java - 如果我没有在该特定类中声明它，如何在该类上调用 getItem 方法

Question

这个问题已经有答案了:

What is the main difference between Inheritance and Polymorphism? (18 个回答)

已关闭 5 年前。

public class WordAdapter extends ArrayAdapter<Word> {


public WordAdapter(Activity context, ArrayList<Word> words) {
    // Here, we initialize the ArrayAdapter's internal storage for the context and the list.
    // the second argument is used when the ArrayAdapter is populating a single TextView.
    // Because this is a custom adapter for two TextViews and an ImageView, the adapter is not
    // going to use this second argument, so it can be any value. Here, we used 0.
    super(context, 0, words);
}


@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    View listItemView = convertView;
    if(listItemView == null) {
        listItemView = LayoutInflater.from(getContext()).inflate(
                R.layout.list_item, parent, false);
    }
    Word currentWord = getItem(position);
    TextView miwokTextView = (TextView) listItemView.findViewById(R.id.miwok_text_view);

    miwokTextView.setText(currentWord.getmMiwokTranslation());

    TextView defaultTextView = (TextView) listItemView.findViewById(R.id.Default_text_view);

    defaultTextView.setText(currentWord.getmDefaultTranslation());

    ImageView iconView = (ImageView) listItemView.findViewById(R.id.image);
    // Get the image resource ID from the current AndroidFlavor object and
    // set the image to iconView
    iconView.setImageResource(currentWord.getmImageResourceId());

    return listItemView;
}
}

如果我没有在特定的类中声明它，我如何在该类上调用 getItem 方法。还请告诉我它是如何工作的以及它的用途。

上面给出的代码是一个基本的适配器类，它允许一个 Word 类包含两个字符串和一个图像资源整型变量及其 getter 方法。我的目的是在单个列表项中显示两个 TextView 和一个 ImageView 。代码很好，应用程序也运行良好。

Answer 1

getItem 定义在父类 ArrayAdapter. 中如果需要，您可以覆盖它。