Jetpack Compose - remember, mutableStateOf, rememberSaveable

1, mutableStateOf: indicates that this data is stateful. If the state changes, all Views that reference this state need to be redrawn

2, remember: store the value, when the interface is redrawn, the previous value will be read, which is equivalent to adding another layer of content on top of mutableStateOf: store the value of this variable out of the function, that is, the value will not become the initial value if the function is executed again, but it will fail if the page is switched

3, rememberSaveable: On remember, it is guaranteed that data can be saved during page switching
rememberSaveable== remeber + onSaveInstanceState+ read savedInstanceState in onCreate
When configChanges,Write the value of remember into the bundle, and then read the data from the bundle when rebuilding the Activity