The touchscreen keyboard is provided by the Windows IoT operating system and needs to be enabled.

Open the web interface based “Windows Device Portal” as above and select: Device Settings > On-screen Keyboard > Set the checkbox to ticked

Make Keyboard appear

Give text box focus

txtMyTextBox.Focus(FocusState.Programmatic);

Another method (won’t always work but can be useful sometimes)

InputPane.GetForCurrentView().TryShow();

Using a hidden TextBox

You can’t set a text box to not visible and have it still take focus / text entry, but you can achieve the same thing by setting its opacity to 0:

MyTextBox.Opacity = 0;

Stopping keyboard appearing

The TextBox class has PreventKeyboardDisplayOnProgrammaticFocus property

Selecting keyboard type

Use input scope to select, e.g.

    <TextBox Header="Name" InputScope="Default"/>
    <TextBox Header="Email Address" InputScope="EmailSmtpAddress"/>
    <TextBox Header="Telephone Number" InputScope="TelephoneNumber"/>
    <TextBox Header="Web site" InputScope="Url"/>