Change integer value from another Activity

Question

I want change a value from another activity like this

Main_activity.java

...
long notify_interval = 1000; //ms
...

But, In another activity, called system.java, I have this code

btn_normal.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Main_activity.notify_interval = 1000; // HERE <<--
            Toast.makeText(getApplicationContext(), "Interval changed!", Toast.LENGTH_SHORT).show();
        }
    });

But isn't working, someone tells me that this way never will work. So, what should I do?

--------- UPDATE ---------

Hello, with this trick, I'm able to change long value between activities

 public static long notify_interval = 1000;

But, I'm using AlarmManager, when I close the app, instead of using the custom notify_interval that I set, the system is using the default value (1000). So, what should I do to fix it?

https://developer.android.com/training/data-storage/shared-preferences.html — OneCricketeer, Nov 28 '17 at 20:06
Depending on what you are trying to do, there are tons of ways to share data between activities. You could use an SQLite Database, SharedPreferences, or just hold the data in the MainActivity and send via a Bundle in the Intent. — escapesequence, Nov 28 '17 at 20:09
@escapesequence I'm getting problems with this method in this link that you mentioned. Sorry — Giuseppe, Nov 28 '17 at 20:12
The notify_internal is being called by several functions, so, I believe that it's more complex than I think, idk... — Giuseppe, Nov 28 '17 at 20:14
@cricket_007 I'm not able to use data-storage since I'm using Service as extends, I believe. — Giuseppe, Nov 28 '17 at 20:17
You only need a Context to use SharedPreferences. A Service is a Context object — OneCricketeer, Nov 28 '17 at 20:25
https://stackoverflow.com/questions/13558550/can-i-get-data-from-shared-preferences-inside-a-service — OneCricketeer, Nov 28 '17 at 20:25
However, you still need to **tell** the MainActivity that the value has changed. (Like a BroadcastReceiver) — OneCricketeer, Nov 28 '17 at 20:26

score 1 · Answer 1 · answered Nov 28 '17 at 20:14

1

If u need to do it in real-time, make interface and make activity implement it then pass it where u are updating value and call method that updates value in activity

else u need to add extra to intent

another way is to use RxJava or EventBus.

answered Nov 28 '17 at 20:14

svkaka

3,942
2
31
55

score 1 · Answer 2 · answered Nov 28 '17 at 20:36

1

You can use static variable to do that.

public static long notify_interval = 1000;

On second activity use

btn_normal.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Main_activity.notify_interval = 1000; // HERE <<--
            Toast.makeText(getApplicationContext(), "Interval changed!", Toast.LENGTH_SHORT).show();
        }
    });

Its worked fine.

answered Nov 28 '17 at 20:36

Saheb Roy

161
4

Hello! I already tried it, but the notify_interval is not being updated. Maybe it is being always used in a process. – Giuseppe Nov 28 '17 at 20:41
You take notify_interval as static variable ? – Saheb Roy Nov 28 '17 at 20:45
Yes, I already changed – Giuseppe Nov 28 '17 at 20:48
can i have your main_activity code here. – Saheb Roy Nov 28 '17 at 20:52
Here you go: https://pastebin.com/5N2w2wFx – Giuseppe Nov 28 '17 at 20:55
and second activity also – Saheb Roy Nov 28 '17 at 21:01
https://pastebin.com/g9U7nHUk – Giuseppe Nov 28 '17 at 21:03
you want to change mTimer.schedule(new TimerTaskToGetLocation(),5,notify_interval); interval time right. – Saheb Roy Nov 28 '17 at 21:05
Yes, change it! – Giuseppe Nov 28 '17 at 21:06
So my friend the mTimer.schedule was in onCreate method, which run only once. So if you change the value of notify_interval not worked over here. – Saheb Roy Nov 28 '17 at 21:10
you need to restart service after setting value to notify_interval. – Saheb Roy Nov 28 '17 at 21:10
Do you know how? – Giuseppe Nov 28 '17 at 21:12
1

create method on main_activity called restartService(){stopService(new Intent(this, GoogleService.class)); startService(new Intent(this, GoogleService.class)); } and called this every time after setting notify_interval – Saheb Roy Nov 28 '17 at 21:16
It's working, but I'm using AlarmManager, and in background mode, he's using the default notify_interval value, not the value that I changed. What should I do to solve it? – Giuseppe Nov 28 '17 at 21:43

Change integer value from another Activity

2 Answers2