在iOS中，有一个非常简单和强大的工具来动画添加和删除UITableView行，这是一个来自youtube视频的剪辑，显示默认动画。注意周围的行如何折叠到已删除的行上。这个动画帮助用户跟踪列表中发生了什么变化，以及当数据发生变化时他们正在查看列表中的哪个位置。
Since I've been developing on Android I've found no equivalent facility to animate individual rows in a TableView. Calling notifyDataSetChanged() on my Adapter causes the ListView to immediately update its content with new information. I'd like to show a simple animation of a new row pushing in or sliding out when the data changes, but I can't find any documented way to do this. It looks like LayoutAnimationController might hold a key to getting this to work, but when I set a LayoutAnimationController on my ListView (similar to ApiDemo's LayoutAnimation2) and remove elements from my adapter after the list has displayed, the elements disappear immediately instead of getting animated out.
我还尝试了如下方法，在移除单个项目时将其动画化:
@Override
protected void onListItemClick(ListView l, View v, final int position, long id) {
Animation animation = new ScaleAnimation(1, 1, 1, 0);
animation.setDuration(100);
getListView().getChildAt(position).startAnimation(animation);
l.postDelayed(new Runnable() {
public void run() {
mStringList.remove(position);
mAdapter.notifyDataSetChanged();
}
}, 100);
}
但是，动画行周围的行不会移动位置，直到调用notifyDataSetChanged()时它们跳转到新位置。一旦元素被放置，ListView似乎不会更新它的布局。
虽然写我自己的ListView的实现/分支已经越过我的脑海，这似乎不应该是那么困难的事情。
谢谢!
只是分享另一种方法:
首先设置列表视图的android:animateLayoutChanges为true:
<ListView
android:id="@+id/items_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true"/>
然后我使用一个处理程序来添加项目，并延迟更新listview:
Handler mHandler = new Handler();
//delay in milliseconds
private int mInitialDelay = 1000;
private final int DELAY_OFFSET = 1000;
public void addItem(final Integer item) {
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
new Thread(new Runnable() {
@Override
public void run() {
mDataSet.add(item);
runOnUiThread(new Runnable() {
@Override
public void run() {
mAdapter.notifyDataSetChanged();
}
});
}
}).start();
}
}, mInitialDelay);
mInitialDelay += DELAY_OFFSET;
}
我用另一种方法来做而不需要操作列表视图。不幸的是，常规的Android动画似乎操纵行内容，但实际上是无效的缩小视图。所以，首先考虑这个处理程序:
private Handler handler = new Handler() {
@Override
public void handleMessage(Message message) {
Bundle bundle = message.getData();
View view = listView.getChildAt(bundle.getInt("viewPosition") -
listView.getFirstVisiblePosition());
int heightToSet;
if(!bundle.containsKey("viewHeight")) {
Rect rect = new Rect();
view.getDrawingRect(rect);
heightToSet = rect.height() - 1;
} else {
heightToSet = bundle.getInt("viewHeight");
}
setViewHeight(view, heightToSet);
if(heightToSet == 1)
return;
Message nextMessage = obtainMessage();
bundle.putInt("viewHeight", (heightToSet - 5 > 0) ? heightToSet - 5 : 1);
nextMessage.setData(bundle);
sendMessage(nextMessage);
}
将这个集合添加到您的List适配器:
private Collection<Integer> disabledViews = new ArrayList<Integer>();
并添加
public boolean isEnabled(int position) {
return !disabledViews.contains(position);
}
接下来，无论你想要隐藏一行的地方，添加这个:
Message message = handler.obtainMessage();
Bundle bundle = new Bundle();
bundle.putInt("viewPosition", listView.getPositionForView(view));
message.setData(bundle);
handler.sendMessage(message);
disabledViews.add(listView.getPositionForView(view));
就是这样!你可以通过改变一次缩小高度的像素数来改变动画的速度。不是很复杂，但很管用!
