（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 <T : ViewBinding> AppCompatActivity.viewBinding(crossinline bindingInflater: (LayoutInflater) -> T) =lazy(LazyThreadSafetyMode.NONE) {bindingInflater.invoke(layoutInflater)}inline fun <T : ViewBinding> 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?) {}}