Forum Xamarin.Android

Timers and Screen refresh

DanDickersonDanDickerson USMember ✭✭
edited August 2017 in Xamarin.Android

I have an app that communicates with and monitors external hardware. (I am porting this from a Windows Store app)

My app consists of several screen fragments.

In my MainActivity, I created a System.Threading.Timer that is called every 100ms and handles the communications. [In the store app, this routine also updates various fields in the display.] In Xamarin.Android, when I tried to update the screen in this handler, I got an exception stating that "Only the original thread that created a view hierarchy can touch its views."

I solved this by adding a System.Timers.Timer to my MainScreenFragment that is called every second to update the screen. This appeared to work, in that I could set a breakpoint and see that the field values were being changed. But in practice, the only time the screen was updated was when I touched or otherwise interacted with it. Also, not all fields were updated each tick.

There are about 50 fields that need to be updated.

How can I force the screen to update each second? I tried calling View.RefreshDrawableState() in my timer dispatch, but that did not seem to change anything.

I looked at MVVMLight to see if binding the fields to the data might work, but it did not look like it would do what I needed. Does binding get me anything over my routine to manually update the fields, or is the overhead too high? Is there another way to implement data binding that would do the trick?

Any suggestions? All help is appreciated.


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