Question

Can I use the ContactPicker contract when the app is snapped?

var picker = new Windows.ApplicationModel.Contacts.ContactPicker();
picker.CommitButtonText = "Select";
picker.SelectionMode = Windows.ApplicationModel.Contacts.ContactSelectionMode.Fields;
picker.DesiredFields.Add(Windows.ApplicationModel.Contacts.KnownContactField.Email);
var contactInformation = await picker.PickSingleContactAsync();

The above code works when in fullscreen but throws the following exception on the call to PickSingleContactAsync() when snapped to the side of the screen:

System.Runtime.InteropServices.COMException was unhandled by user code

HResult=-2147467259

Message=Error HRESULT E_FAIL has been returned from a call to a COM component.

Source=mscorlib

ErrorCode=-2147467259

StackTrace:
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at TouchToneDtmf.MainPage.d__e.MoveNext()
in
d:\Users\Foo\MainPage.xaml.cs:line
556 InnerException:

Answer 1

It’s not working when the app is snapped – you should check the visual state of the app before calling the ContactPicker.

In the official C# sample there is also method EnsureUnsnapped() you might find helpful when implementing this contract.

Every time you call a file[/contact] picker you must first make sure that your
app can show the file[/contact] picker by verifying that your app in not snapped
or, if your app is snapped, that it can be unsnapped in order to show
the file picker. Source – How to save files through file pickers

using Windows.UI.ViewManagement;
//...
internal bool EnsureUnsnapped()
{
    bool unsnapped = ((ApplicationView.Value != ApplicationViewState.Snapped) || ApplicationView.TryUnsnap());
    return unsnapped;
}