安卓 java替换列表内容或替换引用值本身

Question

我有一个用于Android中ListView适配器的列表

大多数情况下，列表用于读取，但有时需要替换所有列表内容

下面哪种类型的代码（replaceListA、replaceListB）是首选代码？还是用另一种方法来取代名单

提前谢谢你

private ArrayList<Model> list = new ArrayList<Model>();

public synchronized void replaceListA(List newList) {
            list.clear();
            list.addAll(newList);
}

public synchronized void replaceListB(List newList) {
    list = newList;
}

Answer 1

第二种是首选。它在O（1）时间内运行，另一个在O（n）时间内运行。之后一定要给notifyDataSetChanged打电话

Answer 2

见this answer

It's hard to know without a benchmark, but if you have lots of items in your ArrayList and the average size is lower, it might be faster to make a new ArrayList.