Android ImageButton worked well in Activity. It doesn't work in Fragment

问题

I'm trying to convert a layout so that it will include fragments. One of the views is an ImageButton that has a listener. The code worked fine as an Activity but makes trouble as a Fragment...

First problem was that I couldn't use findViewById, but I was able to find the answer for that here and fixed it with getView().

I can't find an answer to the second problem... after I declared:

ImageButton camBt = (ImageButton)getView().findViewById(R.id.button1);

I want to set an on click listener:

camBt.setOnClickListener(listener);

But it keeps acting like the ImageButton (camBt) doesn't exist... I don't even know what's the problem... it worked fine in the Activity...

Here's the full code. Many thanks!

public class CameraFragment extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {
    View V = inflater.inflate(R.layout.camera_fragment, container, false);
    return V;
}

ImageButton camBt = (ImageButton)getView().findViewById(R.id.button1);
camBt.setOnClickListener(listener);

ImageButton.OnClickListener listener = new ImageButton.OnClickListener()
{

@Override
public void onClick(View arg0)
{
Camera.open().getParameters();
}
}; 
}

回答1:

Move

ImageButton camBt = (ImageButton)getView().findViewById(R.id.button1);
camBt.setOnClickListener(listener);

inside onCreateView().

Like

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

    // Here it is
    ImageButton camBt = (ImageButton)v.findViewById(R.id.button1);
    camBt.setOnClickListener(listener);


    return v;
}

---

And one more thing you need to understand that variable name should starts with small letter. So you should use View v instead of View V.

回答2:

You should add

ImageButton camBt = (ImageButton)getView().findViewById(R.id.button1);
camBt.setOnClickListener(listener);

inside onCreateView() like:

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

ImageButton camBt = (ImageButton)v.findViewById(R.id.button1);

camBt.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub

        }
    });

return V;
}

回答3:

     public class CameraFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
               View V = inflater.inflate(R.layout.camera_fragment, container, false);
        ImageButton camBt = (ImageButton)V.findViewById(R.id.button1);


         ImageButton.OnClickListener listener = new ImageButton.OnClickListener()
            {

            @Override
              public void onClick(View arg0)
                  {
                  Camera.open().getParameters();
                  }
              }; 
        camBt.setOnClickListener(listener);
            return V;
    }


  }

来源：https://stackoverflow.com/questions/21903654/android-imagebutton-worked-well-in-activity-it-doesnt-work-in-fragment