1.添加矢量圖像
我們還需要包path
在group
因爲group
是矢量資源的一部分將被動畫。您可以爲一個組設置任何名稱。
res/drawable/ic_arrow_down.xml
<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
android:viewportWidth="306"
android:viewportHeight="306"
android:width="306dp"
android:height="306dp">
<group
android:name="arrow"
android:pivotX="153"
android:pivotY="153">
<path
android:pathData="M153 247.35L306 94.35 270.3 58.65 153 175.95 35.7 58.65 0 94.35Z"
android:fillColor="#000000" />
</group>
</vector>
res/drawable/ic_arrow_top.xml
<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
android:viewportWidth="306"
android:viewportHeight="306"
android:width="306dp"
android:height="306dp">
<group
android:name="arrow"
android:pivotX="153"
android:pivotY="153">
<path
android:pathData="M270.3 247.35L306 211.65 153 58.65 0 211.65 35.7 247.35 153 130.05Z"
android:fillColor="#000000" />
</group>
</vector>
2.添加動畫
res/animator/animation_arrow_rotation.xml
<?xml version="1.0" encoding="utf-8"?>
<objectAnimator xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="@android:integer/config_shortAnimTime"
android:propertyName="rotation"
android:valueFrom="0"
android:valueTo="180" />
3.添加動畫矢量繪圖資源
<target>
引用到group
的名字。
res/drawable/ic_animated_arrow_down.xml
<?xml version="1.0" encoding="utf-8"?>
<animated-vector xmlns:android="http://schemas.android.com/apk/res/android"
android:drawable="@drawable/ic_arrow_down">
<target
android:name="arrow"
android:animation="@animator/animation_arrow_rotation" />
</animated-vector>
res/drawable/ic_animated_arrow_up.xml
<?xml version="1.0" encoding="utf-8"?>
<animated-vector xmlns:android="http://schemas.android.com/apk/res/android"
android:drawable="@drawable/ic_arrow_up">
<target
android:name="arrow"
android:animation="@animator/animation_arrow_rotation" />
</animated-vector>
4.添加一些代碼適配器
初始化的ImageView在ParentViewHolder的繼承者:
void bind(UiModel uiModel) {
arrowImageView.setImageResource(isExpanded() ? R.drawable.ic_animated_arrow_down :
R.drawable.ic_animated_arrow_up);
// some other code
}
,並覆蓋onExpansionToggled
:
@Override
public void onExpansionToggled(boolean expanded) {
super.onExpansionToggled(expanded);
arrowImageView.setImageResource(expanded ? R.drawable.ic_animated_arrow_down :
R.drawable.ic_animated_arrow_up);
AnimatedVectorDrawableCompat drawable = (AnimatedVectorDrawableCompat) arrowImageView.getDrawable();
drawable.registerAnimationCallback(new Animatable2Compat.AnimationCallback() {
@Override
public void onAnimationEnd(Drawable ignored) {
drawable.clearAnimationCallbacks();
arrowImageView.setImageResource(expanded ? R.drawable.ic_animated_arrow_up :
R.drawable.ic_animated_arrow_down);
}
});
drawable.start();
}
順便說一句,你可以在一個XML文件中定義AnimatedVectorDrawable XML資源。細節here。