（前言：这个问题是关于2011年发布的ASP.NET MVC 3.0，而不是关于2019年发布的ASP.NETCore 3.0）
我想用asp.net mvc上传文件。如何使用html输入文件控件上载文件？
当前回答
另一种传输到字节[]的方法（用于保存到DB）。
@Arthur的方法工作得很好，但不能完美复制，因此MS Office文档在从数据库检索后可能无法打开。MemoryStream.GetBuffer（）可以在字节[]的末尾返回额外的空字节，但可以使用MemoryStream.ToArray（）来解决这个问题。然而，我发现这个替代方案可以完美地适用于所有文件类型：
using (var binaryReader = new BinaryReader(file.InputStream))
{
byte[] array = binaryReader.ReadBytes(file.ContentLength);
}
这是我的完整代码：
文档类别：
public class Document
{
public int? DocumentID { get; set; }
public string FileName { get; set; }
public byte[] Data { get; set; }
public string ContentType { get; set; }
public int? ContentLength { get; set; }
public Document()
{
DocumentID = 0;
FileName = "New File";
Data = new byte[] { };
ContentType = "";
ContentLength = 0;
}
}
文件下载：
[HttpGet]
public ActionResult GetDocument(int? documentID)
{
// Get document from database
var doc = dataLayer.GetDocument(documentID);
// Convert to ContentDisposition
var cd = new System.Net.Mime.ContentDisposition
{
FileName = doc.FileName,
// Prompt the user for downloading; set to true if you want
// the browser to try to show the file 'inline' (display in-browser
// without prompting to download file). Set to false if you
// want to always prompt them to download the file.
Inline = true,
};
Response.AppendHeader("Content-Disposition", cd.ToString());
// View document
return File(doc.Data, doc.ContentType);
}
文件上载：
[HttpPost]
public ActionResult GetDocument(HttpPostedFileBase file)
{
// Verify that the user selected a file
if (file != null && file.ContentLength > 0)
{
// Get file info
var fileName = Path.GetFileName(file.FileName);
var contentLength = file.ContentLength;
var contentType = file.ContentType;
// Get file data
byte[] data = new byte[] { };
using (var binaryReader = new BinaryReader(file.InputStream))
{
data = binaryReader.ReadBytes(file.ContentLength);
}
// Save to database
Document doc = new Document()
{
FileName = fileName,
Data = data,
ContentType = contentType,
ContentLength = contentLength,
};
dataLayer.SaveDocument(doc);
// Show success ...
return RedirectToAction("Index");
}
else
{
// Show error ...
return View("Foo");
}
}
视图（代码段）：
@using (Html.BeginForm("GetDocument", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" name="file" />
<input type="submit" value="Upload File" />
}
其他回答
要传输到字节[]（例如，用于保存到DB）：
using (MemoryStream ms = new MemoryStream()) {
file.InputStream.CopyTo(ms);
byte[] array = ms.GetBuffer();
}
若要将输入流直接传输到数据库中，而不将其存储在内存中，您可以使用从此处获取的此类，并稍作更改：
public class VarbinaryStream : Stream {
private SqlConnection _Connection;
private string _TableName;
private string _BinaryColumn;
private string _KeyColumn;
private int _KeyValue;
private long _Offset;
private SqlDataReader _SQLReader;
private long _SQLReadPosition;
private bool _AllowedToRead = false;
public VarbinaryStream(
string ConnectionString,
string TableName,
string BinaryColumn,
string KeyColumn,
int KeyValue,
bool AllowRead = false)
{
// create own connection with the connection string.
_Connection = new SqlConnection(ConnectionString);
_TableName = TableName;
_BinaryColumn = BinaryColumn;
_KeyColumn = KeyColumn;
_KeyValue = KeyValue;
// only query the database for a result if we are going to be reading, otherwise skip.
_AllowedToRead = AllowRead;
if (_AllowedToRead == true)
{
try
{
if (_Connection.State != ConnectionState.Open)
_Connection.Open();
SqlCommand cmd = new SqlCommand(
@"SELECT TOP 1 [" + _BinaryColumn + @"]
FROM [dbo].[" + _TableName + @"]
WHERE [" + _KeyColumn + "] = @id",
_Connection);
cmd.Parameters.Add(new SqlParameter("@id", _KeyValue));
_SQLReader = cmd.ExecuteReader(
CommandBehavior.SequentialAccess |
CommandBehavior.SingleResult |
CommandBehavior.SingleRow |
CommandBehavior.CloseConnection);
_SQLReader.Read();
}
catch (Exception e)
{
// log errors here
}
}
}
// this method will be called as part of the Stream ímplementation when we try to write to our VarbinaryStream class.
public override void Write(byte[] buffer, int index, int count)
{
try
{
if (_Connection.State != ConnectionState.Open)
_Connection.Open();
if (_Offset == 0)
{
// for the first write we just send the bytes to the Column
SqlCommand cmd = new SqlCommand(
@"UPDATE [dbo].[" + _TableName + @"]
SET [" + _BinaryColumn + @"] = @firstchunk
WHERE [" + _KeyColumn + "] = @id",
_Connection);
cmd.Parameters.Add(new SqlParameter("@firstchunk", buffer));
cmd.Parameters.Add(new SqlParameter("@id", _KeyValue));
cmd.ExecuteNonQuery();
_Offset = count;
}
else
{
// for all updates after the first one we use the TSQL command .WRITE() to append the data in the database
SqlCommand cmd = new SqlCommand(
@"UPDATE [dbo].[" + _TableName + @"]
SET [" + _BinaryColumn + @"].WRITE(@chunk, NULL, @length)
WHERE [" + _KeyColumn + "] = @id",
_Connection);
cmd.Parameters.Add(new SqlParameter("@chunk", buffer));
cmd.Parameters.Add(new SqlParameter("@length", count));
cmd.Parameters.Add(new SqlParameter("@id", _KeyValue));
cmd.ExecuteNonQuery();
_Offset += count;
}
}
catch (Exception e)
{
// log errors here
}
}
// this method will be called as part of the Stream ímplementation when we try to read from our VarbinaryStream class.
public override int Read(byte[] buffer, int offset, int count)
{
try
{
long bytesRead = _SQLReader.GetBytes(0, _SQLReadPosition, buffer, offset, count);
_SQLReadPosition += bytesRead;
return (int)bytesRead;
}
catch (Exception e)
{
// log errors here
}
return -1;
}
public override bool CanRead
{
get { return _AllowedToRead; }
}
protected override void Dispose(bool disposing)
{
if (_Connection != null)
{
if (_Connection.State != ConnectionState.Closed)
try { _Connection.Close(); }
catch { }
_Connection.Dispose();
}
base.Dispose(disposing);
}
#region unimplemented methods
public override bool CanSeek
{
get { return false; }
}
public override bool CanWrite
{
get { return true; }
}
public override void Flush()
{
throw new NotImplementedException();
}
public override long Length
{
get { throw new NotImplementedException(); }
}
public override long Position
{
get
{
throw new NotImplementedException();
}
set
{
throw new NotImplementedException();
}
}
public override long Seek(long offset, SeekOrigin origin)
{
throw new NotImplementedException();
}
public override void SetLength(long value)
{
throw new NotImplementedException();
}
#endregion unimplemented methods }
以及用法：
using (var filestream = new VarbinaryStream(
"Connection_String",
"Table_Name",
"Varbinary_Column_name",
"Key_Column_Name",
keyValueId,
true))
{
postedFile.InputStream.CopyTo(filestream);
}
我的方法和上面差不多，我将向您展示我的代码以及如何使用MYSSQL数据库。。。
数据库中的文档表-
int Id（PK），字符串Url，字符串描述，创建者，租户ID上传日期
上面的代码ID是主键，URL是文件的名称（末尾有文件类型），要在文档视图中输出的文件描述，CreatedBy是上载文件的人，tenncyId，dateUploaded
在视图中，必须定义enctype，否则它将无法正常工作。
@using (Html.BeginForm("Upload", "Document", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<div class="input-group">
<label for="file">Upload a document:</label>
<input type="file" name="file" id="file" />
</div>
}
上面的代码将给你一个浏览按钮，然后在我的项目中，我有一个基本上名为IsValidImage的类，它只是检查文件大小是否在指定的最大大小之下，检查它是否是IMG文件，这都在类bool函数中。所以，如果true返回true。
public static bool IsValidImage(HttpPostedFileBase file, double maxFileSize, ModelState ms )
{
// make sur the file isnt null.
if( file == null )
return false;
// the param I normally set maxFileSize is 10MB 10 * 1024 * 1024 = 10485760 bytes converted is 10mb
var max = maxFileSize * 1024 * 1024;
// check if the filesize is above our defined MAX size.
if( file.ContentLength > max )
return false;
try
{
// define our allowed image formats
var allowedFormats = new[] { ImageFormat.Jpeg, ImageFormat.Png, ImageFormat.Gif, ImageFormat.Bmp };
// Creates an Image from the specified data stream.
using (var img = Image.FromStream(file.InputStream))
{
// Return true if the image format is allowed
return allowedFormats.Contains(img.RawFormat);
}
}
catch( Exception ex )
{
ms.AddModelError( "", ex.Message );
}
return false;
}
因此，在控制器中：
if (!Code.Picture.IsValidUpload(model.File, 10, true))
{
return View(model);
}
// Set the file name up... Being random guid, and then todays time in ticks. Then add the file extension
// to the end of the file name
var dbPath = Guid.NewGuid().ToString() + DateTime.UtcNow.Ticks + Path.GetExtension(model.File.FileName);
// Combine the two paths together being the location on the server to store it
// then the actual file name and extension.
var path = Path.Combine(Server.MapPath("~/Uploads/Documents/"), dbPath);
// set variable as Parent directory I do this to make sure the path exists if not
// I will create the directory.
var directoryInfo = new FileInfo(path).Directory;
if (directoryInfo != null)
directoryInfo.Create();
// save the document in the combined path.
model.File.SaveAs(path);
// then add the data to the database
_db.Documents.Add(new Document
{
TenancyId = model.SelectedTenancy,
FileUrl = dbPath,
FileDescription = model.Description,
CreatedBy = loggedInAs,
CreatedDate = DateTime.UtcNow,
UpdatedDate = null,
CanTenantView = true
});
_db.SaveChanges();
model.Successfull = true;
public ActionResult FileUpload(upload mRegister) {
//Check server side validation using data annotation
if (ModelState.IsValid) {
//TO:DO
var fileName = Path.GetFileName(mRegister.file.FileName);
var path = Path.Combine(Server.MapPath("~/Content/Upload"), fileName);
mRegister.file.SaveAs(path);
ViewBag.Message = "File has been uploaded successfully";
ModelState.Clear();
}
return View();
}
另一种传输到字节[]的方法（用于保存到DB）。
@Arthur的方法工作得很好，但不能完美复制，因此MS Office文档在从数据库检索后可能无法打开。MemoryStream.GetBuffer（）可以在字节[]的末尾返回额外的空字节，但可以使用MemoryStream.ToArray（）来解决这个问题。然而，我发现这个替代方案可以完美地适用于所有文件类型：
using (var binaryReader = new BinaryReader(file.InputStream))
{
byte[] array = binaryReader.ReadBytes(file.ContentLength);
}
这是我的完整代码：
文档类别：
public class Document
{
public int? DocumentID { get; set; }
public string FileName { get; set; }
public byte[] Data { get; set; }
public string ContentType { get; set; }
public int? ContentLength { get; set; }
public Document()
{
DocumentID = 0;
FileName = "New File";
Data = new byte[] { };
ContentType = "";
ContentLength = 0;
}
}
文件下载：
[HttpGet]
public ActionResult GetDocument(int? documentID)
{
// Get document from database
var doc = dataLayer.GetDocument(documentID);
// Convert to ContentDisposition
var cd = new System.Net.Mime.ContentDisposition
{
FileName = doc.FileName,
// Prompt the user for downloading; set to true if you want
// the browser to try to show the file 'inline' (display in-browser
// without prompting to download file). Set to false if you
// want to always prompt them to download the file.
Inline = true,
};
Response.AppendHeader("Content-Disposition", cd.ToString());
// View document
return File(doc.Data, doc.ContentType);
}
文件上载：
[HttpPost]
public ActionResult GetDocument(HttpPostedFileBase file)
{
// Verify that the user selected a file
if (file != null && file.ContentLength > 0)
{
// Get file info
var fileName = Path.GetFileName(file.FileName);
var contentLength = file.ContentLength;
var contentType = file.ContentType;
// Get file data
byte[] data = new byte[] { };
using (var binaryReader = new BinaryReader(file.InputStream))
{
data = binaryReader.ReadBytes(file.ContentLength);
}
// Save to database
Document doc = new Document()
{
FileName = fileName,
Data = data,
ContentType = contentType,
ContentLength = contentLength,
};
dataLayer.SaveDocument(doc);
// Show success ...
return RedirectToAction("Index");
}
else
{
// Show error ...
return View("Foo");
}
}
视图（代码段）：
@using (Html.BeginForm("GetDocument", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" name="file" />
<input type="submit" value="Upload File" />
}
由于我在IE浏览器中发现了上传文件的问题，我建议这样处理。
View
@using (Html.BeginForm("UploadFile", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" name="file" />
<input type="submit" value="Submit" />
}
控制器
public class HomeController : Controller
{
public ActionResult UploadFile()
{
return View();
}
[HttpPost]
public ActionResult UploadFile(MyModal Modal)
{
string DocumentName = string.Empty;
string Description = string.Empty;
if (!String.IsNullOrEmpty(Request.Form["DocumentName"].ToString()))
DocumentName = Request.Form["DocumentName"].ToString();
if (!String.IsNullOrEmpty(Request.Form["Description"].ToString()))
Description = Request.Form["Description"].ToString();
if (!String.IsNullOrEmpty(Request.Form["FileName"].ToString()))
UploadedDocument = Request.Form["FileName"].ToString();
HttpFileCollectionBase files = Request.Files;
string filePath = Server.MapPath("~/Root/Documents/");
if (!(Directory.Exists(filePath)))
Directory.CreateDirectory(filePath);
for (int i = 0; i < files.Count; i++)
{
HttpPostedFileBase file = files[i];
// Checking for Internet Explorer
if (Request.Browser.Browser.ToUpper() == "IE" || Request.Browser.Browser.ToUpper() == "INTERNETEXPLORER")
{
string[] testfiles = file.FileName.Split(new char[] { '\\' });
fname = testfiles[testfiles.Length - 1];
UploadedDocument = fname;
}
else
{
fname = file.FileName;
UploadedDocument = file.FileName;
}
file.SaveAs(fname);
return RedirectToAction("List", "Home");
}
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