onSaveInstanceState onRestoreInstanceState 在生命周期里的顺序

12-09 22:57:13.727 D/Lifecycle: onCreate
12-09 22:57:13.879 D/Lifecycle: onStart
12-09 22:57:13.889 D/Lifecycle: onResume
--------------- 旋转画面 -----------------------
12-09 22:57:19.375 D/Lifecycle: onPause
12-09 22:57:19.375 D/Lifecycle: onSaveInstanceState  (有些文章说 onSaveInstanceState在onPause之后)
12-09 22:57:19.379 D/Lifecycle: onStop
12-09 22:57:19.379 D/Lifecycle: onDestroy
12-09 22:57:19.434 D/Lifecycle: onCreate
12-09 22:57:19.434 D/Lifecycle: onActivityResult
12-09 22:57:19.434 D/Lifecycle: onReStart
​​​​​12-09 22:57:19.507 D/Lifecycle: onStart
12-09 22:57:19.508 D/Lifecycle: onRestoreInstanceState
12-09 22:57:19.510 D/Lifecycle: onResume

如果画面有dialog，fragment，在onRestoreInstanceState之前show的话，由于还没有状态，show里面执行commit时会发生以下提示错误。

Caused by: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
（编者：onSaveInstanceState之前实现commit的话，commit之后的状态就不被保存了。commit之后再onSaveInstanceState才能把frag状态保存下来）

//onResum之前show的逻辑，移到onResume里

    /** 把显示逻辑保存下来 */
    private var showFragmentsTask: (() -> Unit)? = null


    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
       //when (requestCode) {
       //    //show frag1处理
       //    //show frag2处理
       //}
       把上面的处理放到变量里
        showFragmentsTask = when (requestCode) {
           //show frag1处理
           //show frag2处理
           else -> null
        }
    }

    override fun onResumeFragments() {
        super.onResumeFragments()
        showFragmentsTask ?.invoke()
        showFragmentsTask = null
    }

 

参考

commitallowingstateloss 和commit的区别 https://www.dazhuanlan.com/2020/02/09/5e4006bd7e8ae/   

onActivityResult 调用时机 https://kokufu.blogspot.com/2012/09/onactivityresult.html

 

错误回避方法 https://kokufu.blogspot.com/2014/08/onactivityresult-dialogfragmentshow.html

本文地址：https://blog.csdn.net/vovo2000/article/details/107930230