java.lang.NullPointerException in Arrayadapter in android

Question

在arrayadapter上添加数据时出现空指针异常。得到误差

E/AndroidRuntime(9233): FATAL EXCEPTION: main

E/AndroidRuntime (9233): . lang。NullPointerException E/AndroidRuntime(9233): atco.adapter.TopicCustomDisplayArrayAdapter.getView (TopicCustomDisplayArrayAdapter.java: 415)

E/AndroidRuntime(9233): at co.util . twowayview . obtainview (TwoWayView.java:5599)E/AndroidRuntime (9233):co.utils.TwoWayView.onMeasure (TwoWayView.java: 3899)E/AndroidRuntime(9233): at android.view.View.measure(View.java:12773)

在我的代码中这样做:

 private View convertView;
 Holder holderText = null;
public TopicCustomDisplayArrayAdapter(Context context,
        ArrayList<fieldModel> arrayList) {
    super(context, R.layout.custom_display, arrayList);
    mInflater = (LayoutInflater) getContext().getSystemService(
        Context.LAYOUT_INFLATER_SERVICE);
    customTopicAd = arrayList;
    mcontext = context;
    options = new DisplayImageOptions.Builder().cacheInMemory(true)
        .cacheOnDisc(true).considerExifParams(true)
        .bitmapConfig(Bitmap.Config.RGB_565).build();
    }
    @Override
    public View getView(final int position, View cv, ViewGroup parent) {
    convertView = cv;
    AdTypeString = customTopic.get(position).getAd_Type();
    if (AdTypeString.equalsIgnoreCase("Text Ads")) {
        if (convertView == null) {
        convertView = mInflater.inflate(R.layout.text_view,
            parent, false);
        holderText = new Holder();
        holderText.textRelativeLayout = (RelativeLayout) convertView
            .findViewById(R.id.relativeTextAdView);
        convertView.setTag(holderText);
        } else {
        holderText = (Holder) convertView.getTag();
        }
        int widthTextAd = Integer.parseInt(customTopicAd.get(position)
            .getWidht());
        int heightTextAd = Integer.parseInt(customTopicAd.get(position)
            .getHeight();
        holderText.textRelativeLayout.getLayoutParams().width = widthTextAd;
        holderText.textRelativeLayout.getLayoutParams().height = heightTextAd;
        } else if (AdTypeString.equalsIgnoreCase("Image Ads")) {
       // display another layout
        }
   return convertView;
   }
  public static class Holder {
// Display Ads Resrouces
public RelativeLayout textRelativeLayout;

}

高度和宽度正常，但无法设置相对布局的高度和宽度。进入这一行:

holderText.textRelativeLayout.getLayoutParams()。width = widthTextAd;holderText.textRelativeLayout.getLayoutParams()。

知道如何纠正这个错误吗?这里数组列表的大小是5

Answer 1

似乎getLayoutParams()导致空指针，因为textRelativeLayout没有任何布局参数或任何大小。如果你想设置textRelativeLayout的大小，你可以考虑设置这个视图的layoutParams。所以改变

holderText.textRelativeLayout.getLayoutParams().width = widthTextAd;
holderText.textRelativeLayout.getLayoutParams().height = heightTextAd;

TwoWayView.LayoutParams lp = new TwoWayView.LayoutParams(widthTextAd, heightTextAd);
holderText.textRelativeLayout.setLayoutParams(lp);