Question

我尝试在活动开始时将内容分配给片段中的微调器。我发现首先我需要给片段充气，给布局充气，然后给视图充气，以便为它分配这段代码：

 spinner.setAdapter(adapter);

我已经查看了与此类似的问题的其他帖子，我没有得到任何运气。最终，我并没有尝试修复我的代码，而是找到一段允许我做spinner.setAdapter（adapter）的代码;没有得到NullPointerException。这个动作需要在活动开始时发生，所以基本上它需要涉及onCreate（）方法。这样做的：

 Spinner spinner = (Spinner) findViewById(R.id.spinner1);
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
            R.array.priority_array, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

将此代码放在onCreate（）中会给我一个NullPointerException，因为微调器位于片段内而不是活动中。

这是我正在尝试的当前代码无法正常工作，但同样，我正在寻找问题的解决方案，而不是我的代码：

 public class ActivityInfo extends ActionBarActivity {

Spinner b;
Myfragment fragment;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_activity_info);

    Intent intent = getIntent();
    String name = intent.getStringExtra("Name");

    FragmentManager fragmentManager = getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    fragment = new Myfragment();
    fragmentTransaction.add(R.id.RelLayout, fragment);
    fragmentTransaction.commit();

    b = (Spinner) findViewById(R.id.spinner1);
    fragment.addSpinner();





}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

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

/**
 * A placeholder fragment containing a simple view.
 */

public static class Myfragment extends Fragment {

    RelativeLayout relativeLayout; 
     View rootView;
     @Override
        public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
           relativeLayout = (RelativeLayout) rootView.findViewById(R.id.RelLayout);
        }
     @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                     Bundle savedInstanceState) {
        rootView = inflater.inflate(R.layout.fragment_activity_info, container, false);

         return rootView;
         }
     public void addSpinner()
      {

         Spinner spin = new Spinner(getActivity()); // needs activity context
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getActivity(),
                R.array.priority_array, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spin.setAdapter(adapter);
         relativeLayout.addView(spin);
      }
}

}

Answer 1

尝试这样做：

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

    View rootView = inflater.inflate(R.layout.fragment_activity_info, null);
    Spinner spinner = (Spinner) rootView.findViewById(R.id.spinner1);

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getActivity(),
        R.array.priority_array, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

    return rl;
}

如何在片段中膨胀视图？

1 个答案: