在Android中从Fragment刷新活动

Question

I have followed this . I want to refresh the Activity from Fragment . I have back button in toolbar for Fragment to Activity communication.

Here is my code for button listener and refresh the activity. I include this in fragment class:

final Toolbar toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
    toolbar.setNavigationIcon(R.drawable.ic_arrow_back_black_24dp);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            new Handler().post(new Runnable() {

                @Override
                public void run()
                {
                    Intent intent = getActivity().getIntent();
                    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK
                            | Intent.FLAG_ACTIVITY_NO_ANIMATION);
                    getActivity().overridePendingTransition(0, 0);
                    getActivity().finish();

                    getActivity().overridePendingTransition(0, 0);
                    startActivity(intent);
                }
            });
        }
    });

This works fine, but it completly reload the app. What can be done here, so that I can avoid the reload operation and just refresh the activity?

Answer 1

Use callback(interface) to communicate with activity from fragment and don't use Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK because it will clear your stack.

ex.

Fragment{
CallBack callback;

// your button click
onClick(){
callBack.mesage("Hi Activity");
}

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if ( context instanceof Callback ) {
        callback = (Callback) context;
    } else {
        throw new RuntimeException(context.getClass().getSimpleName()
                + " must implement Callback");
    }
}

public interface Callback(){
void message(String message);

}

Activity implements Callback{

@Overide
public void message(String message){
 System.out.println(message);

 // to refresh activity
 Intent intent = getIntent();
 intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
 finish();
 startActivity(intent);
 }
}

Answer 2

Define a method which do refresh operations in your activity.

public void refreshMyData(){
     // do your operations here.
}

And in your onClick method:

final Toolbar toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
toolbar.setNavigationIcon(R.drawable.ic_arrow_back_black_24dp);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            // If you use a generic toolbar you have to check instance of getActivity before cast.
           ((YourActivity)getActivity()).refreshMyData();
        }
    });

Edit : I refactored the code. I think you do not need post in onClick method.

Answer 3

Put this in your fragment

 public void refreshActivity(){
        ActivityName mDashboardActivity = (ActivityName) getActivity();
        if(ActivityName!=null){
            ActivityName.refreshMyData();
        }
    }

and put refreshMyData in your Activity

 public void refreshMyData(){
       //Code to refresh Activity Data hear 
    }

Let me know if not Working