ApplicationDataCompositeValue的大小

Question

我将我在Windows Phone中发布的应用程序移植到Win 8.在尝试写入IsolatedStorage等效文件时 ApplicationDataContainer,我得到了一个例外.例外说

错误:状态管理器设置的大小已超出限制

我不确定这是否是使用的正确方法ApplicationDataContainer.

public void WriteToIsolatedStorage()
    {
        try
        {

            ApplicationDataContainer localSettings = ApplicationData.Current.LocalSettings;
            ApplicationDataCompositeValue composite = new ApplicationDataCompositeValue();

            if (localSettings.Containers.ContainsKey("LoveCycleSetting"))
            {
                localSettings.DeleteContainer("LoveCycleSetting");
            }

            composite["GetWeekStart"] = m_bWeekStart;

            composite["iHistCount"] = m_iHistCount;

            composite["dtHistory"] = this.DateTimeToString(m_dtHistory);

            composite["avgCycleTime"] = m_iAvgCycleTime;
       }
    }

例外发生在倒数第二行.m_dtHistory是一个大小为400的字符串数组.那么它ApplicationDataCompositeValue有一个固定的大小吗？或者我必须将m_dtHistory数组写入文件？在WindowsPhone中我可以直接将数组写入IsolatedStorageSettings.

如果有人可以指导我或提供链接,那将是非常有帮助的.

Alfah

Answer 1

是的,具有讽刺意味的是,手机上的设置存储比WinRT更容易.您只需序列化为文件即可.这是我所做的(部分从已经存在的代码中复制而来SuspensionManager.cs),它适用于值和引用类型.

    internal static async Task<bool> SaveSetting(string Key, Object value)
    {
        var ms = new MemoryStream();
        DataContractSerializer serializer = new DataContractSerializer(value.GetType());
        serializer.WriteObject(ms, value);
        await ms.FlushAsync();

        // Uncomment this to preview the contents being written
        /*char[] buffer = new char[ms.Length];
        ms.Seek(0, SeekOrigin.Begin);
        var sr = new StreamReader(ms);
        sr.Read(buffer, 0, (int)ms.Length);*/

        ms.Seek(0, SeekOrigin.Begin);
        StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync(Key, CreationCollisionOption.ReplaceExisting);
        using (Stream fileStream = await file.OpenStreamForWriteAsync())
        {
            await ms.CopyToAsync(fileStream);
            await fileStream.FlushAsync();
        }
        return true;
    }

    // Necessary to pass back both the result and status from an async function since you  can't pass by ref
    internal class ReadResults
    {
        public bool Success { get; set; }
        public Object Result { get; set; }
    }
    internal async static Task<ReadResults> ReadSetting<type>(string Key, Type t)
    {
        var rr = new ReadResults();

        try
        {
            var ms = new MemoryStream();
            DataContractSerializer serializer = new DataContractSerializer(t);

            StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync(Key);
            using (IInputStream inStream = await file.OpenSequentialReadAsync())
            {
                rr.Result = (type)serializer.ReadObject(inStream.AsStreamForRead());
            }
            rr.Success = true;  
        }
        catch (FileNotFoundException)
        {
            rr.Success = false;
        }
        return rr;
    }