(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

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" />
}

我必须上传100kb的文件块,最后一个上传文件使用命令存储在数据库中。我希望,这会对你有所帮助。

    public HttpResponseMessage Post(AttachmentUploadForm form)
    {
        var response = new WebApiResultResponse
        {
            IsSuccess = true,
            RedirectRequired = false
        };

        var tempFilesFolder = Sanelib.Common.SystemSettings.Globals.CreateOrGetCustomPath("Temp\\" + form.FileId);

        File.WriteAllText(tempFilesFolder + "\\" + form.ChunkNumber + ".temp", form.ChunkData);

        if (form.ChunkNumber < Math.Ceiling((double)form.Size / 102400)) return Content(response);

        var folderInfo = new DirectoryInfo(tempFilesFolder);
        var totalFiles = folderInfo.GetFiles().Length;

        var sb = new StringBuilder();

        for (var i = 1; i <= totalFiles; i++)
        {
            sb.Append(File.ReadAllText(tempFilesFolder + "\\" + i + ".temp"));
        }

        var base64 = sb.ToString();
        base64 = base64.Substring(base64.IndexOf(',') + 1);
        var fileBytes = Convert.FromBase64String(base64);
        var fileStream = new FileStream(tempFilesFolder + "\\" + form.Name, FileMode.OpenOrCreate, FileAccess.ReadWrite);
        fileStream.Seek(fileStream.Length, SeekOrigin.Begin);
        fileStream.Write(fileBytes, 0, fileBytes.Length);
        fileStream.Close();

        Directory.Delete(tempFilesFolder, true);

        var md5 = MD5.Create();

        var command = Mapper.Map<AttachmentUploadForm, AddAttachment>(form);
        command.FileData = fileBytes;
        command.FileHashCode = BitConverter.ToString(md5.ComputeHash(fileBytes)).Replace("-", "");

        return ExecuteCommand(command);
    }

Javascript(Knockout Js)

define(['util', 'ajax'], function (util, ajax) {
"use strict";

var exports = {},
     ViewModel, Attachment, FileObject;

//File Upload
FileObject = function (file, parent) {
    var self = this;
    self.fileId = util.guid();
    self.name = ko.observable(file.name);
    self.type = ko.observable(file.type);
    self.size = ko.observable();
    self.fileData = null;
    self.fileSize = ko.observable(file.size / 1024 / 1024);
    self.chunks = 0;
    self.currentChunk = ko.observable();

    var reader = new FileReader();

    // Closure to capture the file information.
    reader.onload = (function (e) {
        self.fileData = e.target.result;
        self.size(self.fileData.length);
        self.chunks = Math.ceil(self.size() / 102400);
        self.sendChunk(1);
    });

    reader.readAsDataURL(file);

    self.percentComplete = ko.computed(function () {
        return self.currentChunk() * 100 / self.chunks;
    }, self);

    self.cancel = function (record) {
        parent.uploads.remove(record);
    };

    self.sendChunk = function (number) {
        var start = (number - 1) * 102400;
        var end = number * 102400;
        self.currentChunk(number);
        var form = {
            fileId: self.fileId,
            name: self.name(),
            fileType: self.type(),
            Size: self.size(),
            FileSize: self.fileSize(),
            chunkNumber: number,
            chunkData: self.fileData.slice(start, end),
            entityTypeValue: parent.entityTypeValue,
            ReferenceId: parent.detail.id,
            ReferenceName: parent.detail.name
        };

        ajax.post('Attachment', JSON.stringify(form)).done(function (response) {
            if (number < self.chunks)
                self.sendChunk(number + 1);
            if (response.id != null) {
                parent.attachments.push(new Attachment(response));
                self.cancel(response);
            }
        });
    };
};

Attachment = function (data) {
    var self = this;
    self.id = ko.observable(data.id);
    self.name = ko.observable(data.name);
    self.fileType = ko.observable(data.fileType);
    self.fileSize = ko.observable(data.fileSize);
    self.fileData = ko.observable(data.fileData);
    self.typeName = ko.observable(data.typeName);
    self.description = ko.observable(data.description).revertable();
    self.tags = ko.observable(data.tags).revertable();
    self.operationTime = ko.observable(moment(data.createdOn).format('MM-DD-YYYY HH:mm:ss'));

    self.description.subscribe(function () {
        var form = {
            Id: self.id(),
            Description: self.description(),
            Tags: self.tags()
        };

        ajax.put('attachment', JSON.stringify(form)).done(function (response) {
            self.description.commit();
            return;
        }).fail(function () {
            self.description.revert();
        });
    });

    self.tags.subscribe(function () {
        var form = {
            Id: self.id(),
            Description: self.description(),
            Tags: self.tags()
        };

        ajax.put('attachment', JSON.stringify(form)).done(function (response) {
            self.tags.commit();
            return;
        }).fail(function () {
            self.tags.revert();
        });
    });
};

ViewModel = function (data) {
    var self = this;

    // for attachment
    self.attachments = ko.observableArray([]);
    $.each(data.attachments, function (row, val) {
        self.attachments.push(new Attachment(val));
    });

    self.deleteAttachmentRecord = function (record) {
        if (!confirm("Are you sure you want to delete this record?")) return;
        ajax.del('attachment', record.id(), { async: false }).done(function () {
            self.attachments.remove(record);
            return;
        });
    };


exports.exec = function (model) {
    console.log(model);
    var viewModel = new ViewModel(model);
    ko.applyBindings(viewModel, document.getElementById('ShowAuditDiv'));
};

return exports;
});

HTML代码:

<div class="row-fluid spacer-bottom fileDragHolder">
    <div class="spacer-bottom"></div>
    <div class="legend">
        Attachments<div class="pull-right">@Html.AttachmentPicker("AC")</div>
    </div>
    <div>
        <div class="row-fluid spacer-bottom">
            <div style="overflow: auto">
                <table class="table table-bordered table-hover table-condensed" data-bind="visible: uploads().length > 0 || attachments().length > 0">
                    <thead>
                        <tr>
                            <th class=" btn btn-primary col-md-2" style="text-align: center">
                                Name
                            </th>
                            <th class="btn btn-primary col-md-1" style="text-align: center">Type</th>
                            <th class="btn btn-primary col-md-1" style="text-align: center">Size (MB)</th>
                            <th class="btn btn-primary col-md-1" style="text-align: center">Upload Time</th>
                            <th class="btn btn-primary col-md-1" style="text-align: center">Tags</th>
                            <th class="btn btn-primary col-md-6" style="text-align: center">Description</th>
                            <th class="btn btn-primary col-md-1" style="text-align: center">Delete</th>
                        </tr>
                    </thead>
                    <tbody>
                        <!-- ko foreach: attachments -->
                        <tr>
                            <td style="text-align: center" class="col-xs-2"><a href="#" data-bind="text: name,attr:{'href':'/attachment/index?id=' + id()}"></a></td>
                            <td style="text-align: center" class="col-xs-1"><span data-bind="text: fileType"></span></td>
                            <td style="text-align: center" class="col-xs-1"><span data-bind="text: fileSize"></span></td>
                            <td style="text-align: center" class="col-xs-2"><span data-bind="text: operationTime"></span></td>
                            <td style="text-align: center" class="col-xs-3"><div contenteditable="true" data-bind="editableText: tags"></div></td>
                            <td style="text-align: center" class="col-xs-4"><div contenteditable="true" data-bind="editableText: description"></div></td>
                            <td style="text-align: center" class="col-xs-1"><button class="btn btn-primary" data-bind="click:$root.deleteAttachmentRecord"><i class="icon-trash"></i></button></td>
                        </tr>
                        <!-- /ko -->
                    </tbody>
                    <tfoot data-bind="visible: uploads().length > 0">
                        <tr>
                            <th colspan="6">Files upload status</th>
                        </tr>
                        <tr>
                            <th>Name</th>
                            <th>Type</th>
                            <th>Size (MB)</th>
                            <th colspan="2">Status</th>
                            <th></th>
                        </tr>
                        <!-- ko foreach: uploads -->
                        <tr>
                            <td><span data-bind="text: name"></span></td>
                            <td><span data-bind="text: type"></span></td>
                            <td><span data-bind="text: fileSize"></span></td>
                            <td colspan="2">
                                <div class="progress">
                                    <div class="progress-bar" data-bind="style: { width: percentComplete() + '%' }"></div>
                                </div>
                            </td>
                            <td style="text-align: center"><button class="btn btn-primary" data-bind="click:cancel"><i class="icon-trash"></i></button></td>
                        </tr>
                        <!-- /ko -->
                    </tfoot>
                </table>
            </div>
            <div data-bind="visible: attachments().length == 0" class="span12" style="margin-left:0">
                <span>No Records found.</span>
            </div>
        </div>

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。

下面是我的工作示例:

[HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> Create(Product product, HttpPostedFileBase file)
    {
        if (!ModelState.IsValid)
            return PartialView("Create", product);
        if (file != null)
        {

            var fileName = Path.GetFileName(file.FileName);
            var guid = Guid.NewGuid().ToString();
            var path = Path.Combine(Server.MapPath("~/Content/Uploads/ProductImages"), guid + fileName);
            file.SaveAs(path);
            string fl = path.Substring(path.LastIndexOf("\\"));
            string[] split = fl.Split('\\');
            string newpath = split[1];
            string imagepath = "Content/Uploads/ProductImages/" + newpath;
            using (MemoryStream ms = new MemoryStream())
            {
                file.InputStream.CopyTo(ms);
                byte[] array = ms.GetBuffer();
            }
            var nId = Guid.NewGuid().ToString();
            // Save record to database
            product.Id = nId;
            product.State = 1;
            product.ImagePath = imagepath;
            product.CreatedAt = DateTime.Now;
            db.Products.Add(product);
            await db.SaveChangesAsync();
            TempData["message"] = "ProductCreated";

            //return RedirectToAction("Index", product);
        }
        // after successfully uploading redirect the user
        return Json(new { success = true });
    }

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;