android - findViewById 不是由 Fragment 定义的

Question

AutoCompleteTextView autoCompView = 
          (AutoCompleteTextView) findViewById(R.id.autocomplete_city);

给我一个错误

对于 CityFragment 类型，方法 findViewById 未定义。

和：

public class CityFragment extends Fragment {

    public CityFragment() {}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.city,
                    container, false);

    AutoCompleteTextView autoCompView = 
                (AutoCompleteTextView) findViewById(R.id.autocomplete_city);

        autoCompView.setAdapter(
                       new PlacesAutoCompleteAdapter(this, R.layout.list_item)
                );

    return rootView;
    }
}

我基本上只是从https://developers.google.com/places/training/autocomplete-android复制了代码

任何想法为什么我会收到错误？

Answer 1

那是因为确实Fragment没有这样的方法findViewById()。相反，您应该使用rootView来访问它。

AutoCompleteTextView autoCompView = 
                (AutoCompleteTextView)rootView.findViewById(R.id.autocomplete_city);

Answer 2

更改为：

AutoCompleteTextView autoCompView = 
                (AutoCompleteTextView) rootView.findViewById(R.id.autocomplete_city);

Answer 3

改变：

AutoCompleteTextView autoCompView = 
          (AutoCompleteTextView) findViewById(R.id.autocomplete_city);

至：

AutoCompleteTextView autoCompView = 
                (AutoCompleteTextView) rootView.findViewById(R.id.autocomplete_city);

Answer 4

这里 rootView 是 AutoCompleteTextView 的父级。所以改变它：

AutoCompleteTextView autoCompView = 
                (AutoCompleteTextView) rootView.findViewById(R.id.autocomplete_city);