以编程方式将按钮添加到片段

Question

我正在尝试以编程方式将图像按钮添加到作为viewpager一部分的片段中.我尝试了不同的代码,但即使Eclipse没有返回任何错误也没有按钮显示.

我在这里发现了一个类似的问题,但答案并没有帮助我让我的按钮出现.

这是我的代码.

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);
        }
    }

}

Answer 1

看来您正在创建 i 个图像，并将每个图像添加到图像持有者中。但是，我没有看到您实际将图像持有者加入到主布局的任何部分。所以基本上，这些是被创建的，但没有添加到任何地方。让我们假设您的 R.layout.fragment 只有一个 ID 为frameLayout1 的FrameLayout。以下是我的建议：

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 {...
}