我试图遵循官方谷歌文档https://developer.android.com/tools/data-binding/guide.html的数据绑定示例

除了我试图将数据投标应用到一个片段,而不是一个活动。

编译时我目前得到的错误是

错误:(37,27)没有指定资源类型(at 'text' with value '@{marsdata.martianSols})。

onCreate for fragment是这样的:

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    MartianDataBinding binding = MartianDataBinding.inflate(getActivity().getLayoutInflater());
    binding.setMarsdata(this);
}

onCreateView for fragment看起来像这样:

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    return inflater.inflate(R.layout.martian_data, container, false);
}

和部分我的布局文件片段看起来像这样:

<?xml version="1.0" encoding="utf-8"?>

<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="marsdata"
            type="uk.co.darkruby.app.myapp.MarsDataProvider" />
    </data>
...

        <TextView
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:text="@{marsdata.martianSols}"
        />

    </RelativeLayout>
</layout>

我的怀疑是MartianDataBinding不知道它应该与哪个布局文件绑定-因此出现错误。有什么建议吗?


当前回答

Kotlin 语法:

lateinit var binding: MartianDataBinding
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    binding = DataBindingUtil.inflate(inflater, R.layout.martian_data, container, false)
    return binding.root
}

其他回答

在我的代码中工作。

private FragmentSampleBinding dataBiding;
private SampleListAdapter mAdapter;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    super.onCreateView(inflater, container, savedInstanceState);
    dataBiding = DataBindingUtil.inflate(inflater, R.layout.fragment_sample, null, false);
    return mView = dataBiding.getRoot();
}

可以像下面提到的那样简单地检索视图对象

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

View view = DataBindingUtil.inflate(inflater, R.layout.layout_file, container, false).getRoot();

return view;

}

在Android DataBinding中试试这个

FragmentMainBinding binding;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        binding = DataBindingUtil.inflate(inflater, R.layout.fragment_main, container, false);
        View rootView = binding.getRoot();
        initInstances(savedInstanceState);
        return rootView;
}

Kotlin中的最短路径;

class HomeFragment : Fragment(R.layout.fragment_home) {


override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    val binding = FragmentHomeBinding.bind(view)
    // todo 
    }

非常有用的关于数据绑定的博客: https://link.medium.com/HQY2VizKO1

class FragmentBinding<out T : ViewDataBinding>(
    @LayoutRes private val resId: Int
) : ReadOnlyProperty<Fragment, T> {

    private var binding: T? = null

    override operator fun getValue(
        thisRef: Fragment,
        property: KProperty<*>
    ): T = binding ?: createBinding(thisRef).also { binding = it }

    private fun createBinding(
        activity: Fragment
    ): T = DataBindingUtil.inflate(LayoutInflater.from(activity.context),resId,null,true)
}

在Fragment中像这样声明binding val:

private val binding by FragmentBinding<FragmentLoginBinding>(R.layout.fragment_login)

别忘了把这段话分段写下来

override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    return binding.root
}