制作稀疏数组<>包含的数组列表<String>

Question

我需要做一个数组列表，我的想法是:

 Map<Integer, ArrayList<String>> SentReportMap=new HashMap<Integer, ArrayList<String>>();

说明:

 Use new SparseArray<ArrayList<String>>(...) instead for better performance

所以，我试着这样做:

 SparseArray<String> SentReportMap = new SparseArray<String>();
 ArrayList<String> items=new ArrayList<String>();
 items.add(array.getProperty("To").toString());
 items.add(array.getProperty("Date").toString());
 SentReportMap.put(1, items);

，但是如果用数据填充这个数组，返回这个错误:

The method put(int, String) in the type SparseArray<String> is not applicable for the arguments (int, ArrayList<String>)

或

The method put(int, String) in the type SparseArray<String> is not applicable for the arguments (ArrayList<String>, int)

哪里是错误的，什么是更好的解决方案，使数组的数组列表!?

Answer 1

SentReportMap的声明是错误的，它应该是:

SparseArray<ArrayList<String>> SentReportMap = new SparseArray<ArrayList<String>>();

Answer 2

change

 SparseArray<String> SentReportMap = new SparseArray<String>();

SparseArray<ArrayList<String>> SentReportMap = new SparseArray<ArrayList<String>>();

SparseArray是更好的解决方案，因为:

SparseArrays map integers to Objects. Unlike a normal array of Objects, there can be gaps in the indices. It is intended to be more memory efficient than using a HashMap to map Integers to Objects, both because it avoids auto-boxing keys and its data structure doesn't rely on an extra entry object for each mapping.

点击此链接获取更多信息。

http://developer.android.com/reference/android/util/SparseArray.html