(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
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);
}
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);
}
...
}
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();
}
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" />
}
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);
}