通过自定义ArrayAdapter中的输入过滤数据显示空项目 [英] Filter data by input in custom ArrayAdapter displays empty items
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问题描述
我实现了EditText小部件，以使用自定义ArrayAdapter过滤ListFragment中的项目.
I implemented EditText widget to filter items in ListFragment using custom ArrayAdapter.
它工作正常，但是过滤后的列表包含EMPTY项目以及过滤后的项目.
我发现我应该在重新填充适配器之前先清除适配器，对吧?
I found that i should clear the adapter before to repopulate it, right?
可能是
adapter.clear();
listview.getAdapter().notifyDataSetChanged();
无论如何，我找不到可行的解决方案.
Anyway I cannot find working solution.
请问有任何解决此错误的线索吗?
Any clue to fix this bug, please?
public class CustomListAdapter extends ArrayAdapter<UnitView> {
private static final String TAG = "FRAGMENT TWO";
private final Activity context;
private final UnitView[] dataSource;
private UnitView[] unitViews;
public CustomListAdapter(Activity context, UnitView[] units) {
super(context, R.layout.unit, units);
this.context = context;
this.unitViews = units;
this.dataSource = units;
}
public View getView(int position,View view,ViewGroup parent) {
view = null;
try
{
if (view == null)
{
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.listview_item, null);
UnitView uv = unitViews[position];
view.setTag(uv);
TextView textViewTypeName = (TextView) view.findViewById(R.id.textViewTypeName);
textViewTypeName.setText(uv.getDeviceTypeName());
// Code to populate widgets ....
}
}
catch (Exception ex)
{
Log.d(TAG, ex.getMessage());
}
return view;
};
// Filter input data in ListFragment
public void filter(String charText) {
try
{
charText = charText.toLowerCase(Locale.getDefault());
unitViews = new UnitView[dataSource.length];
if (charText.length() == 0) {
unitViews = Arrays.copyOf(this.dataSource, this.dataSource.length);
}
else
{
List<UnitView> result = new ArrayList<UnitView>();
for (UnitView uv : dataSource)
{
if (uv.getNumber().toLowerCase(Locale.getDefault()).contains(charText))
{
result.add(uv);
}
}
if(result.size() > 0)
{
unitViews = result.toArray(new UnitView[result.size()]);
}
}
notifyDataSetChanged();
}
catch (Exception ex)
{
Log.d(TAG, ex.getMessage());
}
}
public static boolean isBlank(String value) {
return (value == null || value.equals("") || value.equals("null") || value.trim().equals(""));
}
}
FragmentTwo.java
protected void onPostExecute(String s) {
super.onPostExecute(s);
try {
Gson gson = new Gson();
unitViews = gson.fromJson(s, UnitView[].class);
if (unitViews.length > 0) {
ArrayList<String> names = new ArrayList<String>();
for (int i = 0; i < unitViews.length; i++) {
String name = unitViews[i].getName();
names.add(name);
}
String[] values = names.toArray(new String[unitViews.length]);
adapter = new CustomListAdapter(getActivity(), unitViews);
setListAdapter(adapter);
// Locate the EditText in listview_main.xml
editSearch = (EditText)getActivity().findViewById(R.id.editSearch);
// Capture Text in EditText
editSearch.addTextChangedListener(new TextWatcher() {
@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
String text = editSearch.getText().toString().toLowerCase(Locale.getDefault());
adapter.filter(text);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
}
@Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
}
});
Log.d(TAG, s);
}
}
catch (Exception ex)
{
Log.e(TAG, "Error: ", ex);
}
}
推荐答案
好，我找到了解决方案，方法是将过滤器代码重新定位到onPostExecute并重新初始化适配器.
Ok, I found solution by relocating filter code to onPostExecute and re-initializing adapter.
protected void onPostExecute(String s) {
super.onPostExecute(s);
try {
Gson gson = new Gson();
unitViews = gson.fromJson(s, UnitView[].class);
if (unitViews.length > 0) {
ArrayList<String> names = new ArrayList<String>();
for (int i = 0; i < unitViews.length; i++) {
String name = unitViews[i].getName();
names.add(name);
}
String[] values = names.toArray(new String[unitViews.length]);
adapter = new CustomListAdapter(getActivity(), unitViews);
setListAdapter(adapter);
// Locate the EditText in listview_main.xml
editSearch = (EditText)getActivity().findViewById(R.id.editSearch);
// Capture Text in EditText
editSearch.addTextChangedListener(new TextWatcher() {
@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
String text = editSearch.getText().toString().toLowerCase(Locale.getDefault());
// adapter.filter(text);
try
{
text = text.toLowerCase(Locale.getDefault());
UnitView[] resultUnitViews = new UnitView[0];
if (text.length() == 0) {
resultUnitViews = Arrays.copyOf(unitViews, unitViews.length);
}
else
{
List<UnitView> result = new ArrayList<UnitView>();
for (UnitView uv : unitViews)
{
if (uv.getNumber().toLowerCase(Locale.getDefault()).contains(text))
{
result.add(uv);
}
}
if(result.size() > 0)
{
resultUnitViews = result.toArray(new UnitView[result.size()]);
adapter = new CustomListAdapter(getActivity(), resultUnitViews);
setListAdapter(adapter);
}
}
}
catch (Exception ex)
{
Log.d(TAG, ex.getMessage());
}
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
}
@Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
}
});
Log.d(TAG, s);
}
}
catch (Exception ex)
{
Log.e(TAG, "Error: ", ex);
}
}
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