(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
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();
}
其他回答
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();
}
如果有人想用Ajax上传多个文件,下面是我的文章在Asp.NetMVC中使用Ajax进行多文件上传
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;
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");
}
}
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。