如何从Activity为Fragment的开关设置OnClickListener？

Question

I have an Activity which has a Fragment. This Fragment has different switches and buttons. Now I can access these Fragment's elements from the Activity.

Now, I want to set an OnClickListener on the Fragment's switch but in the Activity itself. Problem is, from the Activity second time onward switch is not listening.

Answer 1

For switch I recommend OnCheckedChangeListener instead of OnClickListener for listenning events

 mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (isChecked) {
                 // do something when check is selected
            } else {
                 //do something when unchecked
            }
        }
    });

Hope this help

Answer 2

You can have your onClickListener in a method in you Activity class like below:

public OnClickListener switchClickListener()
{
    return new OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            //code here
        }
    };
}

And you can call this method from your fragment and set the Switch OnClicklistener with the code below:

switch.setOnClickListener( ((Activity) getActivity).switchClickListener());

Answer 3

You can implement OnClickListener at your actvity and on attach you can use that to call onclicklistener. At activity-

public class MainActivity extends AppCompatActivity implements OnClickListener {
....
@Override
public void onClick(View view) {
    switch (view.getId()){

    }
}
}

And at fragment-

MainActivity mainActivity;
Button button;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_test, container, false);
    button = (Button) view.findViewById(R.id.button);
    return view;
}


@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    mainActivity = (MainActivity) activity;
    button.setOnClickListener(mainActivity);
}

Note - The above code works only when your fragment is attached with activity. Recommended way is to use callbacks.