错误等待操作员。正确实施，但不起作用

Question

我尝试创建一个文件 select 并需要列表文件。我正在使用 await 运算符，但不起作用。

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    base.OnNavigatedTo(e);

    StorageFolder folder = KnownFolders.MusicLibrary;

    List<StorageFile> listOfFiles = new List<StorageFile>();
    await RetriveFilesInFolders(listOfFiles, folder);
    // as a result of above code I have a List of 5 files that are in Music Library

    List<IStorageItem> filesFolders = (await folder.GetItemsAsync()).ToList();
    List<StorageFile> items = (await folder.GetFilesAsync(CommonFileQuery.OrderByName)).ToList();

}

private async Task RetriveFilesInFolders(List<StorageFile> list, StorageFolder parent)
{
    foreach (var item in await parent.GetFilesAsync()) list.Add(item);
    foreach (var item in await parent.GetFoldersAsync()) await RetriveFilesInFolders(list, item);
}

和 Visual Studio 节目

The 'await' operator can only be used within an async method. Consider marking this method with the 'async' modifier and changing its return type to 'Task'

Answer 1

您在 OnNavigatedTo 方法中使用了 await 运算符，该方法未使用 async 修饰符标记为异步。 我想你得到的信息已经很清楚了。