读取图像，将其转换为byte[]，然后返回具有内容类型的File()。

public ActionResult ImageResult(Image image, ImageFormat format, string contentType) {
  using (var stream = new MemoryStream())
    {
      image.Save(stream, format);
      return File(stream.ToArray(), contentType);
    }
  }
}

以下是用法:

using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using Microsoft.AspNetCore.Mvc;

我也遇到过类似的要求，

所以在我的例子中，我用图像文件夹路径向Controller发出请求，它返回一个ImageResult对象。

下面的代码片段说明了这项工作:

var src = string.Format("/GenericGrid.mvc/DocumentPreviewImageLink?fullpath={0}&routingId={1}&siteCode={2}", fullFilePath, metaInfo.RoutingId, da.SiteCode);

                if (enlarged)
                    result = "<a class='thumbnail' href='#thumb'>" +
                        "<img src='" + src + "' height='66px' border='0' />" +
                        "<span><img src='" + src + "' /></span>" +
                        "</a>";
                else
                    result = "<span><img src='" + src + "' height='150px' border='0' /></span>";

在控制器中，我从图像路径中生成图像并将它返回给调用者

try
{
  var file = new FileInfo(fullpath);
  if (!file.Exists)
     return string.Empty;


  var image = new WebImage(fullpath);
  return new ImageResult(new MemoryStream(image.GetBytes()), "image/jpg");


}
catch(Exception ex)
{
  return "File Error : "+ex.ToString();
}

这对我很管用。 因为我将图像存储在SQL Server数据库上。

    [HttpGet("/image/{uuid}")]
    public IActionResult GetImageFile(string uuid) {
        ActionResult actionResult = new NotFoundResult();
        var fileImage = _db.ImageFiles.Find(uuid);
        if (fileImage != null) {
            actionResult = new FileContentResult(fileImage.Data,
                fileImage.ContentType);
        }
        return actionResult;
    }

在上面的代码片段中，_db.ImageFiles.Find(uuid)正在db (EF上下文)中搜索图像文件记录。它返回一个FileImage对象，它只是一个我为模型制作的自定义类，然后将其用作FileContentResult。

public class FileImage {
   public string Uuid { get; set; }
   public byte[] Data { get; set; }
   public string ContentType { get; set; }
}

如果你想在返回之前修改图像，这可能会有帮助:

public ActionResult GetModifiedImage()
{
    Image image = Image.FromFile(Path.Combine(Server.MapPath("/Content/images"), "image.png"));

    using (Graphics g = Graphics.FromImage(image))
    {
        // do something with the Graphics (eg. write "Hello World!")
        string text = "Hello World!";

        // Create font and brush.
        Font drawFont = new Font("Arial", 10);
        SolidBrush drawBrush = new SolidBrush(Color.Black);

        // Create point for upper-left corner of drawing.
        PointF stringPoint = new PointF(0, 0);

        g.DrawString(text, drawFont, drawBrush, stringPoint);
    }

    MemoryStream ms = new MemoryStream();

    image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);

    return File(ms.ToArray(), "image/png");
}

解决方案1:从图像URL在视图中呈现图像

你可以创建自己的扩展方法:

public static MvcHtmlString Image(this HtmlHelper helper,string imageUrl)
{
   string tag = "<img src='{0}'/>";
   tag = string.Format(tag,imageUrl);
   return MvcHtmlString.Create(tag);
}

然后这样使用它:

@Html.Image(@Model.ImagePath);

解决方案2:从数据库中渲染图像

创建一个返回图像数据的控制器方法，如下所示

public sealed class ImageController : Controller
{
  public ActionResult View(string id)
  {
    var image = _images.LoadImage(id); //Pull image from the database.
    if (image == null) 
      return HttpNotFound();
    return File(image.Data, image.Mime);
  }
}

并在视图中使用它:

@ { Html.RenderAction("View","Image",new {id=@Model.ImageId})}

要在任何HTML中使用此actionresult渲染的图像，请使用

<img src="http://something.com/image/view?id={imageid}>

你可以使用文件返回一个文件，如视图，内容等

 public ActionResult PrintDocInfo(string Attachment)
            {
                string test = Attachment;
                if (test != string.Empty || test != "" || test != null)
                {
                    string filename = Attachment.Split('\\').Last();
                    string filepath = Attachment;
                    byte[] filedata = System.IO.File.ReadAllBytes(Attachment);
                    string contentType = MimeMapping.GetMimeMapping(Attachment);

                    System.Net.Mime.ContentDisposition cd = new System.Net.Mime.ContentDisposition
                    {
                        FileName = filename,
                        Inline = true,
                    };

                    Response.AppendHeader("Content-Disposition", cd.ToString());

                    return File(filedata, contentType);          
                }
                else { return Content("<h3> Patient Clinical Document Not Uploaded</h3>"); }

            }