当然是。我在app 中将文件（PDF/图像）上传到我的数据库。我的模型对象实际上将文件存储为字节数组，但对于其他函数，我必须在流之间进行转换，所以我确信将其保持为流格式同样容易。
以下是我的应用程序中的一些代码示例（复制粘贴）-
File 用于移动文件（PDF/图像）的对象：
public class File : CustomValidation, IModelBusinessObject
{
public int ID { get; set; }
public string MimeType { get; set; }
public byte[] Data { get; set; }
public int Length { get; set; }
public string MD5Hash { get; set; }
public string UploadFileName { get; set; }
}
..PdfDoc 类型专门用于 PDF 文件：
public class PdfDoc : File
{
public int ID { get; set; }
public int FileID
{
get { return base.ID; }
set { base.ID = value; }
}
[StringLength(200, ErrorMessage = "The Link Text must not be longer than 200 characters")]
public string LinkText { get; set; }
public PdfDoc() { }
public PdfDoc(File file)
{
MimeType = file.MimeType;
Data = file.Data;
Length = file.Length;
MD5Hash = file.MD5Hash;
UploadFileName = file.UploadFileName;
}
public PdfDoc(File file, string linkText)
{
MimeType = file.MimeType;
Data = file.Data;
Length = file.Length;
MD5Hash = file.MD5Hash;
UploadFileName = file.UploadFileName;
LinkText = linkText;
}
}
.. 接收文件上传的多部分 POST 的操作示例：
//
// POST: /Announcements/UploadPdfToAnnouncement/ID
[KsisAuthorize(Roles = "Admin, Announcements")]
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult UploadPdfToAnnouncement(int ID)
{
FileManagerController.FileUploadResultDTO files =
FileManagerController.GetFilesFromRequest((HttpContextWrapper)HttpContext);
if (String.IsNullOrEmpty(files.ErrorMessage) && files.TotalBytes > 0)
{
// add SINGLE file to the announcement
try
{
this._svc.AddAnnouncementPdfDoc(
this._svc.GetAnnouncementByID(ID),
new PdfDoc(files.Files[0]),
new User() { UserName = User.Identity.Name });
}
catch (ServiceExceptions.KsisServiceException ex)
{
// only handle our exceptions
base.AddErrorMessageLine(ex.Message);
}
}
// redirect back to detail page
return RedirectToAction("Detail", "Announcements", new { id = ID });
}
现在您可以在此处看到我将文件对象传递给我的服务，但您可以选择将其添加到会话并将 id 传递回“预览”视图。
最后，这是我用来将文件呈现给客户端的通用操作（您可以使用类似的东西从 Session 中呈现文件/流）：
//
// GET: /FileManager/GetFile/ID
[OutputCache(Order = 2, Duration = 600, VaryByParam = "ID")]
public ActionResult GetFile(int ID)
{
FileService svc = ObjectFactory.GetInstance<FileService>();
KsisOnline.Data.File result = svc.GetFileByID(ID);
return File(result.Data, result.MimeType, result.UploadFileName);
}
编辑：
我注意到我需要更多示例来解释上述内容-
对于上面的上传操作，FileUploadResultDTO 类：
public class FileUploadResultDTO
{
public List<File> Files { get; set; }
public Int32 TotalBytes { get; set; }
public string ErrorMessage { get; set; }
}
还有GetFilesFromRequest 函数：
public static FileUploadResultDTO GetFilesFromRequest(HttpContextWrapper contextWrapper)
{
FileUploadResultDTO result = new FileUploadResultDTO();
result.Files = new List<File>();
foreach (string file in contextWrapper.Request.Files)
{
HttpPostedFileBase hpf = contextWrapper.Request.Files[file] as HttpPostedFileBase;
if (hpf.ContentLength > 0)
{
File tempFile = new File()
{
UploadFileName = Regex.Match(hpf.FileName, @"(/|\\)?(?<fileName>[^(/|\\)]+)$").Groups["fileName"].ToString(), // to trim off whole path from browsers like IE
MimeType = hpf.ContentType,
Data = FileService.ReadFully(hpf.InputStream, 0),
Length = (int)hpf.InputStream.Length
};
result.Files.Add(tempFile);
result.TotalBytes += tempFile.Length;
}
}
return result;
}
最后（我希望我现在拥有你需要的一切）这个ReadFully 函数。这不是我的设计。我是从网上得到的——流式阅读可能很棘手。我发现这个函数是完全读取流的最成功的方法：
/// <summary>
/// Reads data from a stream until the end is reached. The
/// data is returned as a byte array. An IOException is
/// thrown if any of the underlying IO calls fail.
/// </summary>
/// <param name="stream">The stream to read data from</param>
/// <param name="initialLength">The initial buffer length</param>
public static byte[] ReadFully(System.IO.Stream stream, long initialLength)
{
// reset pointer just in case
stream.Seek(0, System.IO.SeekOrigin.Begin);
// If we've been passed an unhelpful initial length, just
// use 32K.
if (initialLength < 1)
{
initialLength = 32768;
}
byte[] buffer = new byte[initialLength];
int read = 0;
int chunk;
while ((chunk = stream.Read(buffer, read, buffer.Length - read)) > 0)
{
read += chunk;
// If we've reached the end of our buffer, check to see if there's
// any more information
if (read == buffer.Length)
{
int nextByte = stream.ReadByte();
// End of stream? If so, we're done
if (nextByte == -1)
{
return buffer;
}
// Nope. Resize the buffer, put in the byte we've just
// read, and continue
byte[] newBuffer = new byte[buffer.Length * 2];
Array.Copy(buffer, newBuffer, buffer.Length);
newBuffer[read] = (byte)nextByte;
buffer = newBuffer;
read++;
}
}
// Buffer is now too big. Shrink it.
byte[] ret = new byte[read];
Array.Copy(buffer, ret, read);
return ret;
}