动画显示，旋转和消失

Question

I want to do a multiple animations on my image (appear -> rotate -> disappear). I've got this code:

fade_in.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:fillAfter="true"
android:shareInterpolator="false" >

<alpha
    android:duration="1"
    android:fromAlpha="0"
    android:toAlpha="100" />

</set>

fade_out.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:fillAfter="true"
android:shareInterpolator="false" >

<alpha
    android:duration="1"
    android:fromAlpha="100"
    android:toAlpha="0" />

</set>

image_rotate.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:fillAfter="true"
android:shareInterpolator="false" >

<rotate
    android:duration="2500"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toDegrees="120" />

</set>

Also in my java code:

animRotate= AnimationUtils.loadAnimation(context, R.anim.image_rotate);
animRotate.setDuration((long) duration);
fade_in = AnimationUtils.loadAnimation(context, R.anim.fade_in);
fade_out = AnimationUtils.loadAnimation(context, R.anim.fade_out);

AnimationSet s = new AnimationSet(false);
s.addAnimation(fade_in);
s.addAnimation(animRotate);
s.addAnimation(fade_out);

image.startAnimation(s);

but unfortunately it doesn't work correctly...

Answer 1

you have severals errors in your animation xml files:

• the duration property is in milliseconds, so 1ms is way too short for a noticeable fade in/fade out animation
• the alpha property is a float between 0 et 1, 100 is way too much.
• you don't need a set in your xml files if there is only one animation : just add the alpha or rotate tag as a root

So, you should have now these files:

fade_in.xml

<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="1000"
    android:fromAlpha="0"
    android:toAlpha="1" />

fade_out.xml

<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="1000"
    android:fromAlpha="1"
    android:toAlpha="0" />

image_rotate.xml

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="2500"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toDegrees="120" />

Then, in your code, you need a add an offset between each animation. Otherwise, all the animations will be triggered at the same time. Moreover, the flag must be set on the root animation object (here, your AnimationSet )

Animation animRotate= AnimationUtils.loadAnimation(context, R.anim.image_rotate);
Animation fade_in = AnimationUtils.loadAnimation(context, R.anim.fade_in);
Animation fade_out = AnimationUtils.loadAnimation(context, R.anim.fade_out);

AnimationSet s = new AnimationSet(false);
s.addAnimation(fade_in);

animRotate.setDuration((long) duration);
animRotate.setStartOffset(fade_in.getDuration());
s.addAnimation(animRotate);

fade_out.setStartOffset(fade_in.getDuration() + animRotate.getDuration());
s.addAnimation(fade_out);

s.setFillAfter(true);

image.startAnimation(s);