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

你必须放大视图

public class TestClass extends Fragment {

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

其他回答

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);
    }
}

try

private View myFragmentView;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
{
myFragmentView = inflater.inflate(R.layout.myLayoutId, container, false);
myView = myFragmentView.findViewById(R.id.myIdTag)
return myFragmentView;
}

使用gradle skeleton插件,它会自动生成视图持有者类,并引用到你的布局。

public class TestClass extends Fragment {
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        MyLayout myLayout = new MyLayout(inflater, container, false);
        myLayout.myImage.setImageResource(R.drawable.myImage);
        return myLayout.view;
    }
}

现在假设你在my_layout.xml文件中声明了一个ImageView,它会自动为你生成myLayout类。

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;
       }

在onCreateView方法中

1)首先你必须膨胀你想要添加的布局/视图 如。LinearLayout

LinearLayout ll = inflater.inflate(R.layout.testclassfragment, container, false);

2)然后你可以从布局中找到你的imageView id

ImageView imageView = (ImageView)ll.findViewById(R.id.my_image);

3)返回膨胀的布局

return ll;