CopySync方法在我的应用程序中不起作用

我在微软找到了大量关于这个方法的信息,所以我知道这是可能的。我对用C#构建应用程序是全新的,所以我不太确定如何修复它。

我的代码如下:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;
using Windows.Storage;

namespace MusicLibraryTest

{

public static class LibraryHelper

{

    public static async void ChooseMusic()

    {

        //Music Library is opened on user's computer and displays all available mp3 files

        var picker = new Windows.Storage.Pickers.FileOpenPicker
        {
            ViewMode = Windows.Storage.Pickers.PickerViewMode.Thumbnail,
            SuggestedStartLocation =
        Windows.Storage.Pickers.PickerLocationId.MusicLibrary
        };

        picker.FileTypeFilter.Add(".mp3");

        //File is copied to local folder for use in music library
        var file = picker.PickSingleFileAsync();
        if (file != null)
        {
            await file.CopyAsync(ApplicationData.Current.LocalFolder);
        }
    }