Android 动画仅当 ListView 向下滚动时

Question

我在布局中有一个 ListView，只有当列表向下滚动时，我才需要应用动画（从下到上出现）。

我该怎么做？

请帮我。

Answer 1

希望这会帮助你。谷歌加动画

up_from_bottom.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
     android:shareInterpolator="@android:anim/decelerate_interpolator">
    <translate
        android:fromXDelta="0%" android:toXDelta="0%"
        android:fromYDelta="100%" android:toYDelta="0%"
        android:duration="400" />
</set>

down_from_top.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
     android:shareInterpolator="@android:anim/decelerate_interpolator">
    <translate
        android:fromXDelta="0%" android:toXDelta="0%"
        android:fromYDelta="-100%" android:toYDelta="0%"
        android:duration="400" />
</set>

代码：

private int lastPosition = -1;

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    //Load your view, populate it, etc...
    View view = ...;

    Animation animation = AnimationUtils.loadAnimation(getContext(), (position > lastPosition) ? R.anim.up_from_bottom : R.anim.down_from_top);
    view.startAnimation(animation);
    lastPosition = position;

    return view;
}