关于android：使用自定义（对象）适配器过滤ListView

Filtering ListView with custom (object) adapter

我正在尝试实现使用自定义对象适配器的ListView的筛选，但找不到任何有用的示例。所包含的代码非常简单，因此请记住，我不能使用常规的arrayadapter。我在ListView上面有一个EditText，当用户在EditText小部件中输入文本时，我希望通过EditText中写入的文本来过滤ListView。任何建议都将不胜感激！

下面是Activity类中的代码段：

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public class management_objects extends Activity {

private static List<User> UserList;
private EfficientAdapter adapter = null;
private ListView objectListView = null;
private EditText SearchText = null;

private static class EfficientAdapter extends BaseAdapter implements Filterable{
private LayoutInflater mInflater;

public EfficientAdapter(Context context) {
mInflater = LayoutInflater.from(context);
}

public int getCount() {
return UserList.size();
}

public Object getItem(int position) {
return position;
}

public long getItemId(int position) {
return position;
}

public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.imagelayout_2lines, null);
holder = new ViewHolder();
holder.text = (TextView) convertView.findViewById(R.id.managementObjectText);
holder.subtext = (TextView) convertView.findViewById(R.id.managementObjectSubText);
holder.icon = (ImageView) convertView.findViewById(R.id.managementObjectIcon);
convertView.setTag(holder);
}
else {
holder = (ViewHolder) convertView.getTag();
}

holder.text.setText(UserList.get(position).getFirstName());
holder.subtext.setText(UserList.get(position).getLastName());
holder.icon.setImageResource(R.drawable.user);

return convertView;
}

static class ViewHolder {
TextView text;
TextView subtext;
ImageView icon;
}

@Override
public Filter getFilter() {
return null;
}
}

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.adobjectlist);
Bundle extras = getIntent().getExtras();

SearchText = (EditText) findViewById(R.id.SearchBox);
SearchText.addTextChangedListener(filterTextWatcher);

objectListView = (ListView) findViewById(R.id.ObjectList);
objectListView.setOnItemClickListener(Item_Click);
adapter = new EfficientAdapter(this);
ComputerName = extras.getString("COMPUTER_NAME");

//Get User list from webservice
ShowUsers();
}

这是用户类：

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public class User {
private int UserId;
private String FirstName;
private String LastName;

public int getUserId() {
return UserId;
}
public void setUserId(int UserId) {
this.UserId = UserId;
}
public String getFirstName() {
return FirstName;
}
public void setFirstName(String FirstName) {
this.FirstName = FirstName;
}
public String getLastName() {
return LastName;
}
public void setLastName(String LastName) {
this.LastName = LastName;
}
}

你需要做一些事情：

1)在活动中，在包含用户输入值的editText上注册文本更改侦听器：

mSearchValue.addTextChangedListener(searchTextWatcher);

2)创建SearchTextWatcher并让它执行以下操作：

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private TextWatcher searchTextWatcher = new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// ignore
}

@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// ignore
}

@Override
public void afterTextChanged(Editable s) {
Log.d(Constants.TAG,"*** Search value changed:" + s.toString());
adapter.getFilter().filter(s.toString());
}
};

3)重写自定义适配器中的getfilter()，让它过滤结果，并通知ListView数据集已更改。

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@Override
public Filter getFilter() {
return new Filter() {
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
Log.d(Constants.TAG,"**** PUBLISHING RESULTS for:" + constraint);
myData = (List<MyDataType>) results.values;
MyCustomAdapter.this.notifyDataSetChanged();
}

@Override
protected FilterResults performFiltering(CharSequence constraint) {
Log.d(Constants.TAG,"**** PERFORM FILTERING for:" + constraint);
List<MyDataType> filteredResults = getFilteredResults(constraint);

FilterResults results = new FilterResults();
results.values = filteredResults;

return results;
}
};
}