ListView 后台加载数据框架（查询，字母排序，更新）

た入场券 2022-08-18 05:42 117阅读 0赞

现在贴出代码和运行图： 需要代码的@ 我。

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public class MainActivity extends FragmentActivity\{

private List<City> list = null;  
private ListView mListView = null;  
private EditText mSearchEditText = null;  
private DCityListAdapter mCityListAdapter = null;  
private AbLoadDialogFragment mDialogFragment = null;  
  
  
@Override  
public void onCreate(Bundle savedInstanceState) \{  
super.onCreate(savedInstanceState);  
setContentView(R.layout.city\_list);  
  
// 获取ListView对象  
View headerView = LayoutInflater.from(this).inflate(R.layout.city\_header, null);  
mListView = (ListView) this.findViewById(R.id.listView);  
mListView.addHeaderView(headerView);  
  
DLetterFilterListView letterView = (DLetterFilterListView)this.findViewById(R.id.letterView);  
  
mSearchEditText = (EditText) this.findViewById(R.id.editText);  
  
// ListView数据  
list = new ArrayList<City>();  
  
// 使用自定义的Adapter  
mCityListAdapter = new DCityListAdapter(this, list);  
mListView.setAdapter(mCityListAdapter);  
  
// item被点击事件  
mListView.setOnItemClickListener(new OnItemClickListener() \{  
@Override  
public void onItemClick(AdapterView<?> parent, View view,  
int position, long id) \{  
  
DToastUtil.showToast(MainActivity.this, "点击"+position);  
\}  
\});  
  
//显示进度框  
mDialogFragment = DDialogUtil.showLoadDialog(this, R.drawable.ic\_load, "查询中,请等一小会");  
mDialogFragment  
.setAbDialogOnLoadListener(new AbDialogOnLoadListener() \{  
  
@Override  
public void onLoad() \{  
// 下载网络数据  
downTask();  
\}  
  
\});  
  
mSearchEditText.addTextChangedListener(new TextWatcher() \{  
  
public void onTextChanged(CharSequence s, int start, int before,  
int count) \{  
String str = mSearchEditText.getText().toString().trim();  
int length = str.length();  
if (length > 0) \{  
filterData(str);  
\} else \{  
downTask();  
\}  
\}  
  
public void beforeTextChanged(CharSequence s, int start, int count,  
int after) \{  
\}  
  
public void afterTextChanged(Editable s) \{  
  
\}  
\});  
  
\}  
  
  
public void downTask() \{  
DLogUtil.prepareLog(MainActivity.class);  
DTask mAbTask = new DTask();  
final DTaskItem item = new DTaskItem();  
item.setListener(new AbTaskListListener() \{  
@Override  
public List<?> getList() \{  
List<City> newList = null;  
try \{  
newList = filledData(getResources().getStringArray(R.array.list));  
\} catch (Exception e) \{  
\}  
return newList;  
\}  
  
@Override  
public void update(List<?> paramList) \{  
list.clear();  
list.addAll((List<City>)paramList);  
//通知Dialog  
mDialogFragment.loadFinish();  
mCityListAdapter.notifyDataSetChanged();  
\}  
  
\});  
  
mAbTask.execute(item);  
\}  
  
/\*\*  
\* 为ListView填充数据  
\* @param date  
\* @return  
\*/  
private List<City> filledData(String \[\] array)\{  
List<City> newList = new ArrayList<City>();  
//实例化汉字转拼音类  
DCharacterParser characterParser = DCharacterParser.getInstance();  
  
for(int i=0; i<array.length; i++)\{  
City city = new City();  
city.setName(array\[i\]);  
//汉字转换成拼音  
String pinyin = characterParser.getSelling(array\[i\]);  
String sortString = pinyin.substring(0, 1).toUpperCase();  
  
// 正则表达式，判断首字母是否是英文字母  
if(sortString.matches("\[A-Z\]"))\{  
city.setFirstLetter(sortString.toUpperCase());  
\}else\{  
city.setFirstLetter("\#");  
\}  
newList.add(city);  
\}  
Collections.sort(newList);  
return newList;  
  
\}  
  
/\*\*  
\* 根据输入框中的值来过滤数据并更新ListView  
\* @param filterStr  
\*/  
private void filterData(String filterStr)\{  
//实例化汉字转拼音类  
DCharacterParser characterParser = DCharacterParser.getInstance();  
List<City> filterDateList = new ArrayList<City>();  
if(!TextUtils.isEmpty(filterStr))\{  
for(City city : list)\{  
String name = city.getName();  
if(name.indexOf(filterStr) != -1 || characterParser.getSelling(name).startsWith(filterStr))\{  
filterDateList.add(city);  
\}  
\}  
\}  
  
// 根据a-z进行排序  
Collections.sort(filterDateList);  
mCityListAdapter.updateListView(filterDateList);  
\}  
  
  
  
@Override  
protected void onResume() \{  
super.onResume();  
\}  
  
public void onPause() \{  
super.onPause();  
\}

public class DCityListAdapter extends BaseAdapter implements SectionIndexer\{  
private List<City> list = null;  
private Context mContext;  
  
public DCityListAdapter(Context mContext, List<City> list) \{  
this.mContext = mContext;  
this.list = list;  
\}  
  
public int getCount() \{  
return this.list.size();  
\}  
  
public Object getItem(int position) \{  
return list.get(position);  
\}  
  
public long getItemId(int position) \{  
return position;  
\}  
  
public View getView(final int position, View view, ViewGroup arg2) \{  
ViewHolder viewHolder = null;  
final City city = list.get(position);  
if (view == null) \{  
viewHolder = new ViewHolder();  
view = LayoutInflater.from(mContext).inflate(R.layout.city\_list\_item, null);  
viewHolder.cityLetter = (TextView) view.findViewById(R.id.city\_letter);  
viewHolder.cityName = (TextView) view.findViewById(R.id.city\_name);  
view.setTag(viewHolder);  
\} else \{  
viewHolder = (ViewHolder) view.getTag();  
\}  
  
//根据position获取分类的首字母的Char ascii值  
int section = getSectionForPosition(position);  
  
//如果当前位置等于该分类首字母的Char的位置 ，则认为是第一次出现  
if(position == getPositionForSection(section))\{  
viewHolder.cityLetter.setVisibility(View.VISIBLE);  
viewHolder.cityLetter.setText(city.getFirstLetter());  
\}else\{  
viewHolder.cityLetter.setVisibility(View.GONE);  
\}  
  
viewHolder.cityName.setText(this.list.get(position).getName());  
  
return view;  
  
\}  
  
/\*\*  
\* 当ListView数据发生变化时,调用此方法来更新ListView  
\* @param list  
\*/  
public void updateListView(List<City> list)\{  
this.list.clear();  
this.list.addAll(list);  
notifyDataSetChanged();  
\}  
  
  
final static class ViewHolder \{  
TextView cityLetter;  
TextView cityName;  
\}  
  
  
/\*\*  
\* 根据ListView的当前位置获取分类的首字母的Char ascii值  
\*/  
public int getSectionForPosition(int position) \{  
return list.get(position).getFirstLetter().charAt(0);  
\}  
  
/\*\*  
\* 根据分类的首字母的Char ascii值获取其第一次出现该首字母的位置  
\*/  
public int getPositionForSection(int section) \{  
for (int i = 0; i < getCount(); i++) \{  
String sortStr = list.get(i).getFirstLetter();  
char firstChar = sortStr.toUpperCase().charAt(0);  
if (firstChar == section) \{  
return i;  
\}  
\}  
  
return -1;  
\}  
  
/\*\*  
\* 提取英文的首字母，非英文字母用\#代替。  
\*  
\* @param str  
\* @return  
\*/  
private String getAlpha(String str) \{  
String sortStr = str.trim().substring(0, 1).toUpperCase();  
// 正则表达式，判断首字母是否是英文字母  
if (sortStr.matches("\[A-Z\]")) \{  
return sortStr;  
\} else \{  
return "\#";  
\}  
\}  
  
@Override  
public Object\[\] getSections() \{  
return null;  
\}  
\}

[Center]: /images/20220731/4e317efff4e243f3849dc5d96e2643ff.png