OnBackPressed在Xamarin Android中

Question

我有:

public override void OnBackPressed ()
{
base.OnBackPressed ();
}

• 我怎样才能获得我的应用程序的先前状态？

• Xamarin是否具有BackStackEntryCount,我该如何使用它？

  例如,我单击MainMenu-> Study-> Categories-> FirstCategory,如果单击Back,我想要分类.

Answer 1

If the Categories activity precedes the Selected category in the activity stack and is not flagged for no history OnbackPressed without override of the base/super class will take you back to the categories class and hit the OnResume method.

If you loaded your Categories activity in OnCreate and dont do anything in OnResume then OnBackPressed should show the previous activity in the state you left it.

If you want it to do something else then override on OnBackPressed and flag Categories as no history.

Override OnBackPressed

public override void OnBackPressed()
{
    //Do not call the base method
    //base.Onbackpressed
    //Do something else
    *something else code*
    //finish this activity unless you want to keep it for some reason
    finish();

}

NoHistory

[Activity
     (

     NoHistory = true         

     )
 ]

 Public Class Categories : Activity