1.首先build.gradle内配置 viewBinding=true 不行试试 viewBinding true
android {
buildFeatures {
viewBinding=true
}
buildFeatures {
viewBinding true
}
}
2.如果有些布局文件你不希望为它生成对应的Binding类，可以在该布局文件的根元素位置加入如下声明：
<LinearLayout
xmlns:tools="http://schemas.android.com/tools"
...
tools:viewBindingIgnore="true">
...
</LinearLayout>
- 查看代码中备注 注意 1.2.3 ActivityMainBinding不是固定是你生成哪个文件就是哪个名字
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding //注意1
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater) //注意2
setContentView(binding.root) //注意3
binding.textView.text = "Hello"
}
}
4.在Fragment中使用ViewBinding
假设我们有一个布局文件叫fragment_main.xml，那么启用ViewBinding功能之后，则必然会生成一个与其对应的FragmentMainBinding类。
class MainFragment : Fragment() {
private var _binding: FragmentMainBinding? = null
private val binding get() = _binding!!
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
_binding = FragmentMainBinding.inflate(inflater, container, false)
return binding.root
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
5.在Adapter中使用ViewBinding
假设我们定义了fruit_item.xml来作为RecyclerView子项的布局：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp">
<ImageView
android:id="@+id/fruitImage"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_gravity="center_horizontal"
android:layout_marginTop="10dp" />
<TextView
android:id="@+id/fruitName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:layout_marginTop="10dp" />
</LinearLayout>
然后编写如下RecyclerView Adapter来加载和显示这个子项布局：
class FruitAdapter(val fruitList: List<Fruit>) : RecyclerView.Adapter<FruitAdapter.ViewHolder>() {
inner class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
val fruitImage: ImageView = view.findViewById(R.id.fruitImage)
val fruitName: TextView = view.findViewById(R.id.fruitName)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val view = LayoutInflater.from(parent.context).inflate(R.layout.fruit_item, parent, false)
return ViewHolder(view)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val fruit = fruitList[position]
holder.fruitImage.setImageResource(fruit.imageId)
holder.fruitName.text = fruit.name
}
override fun getItemCount() = fruitList.size
}
6.对引入布局使用ViewBinding include merge
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include
android:id="@+id/titleBar"
layout="@layout/titlebar" />
...
</LinearLayout>
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
binding.titleBar.title.text = "Title"
binding.titleBar.back.setOnClickListener {
}
binding.titleBar.done.setOnClickListener {
}
}
}
merge
<merge xmlns:android="http://schemas.android.com/apk/res/android">
<Button
android:id="@+id/back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:text="Back" />
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="Title"
android:textSize="20sp" />
<Button
android:id="@+id/done"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:text="Done" />
</merge>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include
layout="@layout/titlebar" />
</LinearLayout>
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
private lateinit var titlebarBinding: TitlebarBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater)
titlebarBinding = TitlebarBinding.bind(binding.root)
setContentView(binding.root)
titlebarBinding.title.text = "Title"
titlebarBinding.back.setOnClickListener {
}
titlebarBinding.done.setOnClickListener {
}
}
}
