java - “this”关键字不返回上下文

我定义了自己的自定义ArrayAdapter，名为WordAdapter，如下所示：

public class WordAdapter extends ArrayAdapter<Word> {
Context context;

public WordAdapter(Context context, ArrayList<Word> words) {
    super(context, 0, words);
    this.context = context;
}

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

    // Check if the existing view is being reused, otherwise inflate the view
    View listItemView = convertView;
    if (listItemView == null) {
        listItemView = LayoutInflater.from(getContext()).inflate(R.layout.list_item, parent, false);
    }

    Word currentWord = getItem(position);

    TextView miwok = (TextView) listItemView.findViewById(R.id.miwok_text_view);
    miwok.setText(currentWord.getMiwokTranslation());

    TextView english = (TextView) listItemView.findViewById(R.id.english_text_view);
    english.setText(currentWord.getEnglishTranslation());

        return listItemView;
    }
}

我在一个类中需要它，它的用法如下：

public class NumbersActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.word_list);

    ArrayList<Word> words = new ArrayList<>();
    words.add(new Word("lutti","one"));
    words.add(new Word("otiiko","two"));
    words.add(new Word("toldokosu","three"));
    words.add(new Word("oyyisa","four"));
    words.add(new Word("massoka","five"));
    words.add(new Word("temmoka","six"));
    words.add(new Word("kenekaku","seven"));
    words.add(new Word("kawinta","eight"));
    words.add(new Word("wo'e","nine"));
    words.add(new Word("na'aacha","ten"));

    WordAdapter itemsAdapter = new WordAdapter(this, words);

    ListView listView = (ListView) findViewById(R.id.list);

    listView.setAdapter(itemsAdapter);


    }
}

但是它在WordAdapter itemsAdapter = new WordAdapter(this, words);行中给出了错误，说


  WordAdapter（android.content.Context ArrayList）无法应用于com.example.android.miwok.NumbersActivity ArrayList


依存关系：

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.3.0'
    compile 'com.android.support:design:23.3.0'
    compile 'com.android.support:support-v4:23.3.0'
}

最佳答案

我可以说您的代码没有问题。 AppCompatActivity是Context本身。因此，传递"this"应该仍然有效。

如我所见，存在依赖冲突。如果添加了appcompat依赖项，则也不必添加support V4依赖项，因为supportv4软件包已经附带了appcompat依赖项。

我的建议是删除support v4依赖项并再次与gradle同步。那应该没问题
即使它不起作用，也只需再执行一个步骤即可。
点击File -> Invalidate/Cache Restart -> Click on Invalidate cahe and Restart.

现在我很确定，这个问题不会出现。