Android Filter筛选ListView并且筛选内容变色

      转载请标明原地址：http://blog.csdn.net/gaolei1201/article/details/48898831

      微信中有筛选功能，且筛选内容会变色，感觉挺酷的，研究了一下，如图

      


我首先想到的是遍历每一个数据，如果包含就把它添加到List中，然后用SpannableStringBuilder 类使筛选的内容变色。后来发现系统有一个Filter类专一用来实现筛选的，挺好。这个类的好处就是封装了异步，结构类似AsyncTask，这样不用担心数据多而阻塞主线程了。别的不多说了，上代码：

MainActivity.java

<span style="font-size:14px;">public class MainActivity extends Activity {
private Context mContext;
private ListView mListView;
private ListViewAdapter mListViewAdapter;
private ArrayList<String> mArrayList;
private EditText search_edit;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}

private void init(){
mContext=this;
mListView=(ListView) findViewById(R.id.listView);
search_edit=(EditText) findViewById(R.id.search_edit);
mArrayList=new ArrayList<String>();
mArrayList.add("张三1");
mArrayList.add("李四1");
mArrayList.add("王五1");
mArrayList.add("张三2");
mArrayList.add("李四2");
mArrayList.add("王五2");
mArrayList.add("张三3");
mArrayList.add("李四3");
mArrayList.add("王五3");
mArrayList.add("张三4");
mArrayList.add("李四4");
mArrayList.add("王五4");
mListViewAdapter=new ListViewAdapter(mContext, mArrayList);
//过滤数据
//过滤出姓名里面包含"张"的数据

mListView.setAdapter(mListViewAdapter);
search_edit.addTextChangedListener(new TextWatcher(){

@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub

}

@Override
public void beforeTextChanged(CharSequence arg0, int arg1,
int arg2, int arg3) {
// TODO Auto-generated method stub

}

@Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
mListViewAdapter.getFilter().filter(arg0);
//               也可以在这里筛选数据,但这不是异步的，有隐患，最好用系统提供的Filter类
//				 for (Iterator<String> iterator = mArrayList.iterator(); iterator
//							.hasNext();) {
//						String name = iterator.next();
//
//						if (name.contains(arg0)) {
//							mFilteredArrayList.add(name);
//						}
//				 mListViewAdapter.changeList(mFilteredArrayList);
//				 mListViewAdapter.notifyDataSetChanged();
}

});
}
public  void onDestroy(){
super.onDestroy();
ListViewAdapter.searchContent="";
}

}</span>

ListViewAdapter.java

<span style="font-size:14px;">public class ListViewAdapter extends BaseAdapter {
private NameFilter mNameFilter;
private List<String> mArrayList, copyList;
private List<String> mFilteredArrayList;
private LayoutInflater mLayoutInflater;
public static String searchContent;

public ListViewAdapter(Context context, List<String> arrayList) {
mArrayList = arrayList;
mLayoutInflater = LayoutInflater.from(context);
mFilteredArrayList = new ArrayList<String>();
//copyList是暂存原来所用的数据，当筛选内容为空时，显示所有数据，并且必须new 一个对象，
//而不能copyList=arrayList,这样的话当arrayList改变时copyList也就改变了
copyList = new ArrayList<String>();
copyList.addAll(arrayList);
}

@Override
public int getCount() {
if (mArrayList == null) {
return 0;
} else {
return (mArrayList.size());
}

}

@Override
public Object getItem(int position) {
if (mArrayList == null) {
return null;
} else {
return mArrayList.get(position);
}
}

@Override
public long getItemId(int position) {
return position;
}
public void changeList(List<String> arrayList){
mArrayList=arrayList;
}

public Filter getFilter() {
if (mNameFilter == null) {
mNameFilter = new NameFilter();
}
return mNameFilter;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
if (convertView == null) {
convertView = mLayoutInflater.inflate(R.layout.listview_items, null);
viewHolder = new ViewHolder();
viewHolder.textView = (TextView) convertView
.findViewById(R.id.textView);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}

if (mArrayList != null) {
String name = mArrayList.get(position);
viewHolder.textView.setText(name);
if (searchContent != null) {
if(name.indexOf(searchContent)!=-1){
SpannableStringBuilder style = new SpannableStringBuilder(name);
style.setSpan(
new ForegroundColorSpan(Color.parseColor("#00cc00")),
name.indexOf(searchContent),
name.indexOf(searchContent) + searchContent.length(),
Spannable.SPAN_EXCLUSIVE_INCLUSIVE); // 设置指定位置文字的颜色
viewHolder.textView.setText(style);
}
}
}

return convertView;
}

private class ViewHolder {
TextView textView;
}

// 异步过滤数据，避免数据多耗时长堵塞主线程
class NameFilter extends Filter {
// 执行筛选
@Override
protected FilterResults performFiltering(CharSequence charSequence) {
searchContent = charSequence.toString();
FilterResults filterResults = new FilterResults();
if (charSequence == null|| charSequence.length() == 0) {
mFilteredArrayList = copyList;
} else {
mFilteredArrayList.clear();
for (Iterator<String> iterator = copyList.iterator(); iterator
.hasNext();) {
String name = iterator.next();

if (name.contains(charSequence)) {
mFilteredArrayList.add(name);
}
}
}
filterResults.values = mFilteredArrayList;
return filterResults;
}

// 筛选结果
@Override
protected void publishResults(CharSequence arg0, FilterResults results) {
mArrayList = (List<String>) results.values;
if (mArrayList.size() > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}

}
}

}</span>

效果图：



                                

                代码地址，欢迎光临.......................