Jetpack Navigation和viewModel实现fragment的切换和数据共享

Navigation的使用请看笔者的另一笔记

https://blog.csdn.net/rolandlee01/article/details/105473193

本案例来自于：

https://b23.tv/BV1w4411t7UQ/p19

一、介绍

个人理解：ViewModel的生命周期与Activity生命周期一致，故可以通过在fragment中获取viewModel来实现fragment之间的数据共享，如有错误欢迎指正

二、关键代码—fragment 中获取viewModel

//fragment 中获取viewModel 
override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        //viewmodel的持有者为Acitvity
        mViewModel=ViewModelProvider(activity!!).get(MyViewModel::class.java)
        var binding:FragmentDetailBinding=DataBindingUtil.inflate(inflater,R.layout.fragment_detail,container,false)
        binding.data=mViewModel
        //databing的生命周期也是与Activity一致
        binding.lifecycleOwner=activity
        return binding.root
    }

案例地址