet. Pass false if each animation should use its own interpolator.

ImageView imageView= (ImageView)findViewById(R.id.imageView);
Animation fadeInAnimation = AnimationUtils.loadAnimation(this, R.anim.fade_in);
Animation fadeOutAnimation = AnimationUtils.loadAnimation(this, R.anim.fade_out);
mAnimationSet.addAnimation(fadeInAnimation);
mAnimationSet.addAnimation(fadeOutAnimation);
imageView.startAnimation(mAnimationSet);

I hope this will help you.

回答5:

we can simply use:

public void animStart(View view) {
    if(count==0){
        Log.d("count", String.valueOf(count));
        i1.animate().alpha(0f).setDuration(2000);
        i2.animate().alpha(1f).setDuration(2000);
        count =1;
    }
    else if(count==1){
        Log.d("count", String.valueOf(count));
        count =0;
        i2.animate().alpha(0f).setDuration(2000);
        i1.animate().alpha(1f).setDuration(2000);
    }
}

where i1 and i2 are defined in the onCreateView() as:

    i1 = (ImageView)findViewById(R.id.firstImage);
    i2 = (ImageView)findViewById(R.id.secondImage);

count is a class variable initilaized to 0.

The XML file is :

    <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout 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"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
        <ImageView
            android:id="@+id/secondImage"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:onClick="animStart"
            android:src="@drawable/second" />
      <ImageView
          android:id="@+id/firstImage"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"

          android:onClick="animStart"
          android:src="@drawable/first" />
    </RelativeLayout>

@drawable/first and @drawable/second are the images in the drawable folder in res.

来源：https://stackoverflow.com/questions/14156837/animation-fade-in-and-out