Question

我有第一个片段和第二个片段，我希望从第二个片段在frist fragent中使用接口回调制作一些东西，但我发现此错误

java.lang.NullPointerException: Attempt to invoke interface method

接口

public interface MyProfileCallback

 {
    void callbackCall(Context con);

 }

第一个片段：

  public class firstfragment extends Fragment implements MyProfileCallback
  {

public firstfragment()
{
    // Required empty public constructor
}

@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState)
{
    View rootview = inflater.inflate(R.layout.fisrt, container, false);

    /
  ...
    /       
    }
    @Override
   public void callbackCall(Context con)
   {

    Toast.makeText(getActivity(), "calllllllllll baaaaaaaaaaaaack",
            Toast.LENGTH_SHORT).show();
  }
 }

第二个片段：

 public class secondfragment extends Fragment
 {

  MyProfileCallback mcallback;

  public secondfragment()
  {
    // Required empty public constructor
  }


    @Override
   public View onCreateView(LayoutInflater inflater, ViewGroup container,     

Bundle savedInstanceState)
{
    View rootview = inflater.inflate(R.layout.second, container, false);


    mcallback.callbackCall(getContext());


    return rootview;
}

Answer 1

在第二个片段中添加此内容，

mcallback=refernce of your First Frgament;

并调用此方法：

 mcallback.callbackCall(getContext());

回调两个片段之间的函数？

1 个答案: