Xamarin - Working with threads

Mobile devices are optimised to run complex tasks on multiple threads. Running any form of complex task on the UI thread (the main thread) will cause the UI of your application to hang (or at least seem to anyway) until the operation is complete. The fix is to run the task on another thread and return a result back to the UI thread.

So if you find your aplication seemingly becoming unresponsive whilst running a complex or long running task like fetching a user profile from the web, then remember, run it in another thread and have a think about what other opperations can be pushed to another thread. The performance improvement is worthwhile too, since most new phones hitting the market have at least four CPU cores (some even come with eight!) the phone is more than capable of running multiple tasks at once. Your users will be thanking you too.

So running something on another thread is simple enough, simply make a new task...

Task.Run(async () =>
{
    // Run code here
})

Now if you add your code to a new task, it'll run on another thread. Just be aware that if you want to effect anything in the UI from this thread, the system will prevent this and throw an exception. To get around this, you'll need to add another small piece of code that will execute the UI action on the UI thread, here's how:

Device.BeginInvokeOnMainThread(() =>
{
    // UI interaction goes here
});

That's pretty much it. Almost anything can be run inside another thread. Here's an example of everything together so c=you can see how it's constructed:

Task.Run(async () =>
{
    // Run code here

    Device.BeginInvokeOnMainThread(() =>
    {
        // UI interaction goes here
    });
})

Good luck!


Published at

Tags: Xamarin,C#,Multi Tasking

Luke Alderton

Comments

praveen
Nice article, I have a doubt in task.run is it run asynchronously
05/10/2018
Post a comment
Sit tight...
We're adding your comment.
Thank you.
Your comment has been added.
There's been a problem.
Please try again later.
Share with
Tags
Latest Comments
By Josh on Using Umbraco Route Hijacking and posting to it
14 Jan 2019, 15:17 PM
By Shane on Xamarin Forms multiple instances of same app open
14 Dec 2018, 05:33 AM
By Daler on Xamarin MasterDetailPage has large margin/padding at top
3 Dec 2018, 06:30 AM
By JM on Solved: You need to use a Theme.AppCompat theme (or descendant) with this activity
10 Oct 2018, 13:36 PM
By praveen on Xamarin Forms - Working with threads
5 Oct 2018, 12:05 PM
By Lee Messenger on Umbraco Get Current Member or Member By ID
4 Sep 2018, 10:57 AM
By Naufil on How to open a modal window for a custom datatype in the Umbraco back office
30 Jul 2018, 12:40 PM
By Trevor on Replacing the Xamarin Header/Navigation bar with a custom view/template
19 Jul 2018, 18:36 PM
Categories
App Development
Event
Game Development
Mapping
Modelling
Programming
Review
Robotics
Tutorial
Web Development