Question

我有一个Custom适配器扩展BaseAdapter，它适用于导航抽屉。

但由于某种原因，一旦我设置了listview适配器，我就会收到错误; NullPointException;在getView()方法中，我声明了ImageView。尽管有许多研究我不明白为什么。有谁知道？该应用使用支持v7和ActionBarActivity

THX！

public class DrawerItemAdapter extends BaseAdapter {

 Context mContext;
 int mLayoutResourceId;
 ObjectDrawerItem mData[] = null;


// Constructor
public DrawerItemAdapter(Context context, int layoutResourceId, ObjectDrawerItem[] data) {
    this.mContext = context;
    this.mLayoutResourceId = layoutResourceId;
    this.mData = data;
}


@Override
public int getCount() {
    return mData.length;
}

@Override
public Object getItem(int position) {
    return mData[position];
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View listItem = convertView;
    ObjectDrawerItem objectDrawerItem = mData[position];

    LayoutInflater inflater = ((ActionBarActivity) mContext).getLayoutInflater();
    inflater.inflate(mLayoutResourceId, parent, false);

    ImageView iconImageView = (ImageView) listItem.findViewById(R.id.drawer_item_icon);
    TextView titleTextView = (TextView) listItem.findViewById(R.id.drawer_item_title);

    iconImageView.setImageDrawable(listItem.getResources().getDrawable(objectDrawerItem.getmIcon()));
    titleTextView.setText(objectDrawerItem.getmTitle());

    return listItem;
}
}

Answer 1

我正在看这条线： inflater.inflate(mLayoutResourceId, parent, false);

您似乎忘记将返回的视图分配给listItem

Answer 2

使用inflater.findViewById（）...

 ImageView iconImageView = (ImageView) inflater.findViewById(R.id.drawer_item_icon);
        TextView titleTextView = (TextView) inflater.findViewById(R.id.drawer_item_title);

用这个改变你的代码。

getView（）中的自定义适配器错误

2 个答案: