安卓按字母顺序对ListView进行排序
安卓按字母顺序对ListView进行排序
提问于 2013-10-30 16:00:46
所以我尝试为ListView排序一个简单的ArrayAdapter。这是我尝试过的：
ListView lv;
String[] months = {
"January",
"February",
"March",
"April",
"May",
"June",
"July",
"August",
"September",
"October",
"November",
"December"
};
ArrayAdapter<String> adapter;
ArrayList<String> list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv = (ListView) findViewById(R.id.listView1);
lv.setFastScrollEnabled(true);
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, months);
lv.setAdapter(adapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// TODO Auto-generated method stub
switch (item.getItemId()) {
case R.id.sortasc:
list = new ArrayList<String>(Arrays.asList(months));
Collections.sort(list);
for (int i = 0; i < list.size(); i++) {
System.out.println(list.get(i));
}
adapter.clear();
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, list);
adapter.notifyDataSetChanged();
return true;
case R.id.sortdesc:
return true;
default:
return super.onOptionsItemSelected(item);
}
}但是我得到了UnsupportedOperationException，这有什么问题吗？我真的需要帮助。提前感谢！
回答 7
Stack Overflow用户
回答已采纳
发布于 2013-10-30 16:06:25
在对项目进行排序后，您没有调用setAdapter(适配器)。
使用方法如下
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, list);
lv.setAdapter(adapter);
adapter.notifyDataSetChanged();而不是
adapter.clear(); // Useless
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, list);
adapter.notifyDataSetChanged();Stack Overflow用户
发布于 2013-10-30 16:09:01
这是诀窍..。
private void sortAscending () {
List<String> sortedMonthsList = Arrays.asList(months);
Collections.sort(sortedMonthsList);
months = (String[]) sortedMonthsList.toArray();
}对于sortAscending，调用
sortAscending();
adapter.notifyDatasetChanged();类似地，您也可以实现用于降序排序的自定义Comparator ...
希望这能有所帮助...：)
Stack Overflow用户
发布于 2013-10-30 16:14:04
Comparator<String> ALPHABETICAL_ORDER1 = new Comparator<String>() {
public int compare(String object1, String object2) {
int res = String.CASE_INSENSITIVE_ORDER.compare(object1.toString(), object2.toString());
return res;
}
};
Collections.sort(your array name, ALPHABETICAL_ORDER1);页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/19676781
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