在一个片段中以编程方式添加按钮

Question

我正在尝试通过编程方式向作为ViewPager一部分的片段中添加图像按钮。我尝试了不同的代码，但即使Eclipse没有返回错误，也没有显示任何按钮。

我在这里找到了一个类似的问题（链接），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);
        }
    }

}

- Jason O.

---

看起来你正在将按钮添加到ih对象中，同时为每个按钮创建了一个ImageHolder，但是没有向真正的布局视图v中添加任何内容。所以也许你应该将b1添加到v中 => v.addView(b1)。如果这样做有帮助，请告诉我。 - alexscmar

Answer 1

你可以参考我的回答动态添加Fragment中的按钮。

基本上，在你的onCreateView方法中实现这个。另外，你不应该使用getActivity()来获取ImageButton，而是应该使用yourView.getContext()。

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);
}

希望这可以帮到你。我在创建普通按钮时也遇到了同样的问题一段时间。如果你需要其他帮助，请告诉我 :)。

- Jayden Choi

Answer 2

看起来你正在创建i张图片，将它们添加到一个图像容器中。然而，我没有看到任何部分实际上将图像容器连接到主布局中。所以基本上，这些被创建了但是没有添加到任何地方。假设你的R.layout.fragment只有一个id为frameLayout1的FrameLayout。下面是我的建议：

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 {...
}

- Can Gokdere