(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?
(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
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。
Html:
@using (Html.BeginForm("StoreMyCompany", "MyCompany", FormMethod.Post, new { id = "formMyCompany", enctype = "multipart/form-data" }))
{
<div class="form-group">
@Html.LabelFor(model => model.modelMyCompany.Logo, htmlAttributes: new { @class = "control-label col-md-3" })
<div class="col-md-6">
<input type="file" name="Logo" id="fileUpload" accept=".png,.jpg,.jpeg,.gif,.tif" />
</div>
</div>
<br />
<div class="form-group">
<div class="col-md-offset-3 col-md-6">
<input type="submit" value="Save" class="btn btn-success" />
</div>
</div>
}
背后代码:
public ActionResult StoreMyCompany([Bind(Exclude = "Logo")]MyCompanyVM model)
{
try
{
byte[] imageData = null;
if (Request.Files.Count > 0)
{
HttpPostedFileBase objFiles = Request.Files["Logo"];
using (var binaryReader = new BinaryReader(objFiles.InputStream))
{
imageData = binaryReader.ReadBytes(objFiles.ContentLength);
}
}
if (imageData != null && imageData.Length > 0)
{
//Your code
}
dbo.SaveChanges();
return RedirectToAction("MyCompany", "Home");
}
catch (Exception ex)
{
Utility.LogError(ex);
}
return View();
}
您不使用文件输入控件。ASP.NET MVC中未使用服务器端控件。查看下面的博客文章,其中说明了如何在ASP.NET MVC中实现这一点。
因此,您将首先创建一个HTML表单,其中包含文件输入:
@using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" name="file" />
<input type="submit" value="OK" />
}
然后你会有一个控制器来处理上传:
public class HomeController : Controller
{
// This action renders the form
public ActionResult Index()
{
return View();
}
// This action handles the form POST and the upload
[HttpPost]
public ActionResult Index(HttpPostedFileBase file)
{
// Verify that the user selected a file
if (file != null && file.ContentLength > 0)
{
// extract only the filename
var fileName = Path.GetFileName(file.FileName);
// store the file inside ~/App_Data/uploads folder
var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
file.SaveAs(path);
}
// redirect back to the index action to show the form once again
return RedirectToAction("Index");
}
}
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();
}