Windows Phone 8.1 RT-保存和加载页面状态

Question

I have 3 pages: first - MainPage, second - PivotPage, and third - SimplePage. I want to save the PivotPage state when I'm navigate to SimplePage and load it when go back. I tried to use NavigationHelper class but it also saves and load PivotPage state when I back from PivotPage to MainPage and then navigate to PivotPage again, which is not desirable. Does anyone can help me handle this?

EDIT:

I have 4 cases:

1. page with hub
2. page with pivot
3. page with pivot with lists
4. page with list

How to save and load position of selected item there?

Answer 1

Maybe this is what you need

add this to your constructor

    this.NavigationCacheMode = NavigationCacheMode.Required;

Answer 2

There are probably many ways to do what you want, but maybe simple flag would be sufficient (hence loading the state is fired in OnNavigatedTo ):

// provide a flag 
private bool ifLoadData = false;

// set the flag before state is loaded
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    ifLoadData = e.NavigationMode == NavigationMode.Back;
    // rest of the code

// then in LoadState just check if you want your data to be loaded
private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
{
    if (ifLoadData)
    {
       // load data