I am working on my application and I want to change the color of their UI with the click of button.....Like this....
Button change=findViewById(R.id.change_UI);
change.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//My code to change the color of UI
//like blue to green-red-black etc (randomly)
}
The above things are working fine but when I again restart my application all things were same as I open it first time...with blue color UI.
I am new for development and i know this question is not so much interested but please help to solve this problem.
You should use SharedPreferences for this case. There is no problem for using it when you have more than 1 variable so don't worry.
Here is link to another answer how to use it properly: Android Shared preferences example
Another option could be creating one object which will hold all settings data and save it to a file and read it with every app run but for your case it would be overkill.
EDIT:
SharedPreferences data are stored in an XML file, a good practice would be not to store there more than 100kb. If you want to store something bigger you SQL database like Room or save yout data to file.
More information you can find here: Shared Preferences "limit" or in this answer https://stackoverflow.com/a/30638736/6329985
You can setup a preference activity as in here.
Related
I want to save the highscore created in the game and can be seen in the main menu when the player hits the highscore button, can someone help me?
you can use SQLITE to save the highscore to database another way is make a file that write the score to a Text File and save it to the directory of the system
You can solve your problem in a easier way..
Just declare a Variable for the Score like this..
local score=0
Then Increment the score variable by 1 whenever it hits the paddle. So Insert the coding in Collision Function as given below:
local function onCollision(event)
{
score=score+1
}
ball.collision=onCollision
ball:addEventListener("collision",ball)
Finally When you need to save your highscore (after gameover), You can use Preference instead of json which makes the larger coding.
local preference= require "preference"
local highscore=0
preference.save{highscore=score}
If you want to display the Highscore, then use the following:
highscore_value=preference.getValue("highscore")
display.newText(highscore_value,0,0,nil,30)
This might be useful for your problem !!
Multiple libraries exist for this purpose.
GGScore is an open source library built by GlitchGames which can easily allow you to do this: GlitchGames/GGScore
All the documentation you need is in the main page (README.md) so there isn't really a need for me to explain the code. But it's really easy to use.
When I originally wrote and published my app, I was using a custom written activity to handle application settings. I used custom file name to store shared preferfences, like this:
getSharedPreferences("custom_settings_file",MODE_PRIVATE);
But now I'm refactoring my app and I would like to implement PreferenceActivity or PreferenceFragment and an xml file with PreferenceScreen section. Every tutorial or example that I've seen is using
getDefaultSharedPreferences(context);
to retrieve shared preferences, because PreferenceActivity assumes default filename to store preferences and there's no way to tell it to use a different one(at least I couldn't find one after an hour of searching and reading documentation).
So now I have a problem. If I just simply use the new default file, existing users of my app will lose their settings when they update the app, because the new application will not know anything about "custom_settings_file". What would be the best way to move the data from an old file to a new one on app update?
Here are the possible options that I could come up with:
Extend Application class and implement a piece of code in onCreate() so that every time my app is launched, it would check for existence of "custom_settings_file" and move it's contents to the new one. But running a block of code on every app launch seems like wasting too much processing resources for an operation that only needs to run once.
Just notify the user that their old settings are gone. But obviously this is not acceptable.
Is there a better solution, than option 1? Perhaps someone has already faced a similar problem?
What is preventing you from doing number 1 only once?
Just add a "migration" boolean to the new sharedpreferences.
If you also load the xml preference file then you can try this:
PreferenceManager.setDefaultValues(context, YOUR_PREFERENCE_NAME, MODE_PRIVATE, R.xml.preference_file, false);
If not (you want to add each preference item dynamically in your code) then you can do like this:
PreferenceManager pm = getPreferenceManager();
pm.setSharedPreferencesMode(MODE_PRIVATE);
pm.setSharedPreferencesName(YOUR_PREFERENCE_NAME);
In case you still want to use the defaultSharedPreference and process the migration then ... I'm writing this and I see Nicklas's answer, so I'm done here.
Could you add value in your new SharedPreferences that records whether you are a new install or an upgrade. If you don't have the setting in your sharedpreferences, check to see if you have an old preferences file in the way you were before. Then convert those preferences to your new method, and set your private setting indicating that it's been upgraded. Then just set the new value indicating the new state and you won't need to check your old preferences any more.
I am working a project. I have lots of word text data and don't want to add layout and class for each one. I want to use sqlite, but don't know how. For example, there is a button, id is cat.
When clicking the cat button, a new screen opens and shows information of cat. One layout, one class, but lots of screens. The data must come from sql because there are too many animals.
Thanks in advance.
You have given the answer already yourself: SQL database may be your friend. Work yourself through this tutorial and see how far that brings you. You'll have to manipulate the UI from code, that is doable as well.
Another approach you might want to consider is putting everything in XML into strings.xml file(s). This depends a bit on the size and structure of your data. From code you can reach this using getString( R.id.blah ).
Call other screen passing values.
In the button click do:
startActivity(new Intent(this, SecondScreen.class).putExtra('Identify', 'Value'));
In the Second Screen do:
String value = getIntent().getStringExtra('Identify');
Now, take that value and make the query in SqLite and display the result.
I just implemented a preferences screen for one of the sample apps that I am creating. I followed the guide given on google site. All is fine and I loaded up a ListPreference and I am able to store it and persist it also. There is also one minor problem here. I have already defined a custom preference file for the app but this automatic handling of the preference screeen seems to be creating a preference file on its own. For now I was trying to get this code to work but it is not getting the custom preference file.
final Preference customPrefs = getPreferenceScreen().findPreference(Utils.PREFS_NAME);
customPrefs.setOnPreferenceClickListener(new OnPreferenceClickListener() {
public boolean onPreferenceClick(Preference preference) {
customPrefs.getEditor().commit();
return true;
}
});
Is there a way to bind the custom preference file with this auto preference class in anyway ?
You can set a custom name for the file used to store the preferences, used in your PreferenceActivity, by calling its getPreferenceManager().setSharedPreferencesName("file_name") method. Just remember that you need to set that before calling addPreferencesFromResource, otherwise your UI will still change stuff back to the wrong file (the default one).
As I said, you don't need to do that, since you can use the default file provided by the system. If/when you need to read the preferences elsewhere, you can then just call PreferenceManager.getDefaultSharedPreferences(Context context).
I already addressed those remarks in another question.
Also remember that some of the methods are deprecated. If you're writing new code, try to avoid them and conform to the new "Fragment Way" of doing things.
Hi I need a little help with an issue that I have.
I had to build an application which needs to show only a text information and pictures.The content was a lot, that's why instead of creating 200 single activities for very page I create one base activity which content I'm changing everytime depends on which listview item is clicked using putExtra(); and getExtra();. So the problem now is that they want me to create Favourites page, where the users can save some of the information and access them on a single activity.Actually it's really easy to do this using sqlite,but they want from me to finish the application today, within a few hours.My problem is that If i start coding it again and insert all that information in database it will take much more time for me.
So here is a little more explanation :
1.I have base activity with a listview.
2.When user click on listview item I send the content using putExtra in base activity.
So I need to learn how to save the id of listview item or something else and show that content in new Activity. I was thinking of using SharedPreferences but not really sure how to deal with that.
Any suggestions how I can do that...for a few hours.
Thanks in advance!
What kind of content is it? Is it over 200 entries and you don't save them locally?
Just knowing if it's a favorite or not can not be more than one hour job using sqlite. Just keep the id of the content and then a value to see if it's a favorite or not.
Noone will really do that for you since it's obviously your (paid?) job. The fact that you can't do it in time is really not a reason to skip the best option to use.
I would say don't be that optimistic about what you can achieve in which time. Manage your resources better and you will not have that problem.
You can achieve this with sharedpreferences too,but it's not a good idea.
The best way is to do it with database,but it's up to you.