我试图在一个片段中创建一个ImageView,它将引用我在XML中为片段创建的ImageView元素。但是,findViewById方法仅在扩展Activity类时有效。我是否也可以在Fragment中使用它?

public class TestClass extends Fragment {
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        ImageView imageView = (ImageView)findViewById(R.id.my_image);
        return inflater.inflate(R.layout.testclassfragment, container, false);
    }
}

findViewById方法有一个错误,说明该方法未定义。


当前回答

非常简单的方法:

 @Nullable
        @Override
        public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
            View fragmentView = inflater.inflate(R.layout.testclassfragment, container, false);
            ImageView imageView = (ImageView)fragmentView.findViewById(R.id.my_image);
            return fragmentView;
       }

其他回答

1)首先膨胀Fragment的布局,然后使用findviewbyId。

View view = inflater.inflate(R.layout.testclassfragment, container, false);
             ImageView imageView = (ImageView) view.findViewById(R.id.my_image);
             return view;

你可以覆盖onViewCreated(),它在所有视图被膨胀后被调用。这是填充Fragment成员视图变量的正确位置。这里有一个例子:

class GalleryFragment extends Fragment {
    private Gallery gallery;

    (...)

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        gallery = (Gallery) view.findViewById(R.id.gallery);
        gallery.setAdapter(adapter);
        super.onViewCreated(view, savedInstanceState);
    }
}

首先获取片段视图,然后从这个视图获取ImageView。

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.testclassfragment, container, false);
    ImageView imageView = (ImageView) view.findViewById(R.id.my_image);
    return view;
}

试试这个,对我有用

public class TestClass extends Fragment {
    private ImageView imageView;

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.testclassfragment, container, false);
        findViews(view);
        return view;
    }

    private void findViews(View view) {
        imageView = (ImageView) view.findViewById(R.id.my_image);
    }
}

方法getView()不会在OnCreate和类似方法之外的片段上工作。

你有两种方法,将视图传递给oncreate上的函数(这意味着你只能在创建视图时运行你的函数)或将视图设置为变量:

private View rootView;

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

public void doSomething () {
    ImageView thumbnail = (ImageView) rootView.findViewById(R.id.someId);
}