Check if app open the first time

Sometime we want to show a notification just one time when user first open app.

We will use SharedPreferences to do this.

Copy this lines to below setContentView.

final String MYPREFS = "mySave";

int mode = Activity.MODE_PRIVATE;

SharedPreferences mySharedPreferences = getSharedPreferences(MYPREFS,mode);

SharedPreferences.Editor editor = mySharedPreferences.edit();

int number = mySharedPreferences.getInt("number", 1);

editor.putInt("number", 200);

editor.commit();

We use a variable name number to get saved value, we put the line int number = mySharedPreferences.getInt("number", 1); above the line editor.putInt("number", 200); so that in the first time app open, the value of number=1, next time number=200.

And we use if command to show text or do any thing you want.

if(number==1){

Toast.makeText(MainActivity.this, "This is the first open",

                               Toast.LENGTH_SHORT).show();

}