Android Application Development Tutorial - 95 - Saving Data with SharedPreferences

what's up guys welcome to your 95th
Android tutorial for the new boss in
again with me Travis and what we're
going to do this tutorial or in the next
few tutorials we're going to work with
some data saving data the phone saving
data privately so no one else can access
that data publicly on the SD card and
just some basically some primitives that
we can save as well so I'm going to show
you different ways that you can save and
how to do that we're going to get into a
little bit more depth than what we have
worked with previously as you can see
I've set up an XML layout called shared
preferences and also a a class called
shared prefs so this is just the XML
file here where we have edit text a Save
button a load button and then a just a
text view down here and what I've done
is I've created this class game called
shared prefs and we have two variables
we want to use throughout all of our
class so we define them above again our
edit text center textview called mine
shared prat or shared data and data
results then within the on create method
I just said I'll you know set up to our
XML file and also I created this method
called set up variables which is right
here which is again adds those
references from our XML file and then I
set our save and our load button to be
have an onclicklistener which is this so
we again implemented onclicklistener
and this switching case set that up so
hopefully you guys you shouldn't be
confused with that because we've done
this numerous of times so again I just
trying to save some time for you and not
type that out hopefully as if you have
informed the series you should probably
be able to do that easily by now in your
sleep so let's get into it as you can
see this type of data is called shared
preferences that's the way we're going
to save our data and reach and receive
our data and we've used shared
preferences before when we had a
Preferences class where we you know
turn off the music for Splash activity
I'm just stuff like that but we're going
to go into a little bit more depth and
just to clarify the shared preference is
is a way to store private primitive data
and like a key value pair and that was
the definition off the Android developer
page so it's basically we're using key
and value pairs to save data and we can
just save like strings stuff simply like
that boolean's different types of
variables for the most part so what
we're going to do within our on create
or our on click method for our save is
we're going to get our edit text and
read the text and convert it into a
string as always so we're going to say
string then we're just going to call
this like string data something like
that and again we just use our edit text
which we called shared data dot get text
and then to string so again nothing new
there and what we've done is we've set
up a string variable and this is the
kind of variable that we want to save
and when we're working with with this
shared the shared preferences type of
saving we need to have some kind of file
name so what we're going to do is we're
going to create that file name above our
classes right here with our edit text in
our text view and it's going to be a
string so we're going to say string and
we're just going to say prefs or are
going to say our file name something
like that and we're just going to set
this equal to my my data or my string
data my shared string something like
that my shared string and we don't want
this file name to change so what we're
going to say is we're going to say
static and basically what static means
is it's like hey don't try and change it
jerk just keep it same and everything's
going to be cool so basically this
filename will never change basically is
that what's that saying or it can't
change and what we're going to say is
we're also going to say public so other
you know activities can access this file
name if we need to so there we go and
now what we're going to do is we're just
going to use the shared preferences to
save this string that we created down
here within our on click of our Save
button so we convert it into a string
and then all we have to do is we got to
create a shared preferences basically
object where we're going to save this
stuff so we're going to do that within
our on create method as well and again
we're going to say shared preferences
and we're going to say shared string
ernõ yeah we're just going to say some
data something like that and again we
have to import this and what we're going
to do is we're going to say get shared
preferences
and then what what kind of we're going
to access our file name so we're going
to just say file name and then comma and
zero so let's check it check out what
this gets shared preferences is and it
basically says retrieves and hold the
content of a preference file name
returning let's just get down to the
second parameter so let's just get down
to the mode so basically what the mode
says is it's kind of the way that we
want to be able to write this so use
zero or mode private for the default
operation which we're going to do but
you can also do mode world readable so
the world can read and write able to
control permissions and you know some
other options that you can use for that
second parameter but now what we've done
is we've set up the shared preferences
and what we're going to do actually is
also define this above so we're just
going to copy and paste this above our
class or above our on create method and
then we're going to define it down here
some data and now all we have to do is
we can basically use an editor to edit
what this you know what this filename
has within it because right now it's
just loading this filename which the
first time we run this application it's
going to have nothing so we're loading
the file name and now we want to be able
to edit it within our say