从窗口应用商店应用中的任务检索数据

Question

我正在使用此方法在我的应用程序中序列化和反序列化 ObservableCollections。

        public static async void SaveToXmlAsync(string fileName, T classInstanceToSave)
    {
        using (var stream = await ApplicationData.Current.LocalFolder.OpenStreamForWriteAsync(fileName, CreationCollisionOption.ReplaceExisting))
        {
            XmlSerializer serializer = new XmlSerializer(typeof(T));
            using (XmlWriter xmlWriter = XmlWriter.Create(stream, new XmlWriterSettings() { Indent = true }))
            {
                serializer.Serialize(xmlWriter, classInstanceToSave);
            }
        }
    }
    public static async System.Threading.Tasks.Task<T> LoadFromXmlAsync(string fileName)
    {
        try
        {
            var files = ApplicationData.Current.LocalFolder.GetFilesAsync(Windows.Storage.Search.CommonFileQuery.OrderByName).GetResults();
            var file = files.FirstOrDefault(f => f.Name == fileName);
            // If the file exists, try and load it it's data.
            if (file != null)
            {
                using (var stream = await ApplicationData.Current.LocalFolder.OpenStreamForReadAsync(fileName))
                {
                    XmlSerializer serializer = new XmlSerializer(typeof(T));
                    T data = (T)serializer.Deserialize(stream);
                    return data;
                }
            }
        }
        // Eat any exceptions unless debugging so that users don't see any errors.
        catch
        {
            if (IsDebugging)
                throw;
        }
        // We couldn't load the data, so just return a default instance of the class.
        return default(T);
    }
}

我在该主题中找到了此方法：单击我

而且我不知道如何读取保存的数据。如何将从反序列化程序方法返回的任务强制转换为我的集合？我试过了，但它无法编译：

ObservableCollection<Product> collection = Toolkit<ObservableCollection<Product>>.LoadFromXmlAsync("list1.xml");

Answer 1

ObservableCollection<Product> collection = await Toolkit<ObservableCollection<Product>>.LoadFromXmlAsync("list1.xml");

还将异步关键字放入您自己的方法中。

祝你好运