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我们可以在这个特定场景中使用数据绑定替换findViewById()吗?

findviewbyid android-databinding android

Abhimanyu · 技术社区 · 6 年前

在谷歌安卓数据绑定之后,我一直在删除 findViewById() 在我的代码中。

我有一个回收器视图,在一个特定的项目视图中,每个按钮都有一个click listener。我正在设法消除方法。

// Add touch listener for the recycler view
    mainFragmentBinding.mainFragmentFoodItemsRecyclerView.addOnItemTouchListener(
            new RecyclerTouchListener(
                    getContext(),
                    mainFragmentBinding.mainFragmentFoodItemsRecyclerView,
                    new ClickListener() {

                        @Override
                        public void onClick(View view, final int position) {


                            Button addButton = view.findViewById(R.id.food_add_button);

                            addButton.setOnClickListener(addButtonView -> {

                                // Notify user
                                Toast.makeText(getContext(), "Clicked on Add button",
                                        Toast.LENGTH_SHORT).show();
                            });

                            // Values are passing to activity & to fragment as well
                            Toast.makeText(
                                    getContext(),
                                    "Single Click on position : " + position,
                                    Toast.LENGTH_SHORT
                            ).show();
                        }

                        @Override
                        public void onLongClick(View view, int position) {

                            Toast.makeText(
                                    getContext(),
                                    "Long press on position : " + position,
                                    Toast.LENGTH_LONG
                            ).show();
                        }
                    }
            ));

我想从上面的代码片段中更改的行:

Button addButton = view.findViewById(R.id.food_add_button);

这可能吗?如果是,有人能帮我做同样的事情吗?
或者我应该离开方法本身?

0 回复 | 直到 6 年前

Julio E. Rodríguez Cabañas 5 年前

为此,首先为数据绑定准备项目布局,并在其中添加单击回调:

?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>
        <variable
            name="item"
            type="com.example.your.item.Type"/>
        <variable
            name="parentViewModel"
            type="com.example.your.viewmodel.Type"/>
    </data>

    <YourLayout
        ...
        android:onClick="@{() -> parentViewModel.onItemClicked(item)}"
        ...
        YourLayout />

</layout>

lateinit var binding: YoutItemLayoutBindable

在适配器内部 onCreateViewHolder(...) ,确保使用数据绑定对项目布局进行充气:

val inflater = LayoutInflater.from(parent.context)
val binding = DataBindingUtil.inflate<YoutItemLayoutBindable>(inflater, R.layout.your_item_layout, parent, false)
val viewHolder = ViewHolder(binding.root)

// Pass your activity/fragment as the lifeCycleOwner when creating the adapter
binding.lifecycleOwner = lifeCycleOwner

// Pass also your viewmodel as a parameter when creating the adapter
binding.parentViewModel = parentViewModel

viewHolder.binding = binding

return viewHolder

onBindViewHolder(...)

val item = dataSet[position]
viewHolder.binding.item = item
viewHolder.binding.executePendingBindings()