CODEWITHSUNDEEP
javaandroidandroid-fragments
Minkoo
Minkoo

Reputation: 439

Pass data from Activity to Fragment Class Cast Exception

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

Activity:(Main2Activity)

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;
}
}

Main Activity:

    public class MainActivity extends AppCompatActivity {

   -------
    @Override
    protected void onCreate(Bundle savedInstanceState) {
     }
      ---
     private void setupViewPager(ViewPager viewPager) {

    Adapter adapter = new Adapter(getSupportFragmentManager());
    adapter.addFragment(new MyFragment(), "MyFragment");

    viewPager.setAdapter(adapter);
    }

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

Upvotes: 2

Views: 825

Answers (7)

Minkoo
Minkoo

Reputation: 439

I searched for a whole day , Finally i got the perfect solution: If anyone having the same problem you can follow this answer.

NO need to create any method in Main2Activity and call it from MyFragment. Best practice is , use startActivityForResult and onActivityResult. Here is the code:

Fragment:

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

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

   Intent i = new Intent(getActivity(), Main2Activity.class);
            startActivityForResult(i, 1);
  }
  }

Main2Activity:

  public class Main2Activity extends AppCompatActivity{

 private String myString = "hello";

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

    Intent returnIntent = new Intent();
            returnIntent.putExtra("result", selectedPath1);
            returnIntent.putExtra("result2", selectedPath2);
            setResult(Activity.RESULT_OK, returnIntent);
            finish();

}  
}

Simple.

Upvotes: 1

G Setia
G Setia

Reputation: 61

Create an object of MainActivity2 and simply call your getMyData method from Fragment Class

Upvotes: 1

Masum
Masum

Reputation: 4959

If you want to done this work you must have to keep your myFragment into Main2Activity instead of MainActivity.

Upvotes: 1

Android Geek
Android Geek

Reputation: 9225

Create an object of MainActivity2 and access the method as follow: 

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

Upvotes: 1

Sreehari
Sreehari

Reputation: 5655

In your Activity, do the following

MyFragment fragmentObj=new MyFragment();
Bundle args = new Bundle();
args.putString("Data_Key", string_value);
fragmentObj.setArguments(args);

Now add this Fragment to stack using FragmentTransaction.

After this, in your Fragment class's onCreateView do the following

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

View rootView = inflater.inflate(R.layout.fragment_xml_view, container, false);
  if (getArguments() != null) 
  {
      String valueReceived = getArguments().getString("Data_Key");
  }
 return rootView;
}

Upvotes: 1

Atiq
Atiq

Reputation: 14825

Try making your getMyData() static

public static String getMyData() {
return myString;

}

and then access it in fragment like

Main2Activity.getMyData();

Upvotes: 1

TmCrafz
TmCrafz

Reputation: 184

You create your Fragment in MainActivity and it belongs to it, so you get MainActivity instead of Main2Activity when you use getAcitvity().

Upvotes: 3

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