PickAndContinue is the only method that would work on Windows Phone 8.1. It's not so weird and ugly, here goes a simple example without ContinuationManager:
Let's assume that you want to pick a .jpg file, you use FileOpenPicker:
FileOpenPicker picker = new FileOpenPicker();
picker.FileTypeFilter.Add(".jpg");
picker.ContinuationData.Add("keyParameter", "Parameter"); // some data which you can pass
picker.PickSingleFileAndContinue();
Once you run PickSingleFileAndContinue();
, your app is deactivated. When you finish picking a file, then OnActivated
event is fired, where you can read the file(s) you have picked:
protected async override void OnActivated(IActivatedEventArgs args)
{
var continuationEventArgs = args as IContinuationActivatedEventArgs;
if (continuationEventArgs != null)
{
switch (continuationEventArgs.Kind)
{
case ActivationKind.PickFileContinuation:
FileOpenPickerContinuationEventArgs arguments = continuationEventArgs as FileOpenPickerContinuationEventArgs;
string passedData = (string)arguments.ContinuationData["keyParameter"];
StorageFile file = arguments.Files.FirstOrDefault(); // your picked file
// do what you want
break;
// rest of the code - other continuation, window activation etc.
Note that when you run file picker, your app is deactivated and in some rare situations it can be terminated by OS (little resources for example).
The ContinuationManager is only a helper that should help to make some things easier. Of course, you can implement your own behaviour for simpler cases.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…