Adding buttons programmatically to a fragment

2019-06-15 12:49发布

I'm trying to programmatically add image buttons to the fragment that is a part of a viewpager. I tried different codes, but no button shows up even though Eclipse returns no error.

I found a similar question here but the answers didn't help me make my buttons appear.

Here is my code.

public class ViewPagerFragment extends Fragment {

private ViewPagerActivity mViewPagerActivity;
private String mId;

public ViewPagerFragment(String id) {
    mId = id;
}

@Override
public void onAttach(Activity activity) {
    if (activity instanceof ViewPagerActivity) {
        mViewPagerActivity = (ViewPagerActivity)activity;
    }
    super.onAttach(activity);
}

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

     int[] image_array = {
            R.drawable.elebutton,
            R.drawable.right,
            R.drawable.middle,
            };

     for (int i =0;i<image_array.length;i++){
            ImageButton b1 = new ImageButton(getActivity());
            b1.setId(100 + i);
             b1.setImageResource(image_array[i]);

            RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
            if (i > 0) {
                lp.addRule(RelativeLayout.BELOW, b1.getId() - 1);
            }   
            b1.setLayoutParams(lp);

            ImageHolder ih = new ImageHolder(getActivity());
            ih.addView(b1);


    }

    return v;

}
public class ImageHolder extends FrameLayout {

    public ImageHolder(Context context) {
        super(context);
        initView(context);
    }

    public ImageHolder(Context context, AttributeSet attrs) {
        super(context, attrs);
        initView(context);
    }

    public ImageHolder(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initView(context);
    }

    private void initView(Context context){
        View.inflate(context, R.layout.fragment, this); 
    }

   @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        // TODO Auto-generated method stub
        for(int i = 0 ; i < getChildCount() ; i++){
            getChildAt(i).layout(l, t, r, b);
        }
    }

}

2条回答
Melony?
2楼-- · 2019-06-15 13:28

It seems that you are creating i number of images, adding each of them to a imageholder. However, I did not see any part you actually join imageholders to main layout. So basically, these are created but not added to anywhere. Let us assume your R.layout.fragment has only a FrameLayout with id frameLayout1. Below would be my suggestion:

public class ViewPagerFragment extends Fragment {

private ViewPagerActivity mViewPagerActivity;
private String mId;

public ViewPagerFragment(String id) {
    mId = id;
}

@Override
public void onAttach(Activity activity) {
    if (activity instanceof ViewPagerActivity) {
        mViewPagerActivity = (ViewPagerActivity)activity;
    }
    super.onAttach(activity);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment, container, false);
}
// IMPORTANT PART! Here we will add images after fragment is inflated and instantiated
@Override
public void onActivityCreated(Bundle savedInstanceState) {
    // Get the root layout of fragment, we called it frameLayout1
    FrameLayout fl = (FrameLayout)(this.getActivity.findViewById(R.id.frameLayout1));
    int[] image_array = {
            R.drawable.elebutton,
            R.drawable.right,
            R.drawable.middle,
            };

     for (int i =0;i<image_array.length;i++){
            ImageButton b1 = new ImageButton(getActivity());
            b1.setId(100 + i);
             b1.setImageResource(image_array[i]);

            RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
            if (i > 0) {
                lp.addRule(RelativeLayout.BELOW, b1.getId() - 1);
            }   
            b1.setLayoutParams(lp);

            ImageHolder ih = new ImageHolder(getActivity());
            ih.addView(b1);
            fl.addView(ih);
    }
}
// End of important part
public class ImageHolder extends FrameLayout {...
}
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淡お忘
3楼-- · 2019-06-15 13:52

you can refer to my answer on Adding button to fragments dynamically.

Basically on your onCreateView method, implement this. Also, you should not use getActivity() for your ImageButton but use yourView.getContext() instead.

View myView = inflater.inflate(R.layout.fragment, container, false);

 for (int i = 0; i < image_array.length; i++) {

            final ImageButton b1 = new ImageButton(myView.getContext());
            b1.setImageResource(image_array[i]);
            b1.setId(i + 1);
            b1.setOnClickListener(this);

//Change the linearlayout to relative layout for your context
//you should set another layout within your R.layout.fragment
            LinearLayout linearlayout = (LinearLayout) myView.findViewById(R.id.btnholder); 
            linearlayout.setOrientation(LinearLayout.VERTICAL);

            LinearLayout.LayoutParams buttonParams = new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.MATCH_PARENT,
                    LinearLayout.LayoutParams.WRAP_CONTENT);
            buttonParams.setMargins(left, top, right, btm);

            linearlayout.addView(b1, buttonParams);
}

Hope this helps. I had the same problem for a while when I was creating normal button. If you need anything else, let me know :).

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