How to use onSavedInstanceState example please

Question

I m confused when it comes down to saving a state  So I know that onSaveInstanceState Bundle  is called when the activity is about to be destroyed  But how do you store your information in it and bring it back to its original state in onCreate Bundle savedInstanceState   I don t understand how this bundle will restore information  It would be helpful if someone can provide an example  The Dev guide doesn t do a good job of explaining this   public class Conversation extends Activity       private ProgressDialog progDialog      int typeBar      TextView text1      EditText edit      Button respond      private String name      private String textAtView      private String savedName       public void onCreate Bundle savedInstanceState           super onCreate savedInstanceState            setContentView R layout dorothydialog           text1    TextView findViewById R id dialog           edit    EditText findViewById R id repsond           respond    Button findViewById R id button01            if savedInstanceState    null               savedInstanceState get savedName               text1 setText savedName                     else              text1 setText  Hello  What is your name                 respond setOnClickListener new View OnClickListener                       Override                 public void onClick View v                        name   edit getText   toString                        text1 setText  Nice to meet you    name                                                              Override     public void onSaveInstanceState Bundle outState           super onSaveInstanceState outState           outState putString savedName  name

User · Answer

A good information  you don t need to check whether the Bundle object is null into the onCreate   method  Use the onRestoreInstanceState   method  which the system calls after the onStart   method  The system calls onRestoreInstanceState   only if there is a saved state to restore  so you do not need to check whether the Bundle is null

User · Answer

One major note that all new Android developers should know is that any information in Widgets  TextView  Buttons  etc   will be persisted automatically by Android as long as you assign an ID to them   So that means most of the UI state is taken care of without issue   Only when you need to store other data does this become an issue   From Android Docs      The only work required by you is to   provide a unique ID  with the   android id attribute  for each widget   you want to save its state  If a   widget does not have an ID  then it   cannot save its state

User · Answer

If Data Is not Loaded From savedInstanceState use following code   The problem is url call is not to complete fully so  check if data is loaded then to show the instanceState value      suppose data is not Loaded to savedInstanceState at 1st swipe if  savedInstanceState    null  amp  amp   mAlreadyLoaded       mAlreadyLoaded   true      GetStoryData     Url Call   else       if  listArray    null       Data Array From JsonArray ListArray          System out println  LocalData      listArray           view findViewById R id progressBar  setVisibility View GONE        else          GetStoryData     Url Call

User · Answer

Store information   static final String PLAYER SCORE    playerScore   static final String PLAYER LEVEL    playerLevel     Override public void onSaveInstanceState Bundle savedInstanceState           Save the user s current game state     savedInstanceState putInt PLAYER SCORE  mCurrentScore       savedInstanceState putInt PLAYER LEVEL  mCurrentLevel       Always call the superclass so it can save the view hierarchy state super onSaveInstanceState savedInstanceState       If you don t want to restore information in your onCreate-Method   Here are the examples  Recreating an Activity     Instead of restoring the state during onCreate   you may choose to implement onRestoreInstanceState    which the system calls after the onStart   method  The system calls onRestoreInstanceState   only if there is a saved state to restore  so you do not need to check whether the Bundle is null   public void onRestoreInstanceState Bundle savedInstanceState       Always call the superclass so it can restore the view hierarchy super onRestoreInstanceState savedInstanceState       Restore state members from saved instance mCurrentScore   savedInstanceState getInt PLAYER SCORE   mCurrentLevel   savedInstanceState getInt PLAYER LEVEL

User · Answer

This is for extra information   Imagine this scenario   ActivityA launch ActivityB  ActivityB launch a new ActivityAPrime by  Intent intent   new Intent getApplicationContext    ActivityA class   startActivity intent    ActivityAPrime has no relationship with ActivityA  In this case the Bundle in ActivityAPrime onCreate   will be null     If ActivityA and ActivityAPrime should be the same activity instead of different activities   ActivityB should call finish   than using startActivity

User · Answer

Basically onSaveInstanceState Bundle outBundle  will give you a bundle  When you look at the Bundle class  you will see that you can put lots of different stuff inside it  At the next call of onCreate    you just get that Bundle back as an argument  Then you can read your values again and restore your activity   Lets say you have an activity with an EditText  The user wrote some text inside it  After that the system calls your onSaveInstanceState    You read the text from the EditText and write it into the Bundle via Bundle putString  edit text value   theValue    Now onCreate is called  You check if the supplied bundle is not null  If thats the case  you can restore your value via Bundle getString  edit text value   and put it back into your EditText

User · Answer

The Bundle is a container for all the information you want to save  You use the put  functions to insert data into it  Here s a short list  there are more  of put functions you can use to store data in the Bundle   putString putBoolean putByte putChar putFloat putLong putShort putParcelable  used for objects but they must implement Parcelable    In your onCreate function  this Bundle is handed back to the program  The best way to check if the application is being reloaded  or started for the first time is   if  savedInstanceState    null           Then the application is being reloaded     To get the data back out  use the get  functions just like the put  functions  The data is stored as a name-value pair  This is like a hashmap  You provide a key and the value  then when you want the value back  you give the key and the function gets the value  Here s a short example    Override public void onSaveInstanceState Bundle outState       outState putString  message    This is my message to be reloaded       super onSaveInstanceState outState       Override public void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       if  savedInstanceState    null            String message   savedInstanceState getString  message            Toast makeText this  message  Toast LENGTH LONG  show              Your saved message will be toasted to the screen  Hope this helps

[android] How to use onSavedInstanceState example please

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