How to Simulate or Trigger Enter or Return key programmatically in Xamarin.Forms

Question

I have a camera scanner app that scans barcodes and the result is returned to an Entry field.

I can focus that Entry field but I can't get it to press enter programmatically, is there a way to do this in Xamarin.Forms?

My Target platform is Android.

Answer 1

this is a small replication of the problem, which is fairly simple.

in XAML:

<Entry Name="entry" Completed="OnCompleted"/>
<Label Name="label"/>
<Button Text="PRESS ENTER" Clicked="OnButtonPressed"/>

in C# or code behind I have:

void OnCompleted(object sender, EventArgs e) 
{
    label.Text = entry.Text;
}

void OnButtonPressed (object sender, EventArgs e)
{
    // we will be adding this code here at the last step
}

then create an Interface because the only easy way to do this is by using the native android functionality through a DependencyService:

public Interface IEnterService
{
    void PressEnter();
}

Then in the Android Project you need to create a class for example: EnterService and implement the previous created interface like this:

[assembly: Xamarin.Forms.Dependency(typeof(EnterService))]
namespace TestEnterPressed.Droid
{
    [Register("sendKeyDownUpSync", "(I)V", "GetSendKeyDownUpSync_IHandler")]
    class EnterService : IEnterService
    {
        public void PressEnter()
        {
            Console.WriteLine("ENTER IS PRESSED");
            Instrumentation inst = new Instrumentation();
            new Thread(() =>
            {
                Thread.CurrentThread.IsBackground = true;
                
                /* run your code here */
                inst.SendKeyDownUpSync(Keycode.Enter);
            }).Start();
        }
    }
}

Then in the last step use your DependencyService to simulate Enter pressed through a button other than the keyboard or after scanning a barcode with a camera you can do it like this:

void OnButtonPressed(object sender, EventArgs e)
{
    entry.Focus();
    DependencyService.Get<IEnterService>().PressEnter();
}

I hope this is useful to somebody, thanks a bunch everyone :)