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" />
}

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();
        }

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" />
}

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。

在控制器中

 if (MyModal.ImageFile != null)
                    {
                        MyModal.ImageURL = string.Format("{0}.{1}", Guid.NewGuid().ToString(), MyModal.ImageFile.FileName.Split('.').LastOrDefault());
                        if (MyModal.ImageFile != null)
                        {
                            var path = Path.Combine(Server.MapPath("~/Content/uploads/"), MyModal.ImageURL);
                            MyModal.ImageFile.SaveAs(path);
                        }
                    }

在视图中

<input type="hidden" value="" name="..."><input id="ImageFile" type="file" name="ImageFile" src="@Model.ImageURL">

在模态类中

 public HttpPostedFileBase ImageFile { get; set; }

在项目的Content文件夹中创建上载文件夹