Am I creating my custom ArrayAdapter correctly?
My ListView populates correctly, but for some reason adding and removing is quirky and does not work properly! Am I doing something wrong?
Set things up in OnC开发者_开发问答reate()
listView = (ListView) findViewById(R.id.ListView);
registerForContextMenu(listView);
deserializeQuotes();
if(quotes == null || quotes.size() == 0){
quotes = new ArrayList<Quote>();
//populateDefaultQuotes();
//serializeQuotes();
//getQuotesFromYQL();
}
this.quotesAdapter = new QuoteAdapter(this, R.layout.mainrow, quotes);
listView.setAdapter(this.quotesAdapter);
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
deserializeQuotes();
Quote myQuote = quotes.get(position);
Toast toast = Toast.makeText(getApplicationContext(), myQuote.getName(), Toast.LENGTH_SHORT);
toast.show();
}
});
Quote Adapter Private Class
private class QuoteAdapter extends ArrayAdapter<Quote> {
private ArrayList<Quote> items;
public QuoteAdapter(Context context, int textViewResourceId,
ArrayList<Quote> items) {
super(context, textViewResourceId, items);
this.items = items;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.mainrow, null);
}
Quote q = items.get(position);
if (q != null) {
TextView nameText = (TextView) v.findViewById(R.id.nameText);
TextView priceText = (TextView) v.findViewById(R.id.priceText);
TextView changeText = (TextView) v.findViewById(R.id.changeText);
if (nameText != null) {
nameText.setText(q.getSymbol());
}
if (priceText != null) {
priceText.setText(q.getLastTradePriceOnly());
}
if (changeText != null) {
changeText.setText(q.getChange());
}
}
return v;
}
}
Remove an item from the list (THIS DOESNT WORK, DOES NOTHING)
@Override
public boolean onContextItemSelected(MenuItem item) {
if(item.getTitle()=="Remove"){
deserializeQuotes();
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
quotesAdapter.remove(quotes.get(info.position));
quotesAdapter.notifyDataSetChanged();
serializeQuotes();
}
else {
return false;
}
return true;
}
Add an item to the list (THIS WORKS)
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
deserializeQuotes();
this.quotesAdapter = new QuoteAdapter(this, R.layout.mainrow, quotes);
quotesAdapter.notifyDataSetChanged();
listView.setAdapter(quotesAdapter);
}
}
Here is how I serialize and deserialize
private void serializeQuotes(){
FileOutputStream fos;
try {
fos = openFileOutput(Constants.FILENAME, Context.MODE_PRIVATE);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(quotes);
oos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e){
e.printStackTrace();
}
}
@SuppressWarnings("unchecked")
private void deserializeQuotes(){
try{
FileInputStream fis = openFileInput(Constants.FILENAME);
ObjectInputStream ois = new ObjectInputStream(fis);
quotes = (ArrayList<Quote>) ois.readObject();
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e){
e.printStackTrace();
}catch(ClassNotFoundException e){
e.printStackTrace();
}
}
The code seems to be alright. Can you try using this in your remove?:
if("Remove".equals(item.getTitle())) {
//....
}
Edit:
I just noticed you are de-serializing "Quote" objects by calling deserializeQuotes()
. Have you overridden the boolean equals(Object)
method of Quote object? When you de-serialize, the object created are not the "same", i.e. they are new objects altogether and if you haven't overridden the equals method:
quotesAdapter.remove(quotes.get(info.position));
will fail because it won't find any Quote object to remove in the list.
Can you check that?
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