（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(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::inflate),
    View.OnClickListener {

    override fun initView() {
        binding.play.setOnClickListener(this)
    }

    override fun onClick(p0: View?) {

    }

}

3. Fragment中使用

abstract class BaseFragment(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::inflate) {

    override fun initView(root: View, savedInstanceState: Bundle?) {
    }

}