无法定制SimpleAdapter

Question

这是我的适配器

public class Vk_row_adapter extends SimpleAdapter {
final String ATTRIBUTE_NAME_TEXT_NAME = "text_name";
final String ATTRIBUTE_NAME_TEXT_PLACE = "text_place";
final String ATTRIBUTE_NAME_IMAGE = "image";
private List<? extends Map<String, ?>> results;


public Vk_row_adapter(Context context, List<? extends Map<String, ?>> data, int resource, String[] from, int[] to) {
    super(context, data, resource, from, to);
    this.results = data;
}
public View getView(int position, View view, ViewGroup parent){

    View v = view;

    TextView tt = (TextView) v.findViewById(R.id.vk_name);
    tt.setText((CharSequence) results.get(position).get(ATTRIBUTE_NAME_TEXT_NAME));

    TextView bt = (TextView) v.findViewById(R.id.vk_raiting);
    tt.setText((CharSequence) results.get(position).get(ATTRIBUTE_NAME_TEXT_PLACE));

    ImageView vt = (ImageView)v.findViewById(R.id.vk_photo);
    vt.setImageBitmap((android.graphics.Bitmap) results.get(position).get(ATTRIBUTE_NAME_IMAGE));

    return v;
}

}它给了我一个错误：java.lang.NullPointerException at TextView tt = (TextView) v.findViewById(R.id.vk_name);，哪里是我的错误？我认为错误在创建视图中

Answer 1

在使用XML之前，首先需要膨胀XML(XML包含行的布局)。

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

    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    View rowView = inflater.inflate(R.layout.rowlayout, parent, false);

    TextView textView = (TextView) rowView.findViewById(R.id.label);

    ...

我认为您可以使用ViewHolder模式(安卓文档推荐它)。

请参见：

• 在视图保持器中保存视图对象
• Android ViewHolder模式示例