Windows phone 7 尝试创建任何类型的文件时发出IsolatedStorageFileStream

在我的WP7项目中，

IsolatedStorageFileStream

有一个非常棘手的问题。我总是会遇到类似“操作不允许在IsolatedStorageFileStream上进行”这样的错误

这是我的代码（2个案例）：

1º：

void camera_Completed(object sender, PhotoResult e)
{
    var imageBytes = new byte[e.ChosenPhoto.Length];
    e.ChosenPhoto.Read(imageBytes, 0, imageBytes.Length);

    using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
    {
        if (!myIsolatedStorage.DirectoryExists("Fotos"))
            myIsolatedStorage.CreateDirectory("Fotos");


         IsolatedStorageFileStream fileStream = myIsolatedStorage.CreateFile("foto." + DateTime.Now.Date + "jpeg");

        BitmapImage bitmap = new BitmapImage();

          bitmap.SetSource(e.ChosenPhoto);
        WriteableBitmap wb = new WriteableBitmap(bitmap);
        Extensions.SaveJpeg(wb, fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
        fileStream.Close();
    }

    e.ChosenPhoto.Seek(0, SeekOrigin.Begin);
    imgField.Source = PictureDecoder.DecodeJpeg(e.ChosenPhoto);

    thumbnail = imageBytes;
    base64String = System.Convert.ToBase64String(imageBytes, 0, imageBytes.Length);
}

void camera_Completed(object sender, PhotoResult e)
{
    var imageBytes = new byte[e.ChosenPhoto.Length];
    e.ChosenPhoto.Read(imageBytes, 0, imageBytes.Length);

    using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
    {
        if (!myIsolatedStorage.DirectoryExists("Fotos"))
            myIsolatedStorage.CreateDirectory("Fotos");


        IsolatedStorageFileStream fileStream = new IsolatedStorageFileStream(@"Shared/foto." + DateTime.Now.Date + "jpeg", FileMode.CreateNew, myIsolatedStorage);

        BitmapImage bitmap = new BitmapImage();

        bitmap.SetSource(e.ChosenPhoto);
        WriteableBitmap wb = new WriteableBitmap(bitmap);
        Extensions.SaveJpeg(wb, fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
        fileStream.Close();
    }

    e.ChosenPhoto.Seek(0, SeekOrigin.Begin);
    imgField.Source = PictureDecoder.DecodeJpeg(e.ChosenPhoto);

    thumbnail = imageBytes;
    base64String = System.Convert.ToBase64String(imageBytes, 0, imageBytes.Length);
}

2º：

void camera_Completed(object sender, PhotoResult e)
{
    var imageBytes = new byte[e.ChosenPhoto.Length];
    e.ChosenPhoto.Read(imageBytes, 0, imageBytes.Length);

    using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
    {
        if (!myIsolatedStorage.DirectoryExists("Fotos"))
            myIsolatedStorage.CreateDirectory("Fotos");


         IsolatedStorageFileStream fileStream = myIsolatedStorage.CreateFile("foto." + DateTime.Now.Date + "jpeg");

        BitmapImage bitmap = new BitmapImage();

          bitmap.SetSource(e.ChosenPhoto);
        WriteableBitmap wb = new WriteableBitmap(bitmap);
        Extensions.SaveJpeg(wb, fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
        fileStream.Close();
    }

    e.ChosenPhoto.Seek(0, SeekOrigin.Begin);
    imgField.Source = PictureDecoder.DecodeJpeg(e.ChosenPhoto);

    thumbnail = imageBytes;
    base64String = System.Convert.ToBase64String(imageBytes, 0, imageBytes.Length);
}

void camera_Completed(object sender, PhotoResult e)
{
    var imageBytes = new byte[e.ChosenPhoto.Length];
    e.ChosenPhoto.Read(imageBytes, 0, imageBytes.Length);

    using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
    {
        if (!myIsolatedStorage.DirectoryExists("Fotos"))
            myIsolatedStorage.CreateDirectory("Fotos");


        IsolatedStorageFileStream fileStream = new IsolatedStorageFileStream(@"Shared/foto." + DateTime.Now.Date + "jpeg", FileMode.CreateNew, myIsolatedStorage);

        BitmapImage bitmap = new BitmapImage();

        bitmap.SetSource(e.ChosenPhoto);
        WriteableBitmap wb = new WriteableBitmap(bitmap);
        Extensions.SaveJpeg(wb, fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
        fileStream.Close();
    }

    e.ChosenPhoto.Seek(0, SeekOrigin.Begin);
    imgField.Source = PictureDecoder.DecodeJpeg(e.ChosenPhoto);

    thumbnail = imageBytes;
    base64String = System.Convert.ToBase64String(imageBytes, 0, imageBytes.Length);
}

---

有人能告诉我为什么这段代码不起作用吗？这个网站的一个例子是这样的：？

来自IsolatedStorage的错误消息非常有用。例如，如果您试图打开一个不存在的文件，您将收到相同的消息。在不知道异常发生在哪里的情况下，很难猜测代码中的确切问题是什么，但如果必须猜测，我会说原因是试图生成如下文件名：

@"Shared/foto." + DateTime.Now.Date + "jpeg"

---

我不确定日期是如何转换为字符串的，这取决于语言环境，但我猜它没有创建有效的文件名。

您已经给出了很多代码-哪个方法调用失败？生成的文件名是什么？它是否有任何无效字符？失败的方法调用是此行IsolatedStorageFileStream fileStream=new IsolatedStorageFileStream（@“Shared/foto.”+DateTime.Now.Date+“jpeg”、FileMode.CreateNew、myIsolatedStorage）；但是在重载方法中使用字符串名称之前，我成功地连接了字符串名称，我想这是WP7编程的问题吧？最后它工作得很好：），感谢大家的回答^^实际上它创建了一个有效的文件名，但它没有将日期与字符串的其余部分连接起来，最后它在方法中使用它之前构建了字符串文件名。