Question

我在setOnItemSelectedListener：

中遇到此错误

AdapterView类型中的方法setOnItemSelectedListener（AdapterView.OnItemSelectedListener）不适用于参数（FragmentMain）＆＃34;

片段类：

public class FragmentMain extends Fragment  {

private Spinner countriesSpinner;
private Activity rootView;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState){
     View rootView =inflater.inflate(R.layout.activity_main, container, false);
     return rootView;
}
@Override
public void onStart() {
    super.onStart();

    addItemsOnSpinner();
}
public void addItemsOnSpinner() {

    countriesSpinner = (Spinner) rootView.findViewById(R.id.team_list_spinner);
    countriesSpinner.setOnItemSelectedListener(new  CustomOnItemSelectedListener ()) ;

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getActivity(),
            R.array.team_list, android.R.layout.simple_spinner_item);

    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    countriesSpinner.setAdapter(adapter);

    countriesSpinner.setOnItemSelectedListener(this);

    }

public class CustomOnItemSelectedListener extends Activity implements
OnItemSelectedListener {

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int pos,
            long id)  {
        // TODO Auto-generated method stub
        if (parent.getItemAtPosition(pos).toString()
                .equals("San Antonio Spurs")) {
            Intent i = new Intent(getApplicationContext(), Spurs_games.class);
            startActivity(i);
            finish();}
        if (parent.getItemAtPosition(pos).toString()
                .equals("Los Angeles Lakers")) {
            Intent i = new Intent(getApplicationContext(), Lakers_games.class);
            startActivity(i);
            finish();}
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }

}

public void onItemSelected(AdapterView<?> parent, View view, int pos,
        long id) {
    if (parent.getItemAtPosition(pos).toString()
            .equals("San Antonio Spurs")) {
        Intent i = new Intent(getActivity(), Spurs_games.class);
        startActivity(i);
        finish();}
    if (parent.getItemAtPosition(pos).toString()
            .equals("Los Angeles Lakers")) {
        Intent i = new Intent(getActivity(), Lakers_games.class);
        startActivity(i);
        finish();}
}

private void finish() {
    // TODO Auto-generated method stub

}
public void onNothingSelected(AdapterView<?> arg0) {
    // TODO Auto-generated method stub

}
}

这是我在这里的第一篇文章，请原谅/纠正我请。对不起我的英文..

Answer 1

setOnItemSelectedListener

如果您想在片段内的微调器上使用侦听器

，则必须在FragmentMain内未在Activity内实施

在FragmentMain onCreateView

中

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
...
}

把这段代码

countriesSpinner = (Spinner) rootView.findViewById(R.id.team_list_spinner);
countriesSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view,
                                       int position, long id) {
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

Answer 2

问题是这一行：

countriesSpinner.setOnItemSelectedListener(this);

因为＆＃34;这个＆＃34;在你的情况下引用Fragment，但是你应该传入一个OnItemSelectedListener对象。

对于听众的工作方式似乎也存在很多困惑。您可能希望在Fragment中实现OnItemSelectedListener，而不是创建CustomOnItemSelectedListener Activity。或者创建一个匿名的OnItemSelectedListener：

    countriesSpinner.setOnItemSelectedListener(new OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> parent, View view,
                int position, long id) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
            // TODO Auto-generated method stub

        }
    });

Fragment中用于微调器的setOnItemSelectedListener

2 个答案: