主要活动
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String[] answers = new String[]{"choice0","choice2","choice0","choice1","choice3","choice3"};
Question[] questions = new Question[6];
for(int i=0; i<6; i++){
questions[i] = new Question("Question"+(1+i),new String[]{"choice0","choice1","choice2","choice3"},answers[i]);
}
ListView listView = (ListView)findViewById(R.id.listQuestions);
QuestionAdapter questionAdapter = new QuestionAdapter(this, R.layout.list_item_row_qs, questions);
listView.setAdapter(questionAdapter);
}
}
适配器
public class QuestionAdapter extends ArrayAdapter {
Context context;
Question[] questions;
View view;
public QuestionAdapter(Context context, int id, Question[] questions){
super(context, id, questions);
this.context = context;
this.questions = questions;
}
private class ViewHolder{
TextView chapName;
RadioButton rb0;
RadioButton rb1;
RadioButton rb2;
RadioButton rb3;
Button button;
RadioGroup rg;
TextView hiddenAnswer;
}
@Override
public View getView(int pos, View row, ViewGroup parent){
this.view = row;
ViewHolder viewHolder = null;
if(row == null) {
LayoutInflater inflater = ((Activity)context).getLayoutInflater();
row = inflater.inflate(R.layout.list_item_row_qs, null);
viewHolder = new ViewHolder();
viewHolder.chapName=(TextView) row.findViewById(R.id.question);
viewHolder.rb0 = (RadioButton) row.findViewById(R.id.choice0);
viewHolder.rb1 = (RadioButton) row.findViewById(R.id.choice1);
viewHolder.rb2 = (RadioButton) row.findViewById(R.id.choice2);
viewHolder.rb3 = (RadioButton) row.findViewById(R.id.choice3);
viewHolder.button = (Button) row.findViewById(R.id.check);
viewHolder.hiddenAnswer = (TextView) row.findViewById(R.id.answer);
row.setTag(viewHolder);
}
else {
viewHolder = (ViewHolder)row.getTag();
}
viewHolder.chapName.setText(questions[pos].getQuestionDescr());
viewHolder.rb0.setText(questions[pos].getChoice()[0]);
viewHolder.rb1.setText(questions[pos].getChoice()[1]);
viewHolder.rb2.setText(questions[pos].getChoice()[2]);
viewHolder.rb3.setText(questions[pos].getChoice()[3]);
viewHolder.hiddenAnswer.setText(questions[pos].getAnswer());
viewHolder.button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
View rowView = (ViewGroup) v.getParent();
RadioGroup group = (RadioGroup) rowView.findViewById(R.id.rg);
int selectedId = group.getCheckedRadioButtonId();
if (selectedId == -1) {
Toast.makeText(context, "Please choose the correct option", Toast.LENGTH_LONG).show();
} else {
RadioButton radioButton = (RadioButton) group.findViewById(selectedId);
String answer = String.valueOf(((TextView) rowView.findViewById(R.id.answer)).getText());
if (radioButton.getText().equals(answer)) {
Toast.makeText(context, "Correct Answer", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(context, "Wrong Answer", Toast.LENGTH_LONG).show();
}
}
}
});
return row;
}
}
问题
列表中的第一项映射到第5项。第2项至第6项。我的意思是如果我更改第一个项目的单选按钮，也会在第5个列表项目中选择相同的单选按钮。
有什么建议吗？
是否因为回收？
我该如何解决？
我尝试保存在Question对象中并检索它。我使用pos来检索和设置。但同样的问题仍然存在。
答案 0 :(得分：0)
适配器：
public class PersonAdapter extends BaseAdapter
{
private static final int MIN_RECORDS_NUMBER = 11;
private Context _con;
private List<Person> _data;
public PersonAdapter(Context context, List<Person> data)
{
_con = context;
_data = data;
}
@Override
public int getCount()
{
return _data.size();
}
@Override
public Person getItem(int position)
{
return _data.get(position);
}
@Override
public long getItemId(int position)
{
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent)
{
Holder h = null;
if (convertView == null)
{
h = new Holder();
convertView = LayoutInflater.from(_con).inflate(R.layout.item_layout, parent, false);
h._backgroundItem = (LinearLayout) convertView.findViewById(R.id.item_layout);
h._fName = (TextView) convertView.findViewById(R.id.f_name);
h._lName = (TextView) convertView.findViewById(R.id.l_name);
h._age = (TextView) convertView.findViewById(R.id.age);
h._editBtn = (Button) convertView.findViewById(R.id.edit_btn);
convertView.setTag(h);
}
else
{
h = (Holder) convertView.getTag();
}
final Person p = getItem(position);
h._fName.setText(p._fName);
h._lName.setText(p._lName);
h._age.setText(String.valueOf(p._age));
h._backgroundItem.setActivated(p._selected);
h._editBtn.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
((MainActivity)_con).onEditClick(p._url);
}
});
convertView.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Person p = getItem(position);
Intent i = new Intent(_con,SecondActivity.class);
i.putExtra("DATA", p._fName);
_con.startActivity(i);
}
});
return convertView;
}
public void setData(List<Person> data)
{
_data = data;
notifyDataSetChanged();
}
private static class Holder
{
public LinearLayout _backgroundItem;
public TextView _fName;
public TextView _lName;
public TextView _age;
public Button _editBtn;
}
public interface IDialog
{
public void onEditClick(String url);
}
}
活动
public class MainActivity extends Activity implements IDialog
{
private ListView _listView;
private PersonAdapter _adapter;
private Button _sortBtn;
private List<Person> _data;
private int _sort;
private int _selectedItemIndex;
private Bitmap _bit;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
_listView = (ListView) findViewById(R.id.list);
_sortBtn = (Button) findViewById(R.id.sort_list_btn);
_selectedItemIndex = -1;
_sort = 1;
_data = new ArrayList<Person>();
_data.add(new Person("http://i2.cdn.turner.com/cnnnext/dam/assets/160503230552-sanders-clinton-trump-triple-composite-mullery-medium-tease.jpg","abc", "defg", 1));
_data.add(new Person("http://i2.cdn.turner.com/cnnnext/dam/assets/160503230552-sanders-clinton-trump-triple-composite-mullery-medium-tease.jpg","aaa", "defg", 12));
_data.add(new Person("http://i2.cdn.turner.com/cnnnext/dam/assets/160503230552-sanders-clinton-trump-triple-composite-mullery-medium-tease.jpg","ccc", "defg", 13));
_data.add(new Person("http://i2.cdn.turner.com/cnnnext/dam/assets/160511120611-bud-america-medium-tease.jpg","bb", "defg", 14));
_data.add(new Person("http://i2.cdn.turner.com/cnnnext/dam/assets/160511120611-bud-america-medium-tease.jpg","aa", "defg", 144));
_data.add(new Person("http://i2.cdn.turner.com/cnnnext/dam/assets/160511120611-bud-america-medium-tease.jpg","fff", "defg", 199));
// _adapter = new PersonAdapter(this, _data);
// _listView.setAdapter(_adapter);
RedirectToMainActivityTask task = new RedirectToMainActivityTask();
task.execute();
_listView.setOnItemClickListener(new OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
if(position<_data.size())
{
if(_selectedItemIndex>-1)
{
_data.get(_selectedItemIndex)._selected = false;
}
_selectedItemIndex = position;
_data.get(position)._selected = true;
_adapter.setData(_data);
}
}
});
_sortBtn.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
if(_selectedItemIndex>-1)
{
_listView.clearChoices();
String fName = _adapter.getItem(_selectedItemIndex)._fName;
Comparator<Person> sortById = Person.getComperatorByFirstName(_sort);
Collections.sort(_data, sortById);
int newSelectedItemIndex = getSelectedItemIndexByFName(fName);
_selectedItemIndex = newSelectedItemIndex;
_adapter.setData(_data);
if(newSelectedItemIndex>-1)
{
_listView.setItemChecked(newSelectedItemIndex, true);
}
_sort = -_sort;
}
else
{
Comparator<Person> sortById = Person.getComperatorByFirstName(_sort);
Collections.sort(_data, sortById);
_adapter.setData(_data);
_sort = -_sort;
}
}
});
}
private int getSelectedItemIndexByFName(String name)
{
for(int index=0;index<_data.size();index++)
{
if(_data.get(index)._fName.equals(name))
{
return index;
}
}
return -1;
}
public static class Person
{
public String _url;
public String _fName;
public String _lName;
public int _age;
public boolean _selected;
public Person(String url,String fName, String lName, int age)
{
_url = url;
_fName = fName;
_lName = lName;
_age = age;
}
public static Comparator<Person> getComperatorByFirstName(final int ascendingFlag)
{
return new Comparator<Person>()
{
@Override
public int compare(Person patient1, Person patient2)
{
return patient1._fName.compareTo(patient2._fName) * ascendingFlag;
}
};
}
}
public Bitmap getBitmapFromURL(String src) {
try
{
URL url = new URL(src);
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setInstanceFollowRedirects(true);
Bitmap image = BitmapFactory.decodeStream(httpCon.getInputStream());
return image;
}
catch (MalformedURLException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
public void onEditClick(final String url)
{
new Thread(new Runnable()
{
@Override
public void run()
{
_bit = getBitmapFromURL(url);
runOnUiThread(new Runnable()
{
@Override
public void run()
{
Dialog dialog = new Dialog(MainActivity.this);
dialog.setContentView(R.layout.custom_image);
ImageView image = (ImageView) dialog.findViewById(R.id.image);
if(_bit!=null)
{
image.setImageBitmap(_bit);
}
dialog.setTitle("This is my custom dialog box");
dialog.setCancelable(true);
//there are a lot of settings, for dialog, check them all out!
dialog.show();
}
});
}
}).start();
}
private class RedirectToMainActivityTask extends AsyncTask<Void, Void, Void>
{
protected Void doInBackground(Void... params)
{
try
{
Thread.sleep( 2 * 1000 );
}
catch ( InterruptedException e )
{
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
Intent intent = new Intent( getApplicationContext(), SecondActivity.class );
intent.addFlags( Intent.FLAG_ACTIVITY_CLEAR_TOP );
startActivity( intent );
}
}
}
我正在保存人物对象内人物视图的状态