（笔记）Kotlin——Android封装ViewBinding之二 优化

 0. 在app模块的build.gradle文件中添加如下配置开启ViewBinding 

 
android {
    .......
 
    viewBinding {
        enabled = true
    }
 
}

1. 新建一个Ext.kt文件 

添加两个扩展函数，分别对应Activity和Fragment

inline fun  AppCompatActivity.viewBinding(crossinline bindingInflater: (LayoutInflater) -> T) =
        lazy(LazyThreadSafetyMode.NONE) {
            bindingInflater.invoke(layoutInflater)
        }
 
 
inline fun  Fragment.viewBinding(crossinline bindingInflater: (LayoutInflater, ViewGroup? , Boolean) -> T) =
        lazy(LazyThreadSafetyMode.NONE) {
            bindingInflater.invoke(layoutInflater, view?.parent as? ViewGroup, false)
        }

2. Activity中使用

BaseActivity

public abstract class BaseActivity<VB : ViewBinding>(inflater: (LayoutInflater) -> VB) :
    AppCompatActivity() {
 
    protected val binding by viewBinding(inflater)
 
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)
        initView()
        initData()
    }
 
    protected fun initView() {}
 
    protected fun initData() {}
 
}

继承自BaseActivity的子类 

class VideoPlayerActivity : BaseActivity<ActivityVideoPlayerBinding>(ActivityVideoPlayerBinding::inflate),
    View.OnClickListener {
 
    override fun initView() {
        binding.play.setOnClickListener(this)
    }
 
    override fun onClick(p0: View?) {
 
    }
 
}

3. Fragment中使用

abstract class BaseFragment<VB : ViewBinding>(inflater: (LayoutInflater, ViewGroup?, Boolean) -> VB)
    : Fragment() {
 
    protected val binding by viewBinding(inflater)
 
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        initView(binding.root, savedInstanceState)
        return binding.root
    }
 
    abstract fun initView(root: View, savedInstanceState: Bundle?)
 
}

继承自BaseFragment的子类

class TestFragment : BaseFragment<FragmentTestBinding>(FragmentTestBinding::inflate) {
 
    override fun initView(root: View, savedInstanceState: Bundle?) {
    }
 
}