将数据从Activity传递到Fragment（通过访问来自fragment的Activity），从而给出Class Cast Exception

Question

There are so many ways but i am using this one:

Activity:

public class Main2Activity extends AppCompatActivity{

private String myString = "hello";

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

public String getMyData() {
    return myString;
}
} 

Fragment:

public class MyFragment extends android.support.v4.app.Fragment{

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

    Main2Activity activity = (Main2Activity ) getActivity();
    String myDataFromActivity = activity.getMyData();
    return view;
}
}

BUT its giving me class cast exception:

 java.lang.ClassCastException: com.example.dev03.xyz.Activities.MainActivity cannot be cast to com.example.dev03.xyz.Fragments.MyActivity

java.lang.ClassCastException: com.example.dev03.xyz.Fragments.MainActivity cannot be cast to com.example.dev03.xyz.Fragments.Main2Activity

-- Package is same

Thanks

Answer 1

You are opening your fragment in MainActivity and want to cast in MyActivity. That's why it is showing ClassCastException

Answer 2

Create an object of MainActivity2 and simply access your method:

  MainActivity2 mn2=new ManiActivity2();
  mn2.getMyData();

Answer 3

从android.app.Fragment更改为support.v4.app.Fragment。

Answer 4

In your Activity

    Bundle bundle = new Bundle();
bundle.putString("name", "StackOverFlow");
// set Fragmentclass Arguments
Fragmentclass stackOverflow = new Fragmentclass();
stackOverflow.setArguments(bundle);

In Fragments > onCreateView Method.

String strName = getArguments().getString("name");