（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
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" />
}
其他回答
提供完整的解决方案
首先在MVC视图中使用.CShtml中的输入
<input type="file" id="UploadImg" /></br>
<img id="imgPreview" height="200" width="200" />
现在调用Ajax调用
$("#UploadImg").change(function () {
var data = new FormData();
var files = $("#UploadImg").get(0).files;
if (files.length > 0) {
data.append("MyImages", files[0]);
}
$.ajax({
// url: "Controller/ActionMethod"
url: "/SignUp/UploadFile",
type: "POST",
processData: false,
contentType: false,
data: data,
success: function (response)
{
//code after success
$("#UploadPhoto").val(response);
$("#imgPreview").attr('src', '/Upload/' + response);
},
error: function (er) {
//alert(er);
}
});
});
控制器Json呼叫
[HttpGet]
public JsonResult UploadFile()
{
string _imgname = string.Empty;
if (System.Web.HttpContext.Current.Request.Files.AllKeys.Any())
{
var pic = System.Web.HttpContext.Current.Request.Files["MyImages"];
if (pic.ContentLength > 0)
{
var fileName = Path.GetFileName(pic.FileName);
var _ext = Path.GetExtension(pic.FileName);
_imgname = Guid.NewGuid().ToString();
var _comPath = Server.MapPath("/MyFolder") + _imgname + _ext;
_imgname = "img_" + _imgname + _ext;
ViewBag.Msg = _comPath;
var path = _comPath;
tblAssignment assign = new tblAssignment();
assign.Uploaded_Path = "/MyFolder" + _imgname + _ext;
// Saving Image in Original Mode
pic.SaveAs(path);
}
}
return Json(Convert.ToString(_imgname), JsonRequestBehavior.AllowGet);
}
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");
}
我在做文件上传概念时也遇到过同样的错误。我知道开发人员为这个问题提供了很多答案。
尽管我回答这个问题的原因是，由于下面提到的疏忽错误，我犯了这个错误。
<input type="file" name="uploadedFile" />
在指定name属性时，请确保控制器参数也具有相同的名称值“uploadedFile”。这样地：
[HttpPost]
public ActionResult FileUpload(HttpPostedFileBase uploadedFile)
{
}
否则它不会被映射。
保存多个文件的简单方法
cshtml
@using (Html.BeginForm("Index","Home",FormMethod.Post,new { enctype = "multipart/form-data" }))
{
<label for="file">Upload Files:</label>
<input type="file" multiple name="files" id="files" /><br><br>
<input type="submit" value="Upload Files" />
<br><br>
@ViewBag.Message
}
控制器
[HttpPost]
public ActionResult Index(HttpPostedFileBase[] files)
{
foreach (HttpPostedFileBase file in files)
{
if (file != null && file.ContentLength > 0)
try
{
string path = Path.Combine(Server.MapPath("~/Files"), Path.GetFileName(file.FileName));
file.SaveAs(path);
ViewBag.Message = "File uploaded successfully";
}
catch (Exception ex)
{
ViewBag.Message = "ERROR:" + ex.Message.ToString();
}
else
{
ViewBag.Message = "You have not specified a file.";
}
}
return View();
}
推荐文章
- 返回文件在ASP。Net Core Web API
- 自定义HttpClient请求头
- 如果我使用OWIN Startup.cs类并将所有配置移动到那里，我是否需要一个Global.asax.cs文件?
- ASP。NET Identity DbContext混淆
- VS2013外部构建错误"error MSB4019: The imported project <path> was not found"
- 从另一个列表id中排序一个列表
- 等待一个无效的异步方法
- 无法加载文件或程序集…参数不正确
- c#中枚举中的方法
- 如何从字符串中删除新的行字符?
- 如何设置一个默认值与Html.TextBoxFor?
- 检查属性是否有属性
- 格式化XML字符串以打印友好的XML字符串
- 返回内容与IHttpActionResult非ok响应
- web页面的功能是什么:在MVC 3 web.config中启用
