(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
尽管我在donnetfiddle上为你做了一个示例项目,但大多数答案似乎都足够合理
我正在使用LumenWorks.Framework进行CSV工作,但这不是必须的。
Demo
View
@using (Html.BeginForm("Index", "Home", "POST"))
{
<div class="form-group">
<label for="file">Upload Files:</label>
<input type="file" multiple name="files" id="files" class="form-control"/><br><br>
<input type="submit" value="Upload Files" class="form-control"/>
</div>
控制器:
[HttpPost]
public ActionResult Index(HttpPostedFileBase upload)
{
if (ModelState.IsValid)
{
if (upload != null && upload.ContentLength > 0)
{
// Validation content length
if (upload.FileName.EndsWith(".csv") || upload.FileName.EndsWith(".CSV"))
{
//extention validation
ViewBag.Result = "Correct File Uploaded";
}
}
}
return View();
}
其他回答
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;
在视图中:
<form action="Categories/Upload" enctype="multipart/form-data" method="post">
<input type="file" name="Image">
<input type="submit" value="Save">
</form>
而控制器中的以下代码:
public ActionResult Upload()
{
foreach (string file in Request.Files)
{
var hpf = this.Request.Files[file];
if (hpf.ContentLength == 0)
{
continue;
}
string savedFileName = Path.Combine(
AppDomain.CurrentDomain.BaseDirectory, "PutYourUploadDirectoryHere");
savedFileName = Path.Combine(savedFileName, Path.GetFileName(hpf.FileName));
hpf.SaveAs(savedFileName);
}
...
}
通常,您还希望传递一个视图模型,而不仅仅是一个文件。在下面的代码中,您将发现一些其他有用的功能:
检查文件是否已附加检查文件大小是否为0检查文件大小是否大于4 MB检查文件大小是否小于100字节检查文件扩展名
可以通过以下代码完成:
[HttpPost]
public ActionResult Index(MyViewModel viewModel)
{
// if file's content length is zero or no files submitted
if (Request.Files.Count != 1 || Request.Files[0].ContentLength == 0)
{
ModelState.AddModelError("uploadError", "File's length is zero, or no files found");
return View(viewModel);
}
// check the file size (max 4 Mb)
if (Request.Files[0].ContentLength > 1024 * 1024 * 4)
{
ModelState.AddModelError("uploadError", "File size can't exceed 4 MB");
return View(viewModel);
}
// check the file size (min 100 bytes)
if (Request.Files[0].ContentLength < 100)
{
ModelState.AddModelError("uploadError", "File size is too small");
return View(viewModel);
}
// check file extension
string extension = Path.GetExtension(Request.Files[0].FileName).ToLower();
if (extension != ".pdf" && extension != ".doc" && extension != ".docx" && extension != ".rtf" && extension != ".txt")
{
ModelState.AddModelError("uploadError", "Supported file extensions: pdf, doc, docx, rtf, txt");
return View(viewModel);
}
// extract only the filename
var fileName = Path.GetFileName(Request.Files[0].FileName);
// store the file inside ~/App_Data/uploads folder
var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
try
{
if (System.IO.File.Exists(path))
System.IO.File.Delete(path);
Request.Files[0].SaveAs(path);
}
catch (Exception)
{
ModelState.AddModelError("uploadError", "Can't save file to disk");
}
if(ModelState.IsValid)
{
// put your logic here
return View("Success");
}
return View(viewModel);
}
确保你有
@Html.ValidationMessage("uploadError")
在您的视图中查看验证错误。
还要记住,默认最大请求长度为4MB(maxRequestLength=4096),要上载更大的文件,必须在web.config中更改此参数:
<system.web>
<httpRuntime maxRequestLength="40960" executionTimeout="1100" />
(此处40960=40 MB)。
执行超时是秒的整数。您可能希望将其更改为允许上传大量文件。
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");
}
我给你简单易懂的方法。
首先,必须在.Cshtml文件中编写以下代码。
<input name="Image" type="file" class="form-control" id="resume" />
然后在控制器中输入以下代码:
if (i > 0) {
HttpPostedFileBase file = Request.Files["Image"];
if (file != null && file.ContentLength > 0) {
if (!string.IsNullOrEmpty(file.FileName)) {
string extension = Path.GetExtension(file.FileName);
switch ((extension.ToLower())) {
case ".doc":
break;
case ".docx":
break;
case ".pdf":
break;
default:
ViewBag.result = "Please attach file with extension .doc , .docx , .pdf";
return View();
}
if (!Directory.Exists(Server.MapPath("~") + "\\Resume\\")) {
System.IO.Directory.CreateDirectory(Server.MapPath("~") + "\\Resume\\");
}
string documentpath = Server.MapPath("~") + "\\Resume\\" + i + "_" + file.FileName;
file.SaveAs(documentpath);
string filename = i + "_" + file.FileName;
result = _objbalResume.UpdateResume(filename, i);
Attachment at = new Attachment(documentpath);
//ViewBag.result = (ans == true ? "Thanks for contacting us.We will reply as soon as possible" : "There is some problem. Please try again later.");
}
} else {
...
}
}
为此,您必须根据您的数据库制作BAL和DAL层。