Android Question [Solved] About StartActivity

[vfafou]

Hello!
I would like to ask what happens every time we call StartActivity(ActName):

1. Previous ActName is destroyed and a new ActName is started, so garbage collector releases the previous ActName?
2. Previous ActName is simply paused and a new ActName is started?

Thank you in advance!

 

[JordiCP]

3. Starts an activity or brings it to front if already exists

(start typing it in your IDE and this will appear)

 

[vfafou]

Hello Jordi!
Thank you for your response.
I really haven't noticed that the autocomplete comment describes the functionality of StartActivity!
One more question:
What could I do to start an activity from a service? This is critical for my app functionality!
Thank you in advance!

 

[JordiCP]

Just call

StartActivity(yourActivity)

However, unless your app really requires it, usually it is better to launch a notification and let the user decide if he wants to open the app or not by clicking on it (just as gmail, whatsapp or others do)

 

[vfafou]

It is more complicated in my case:
I need to start an activity after receiving a push message, received from a service module while screen is off.

 

[JordiCP]

There are some threads regarding this.

So, if you must launch for instance your main activity, just do it from your service

StartActivity(main)

If it does not work when the screen is off, you could try this (not tested, taken from an old code where I did something similar with a transparent activity)

      Dim In As Intent
     In.Initialize("","")
     In.SetComponent("my.package.name/.my_activity_name")    '<-- for instance "b4a.example/.main"

     Dim FLAG_DISMISS_KEYGUARD as Int = 0x00400000
     Dim FLAG_TURN_SCREEN_ON as Int   = 0x00200000

     In.Flags = Bit.Or(FLAG_TURN_SCREEN_ON, FLAG_DISMISS_KEYGUARD )
       
     StartActivity(In)

 

[DonManfred]

Just call

Erel says somewhere in forum that you should not use StartActivity from a service.
Using CallSubDelayed is the right way.

 

[JordiCP]

Erel says somewhere in forum that you should not use StartActivity from a service.
Using CallSubDelayed is the right way.

You are right @DonManfred

However, I doubt (well, the exact sentence would be "I don't know at all") if CallSubDelayed will have the same effect as a Starting intent (with the corresponding flags) in case the screen is off (will try it later just out of curiosity)

 

[DonManfred]

you need to aquire a partial wakelock for this result i guess.
But i´m not sure here too.

 

[KMatle]

you need to aquire a partial wakelock for this result i guess

Yep. I've made some good experiences with it. Works good.

 

[vfafou]

Thank you all for your advices! I have already used partial wakelock to the previous version of the app I'm writing by now and it really works great!