Question

我正在尝试去一个特定的片段，我在Activity中初始化它。但我的屏幕上没有任何错误，但在我的设备上，我的应用程序停止运行，他没有进入Fragment。可能是什么问题？ Thanx为你提供帮助。您可以在下面找到我的代码：

public class SubCatActivity extends Activity {
int hoofdCat;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_subcat);
    if (savedInstanceState == null) {
        getFragmentManager().beginTransaction()
                .replace(R.id.container, new SubCatFragment())
                .commit();
    }
    hoofdCat = Integer.parseInt(getIntent().getStringExtra("hoofdCat"));
}

public int getHoofdCat(){return hoofdCat;}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.info, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

我的片段：

public class SubCatFragment extends Fragment implements SubCatFragmentInteractionListener {

private SubCatFragmentInteractionListener mListener;

public SubCatFragment(){

}

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

    View rootView = inflater.inflate(R.layout.fragment_subcat, container, false);

    ListView lstSubcat = (ListView) rootView.findViewById(R.id.lvSubcat);

    ArrayList<String> subcat = new ArrayList<String>();
    SubCatActivity activity = (SubCatActivity)getActivity();
    int hoofdcat =activity.getHoofdCat();
    DBAdapter db = new DBAdapter(getActivity().getBaseContext());
    db.open();
    Cursor c = db.getAllSubcat(hoofdcat);
    if(c.moveToFirst())
    {
        do{
            subcat.add(c.getString(1));
        }while (c.moveToNext());
    }
    db.close();
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
            android.R.layout.simple_list_item_1, subcat);
    lstSubcat.setAdapter(adapter);

    lstSubcat.setOnItemClickListener(lstSubcatItemClickListener);
    return rootView;
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
        mListener = (SubCatFragmentInteractionListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement HoofdCatFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

private ListView.OnItemClickListener lstSubcatItemClickListener = new ListView.OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int pos, long id) {
        //mListener.showSubCatActivity(pos+1);
    }
};

}

Answer 1

使用FragmentActivity。

public class SubCatActivity extends FragmentActivity{
....
}

FragmentActivity

Answer 2

在onPostCreate中替换或添加片段，而不是onCreate。

Android不会加载片段（使用Activity）。为什么？

2 个答案: