（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
下面是我的工作示例：
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Create(Product product, HttpPostedFileBase file)
{
if (!ModelState.IsValid)
return PartialView("Create", product);
if (file != null)
{
var fileName = Path.GetFileName(file.FileName);
var guid = Guid.NewGuid().ToString();
var path = Path.Combine(Server.MapPath("~/Content/Uploads/ProductImages"), guid + fileName);
file.SaveAs(path);
string fl = path.Substring(path.LastIndexOf("\\"));
string[] split = fl.Split('\\');
string newpath = split[1];
string imagepath = "Content/Uploads/ProductImages/" + newpath;
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
byte[] array = ms.GetBuffer();
}
var nId = Guid.NewGuid().ToString();
// Save record to database
product.Id = nId;
product.State = 1;
product.ImagePath = imagepath;
product.CreatedAt = DateTime.Now;
db.Products.Add(product);
await db.SaveChangesAsync();
TempData["message"] = "ProductCreated";
//return RedirectToAction("Index", product);
}
// after successfully uploading redirect the user
return Json(new { success = true });
}
其他回答
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" />
}
MemoryStream.GetBuffer() can return extra empty bytes at the end of the byte[], but you can fix that by using MemoryStream.ToArray() instead. However, I found this alternative to work perfectly for all file types:
using (var binaryReader = new BinaryReader(file.InputStream))
{
byte[] array = binaryReader.ReadBytes(file.ContentLength);
}
Here's my full code:
Document Class:
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;
}
}
File Download:
[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);
}
File Upload:
[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");
}
}
View (snippet):
@using (Html.BeginForm("GetDocument", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" name="file" />
<input type="submit" value="Upload File" />
}
使用formdata上载文件
.cshtml文件
var files = $("#file").get(0).files;
if (files.length > 0) {
data.append("filekey", files[0]);}
$.ajax({
url: '@Url.Action("ActionName", "ControllerName")', type: "POST", processData: false,
data: data, dataType: 'json',
contentType: false,
success: function (data) {
var response=data.JsonData;
},
error: function (er) { }
});
服务器端代码
if (System.Web.HttpContext.Current.Request.Files.AllKeys.Any())
{
var pic = System.Web.HttpContext.Current.Request.Files["filekey"];
HttpPostedFileBase filebase = new HttpPostedFileWrapper(pic);
var fileName = Path.GetFileName(filebase.FileName);
string fileExtension = System.IO.Path.GetExtension(fileName);
if (fileExtension == ".xls" || fileExtension == ".xlsx")
{
string FileName = Guid.NewGuid().GetHashCode().ToString("x");
string dirLocation = Server.MapPath("~/Content/PacketExcel/");
if (!Directory.Exists(dirLocation))
{
Directory.CreateDirectory(dirLocation);
}
string fileLocation = Server.MapPath("~/Content/PacketExcel/") + FileName + fileExtension;
filebase.SaveAs(fileLocation);
}
}
请注意此代码仅用于上传图像。我使用HTMLHelper上传图像。在cshtml文件中放入以下代码
@using (Html.BeginForm("UploadImageAction", "Admin", FormMethod.Post, new { enctype = "multipart/form-data", id = "myUploadForm" }))
{
<div class="controls">
@Html.UploadFile("UploadImage")
</div>
<button class="button">Upload Image</button>
}
然后为Upload标记创建HTMLHelper
public static class UploadHelper
{
public static MvcHtmlString UploadFile(this HtmlHelper helper, string name, object htmlAttributes = null)
{
TagBuilder input = new TagBuilder("input");
input.Attributes.Add("type", "file");
input.Attributes.Add("id", helper.ViewData.TemplateInfo.GetFullHtmlFieldId(name));
input.Attributes.Add("name", helper.ViewData.TemplateInfo.GetFullHtmlFieldName(name));
if (htmlAttributes != null)
{
var attributes = HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
input.MergeAttributes(attributes);
}
return new MvcHtmlString(input.ToString());
}
}
最后在行动中上传你的文件
[AjaxOnly]
[HttpPost]
public ActionResult UploadImageAction(HttpPostedFileBase UploadImage)
{
string path = Server.MapPath("~") + "Files\\UploadImages\\" + UploadImage.FileName;
System.Drawing.Image img = new Bitmap(UploadImage.InputStream);
img.Save(path);
return View();
}
下面是我的工作示例：
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Create(Product product, HttpPostedFileBase file)
{
if (!ModelState.IsValid)
return PartialView("Create", product);
if (file != null)
{
var fileName = Path.GetFileName(file.FileName);
var guid = Guid.NewGuid().ToString();
var path = Path.Combine(Server.MapPath("~/Content/Uploads/ProductImages"), guid + fileName);
file.SaveAs(path);
string fl = path.Substring(path.LastIndexOf("\\"));
string[] split = fl.Split('\\');
string newpath = split[1];
string imagepath = "Content/Uploads/ProductImages/" + newpath;
using (MemoryStream ms = new MemoryStream())
{
file.InputStream.CopyTo(ms);
byte[] array = ms.GetBuffer();
}
var nId = Guid.NewGuid().ToString();
// Save record to database
product.Id = nId;
product.State = 1;
product.ImagePath = imagepath;
product.CreatedAt = DateTime.Now;
db.Products.Add(product);
await db.SaveChangesAsync();
TempData["message"] = "ProductCreated";
//return RedirectToAction("Index", product);
}
// after successfully uploading redirect the user
return Json(new { success = true });
}
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