Anyone have experience using FileSavePicker?

[DaveGx]

As Im still very much a beginner, Im having some trouble trying to get the FileSavePicker to work. Essentially, I don't see how you code the source of your file. Ive downloaded a sample, but the sample doesnt contain a real example...its not coded to save an actual file. So its not helping me much. Ive obtain a little help from MSDN, but still stuck. The Save To option comes up in my app, but when I save the file, its basically blank. Shows as 0 bytes.

So obviously I am not coding the source of the file to be saved correctly. The bold parts below is where I thought id put the code for the file source but its not right at all

namespace xxxxxx.ViewModels
{
    public class SoundData : ViewModelBase
    {
        public string Title { get; set; }
        public string FilePath { get; set; }

               

        public RelayCommand<string> SaveSoundAs { get; set; }

        private void ExecuteSaveSoundAs(string soundPath)
        {
            App.Current.RootVisual.Dispatcher.BeginInvoke(() =>
                {
                    FileSavePicker savePicker = new FileSavePicker();
                    savePicker.SuggestedStartLocation = PickerLocationId.Downloads;
                    savePicker.FileTypeChoices.Add("MP3", new List<string>() { ".mp3" });
                    [B]savePicker.ContinuationData.Add("appdata:/x.mp3", soundPath);[/B]
                    savePicker.PickSaveFileAndContinue();
                    
                }
            );
        }
        
        public async void ContinueFileSavePicker(FileSavePickerContinuationEventArgs args)
        {
            [B]string soundPath = (string)args.ContinuationData["SourceSound"];[/B]
            StorageFile file = args.File;
            if (file != null)
            {
                // Prevent updates to the remote version of the file until we finish making changes and call CompleteUpdatesAsync.
                CachedFileManager.DeferUpdates(file);
                // write to file
                await FileIO.WriteTextAsync(file, file.Name);
                // Let Windows know that we're finished changing the file so the other app can update the remote version of the file.
                // Completing updates may require Windows to ask for user input.
                FileUpdateStatus status = await CachedFileManager.CompleteUpdatesAsync(file);
                if (status == FileUpdateStatus.Complete) ;
                
                
            }
        }
            
        

    public SoundData()
        {
            SaveSoundAs = new RelayCommand<string>(ExecuteSaveSoundAs);
        }

       

    }
}

 

[Arkadiusz Szechlicki]

First place to look always should be documentation:
FileSavePicker class (Windows)

There is description of this class and example of usage