asp.net mvc 从数据库中读取图片

今天搞了一天的MVC，在显示图片的时候老是出现问题，从网上搜索了好久，才找到解决方法。

首先是创建一个类，继承于ActionResult，记住要引用System.Web.Mvc命名空间，如下：

public class ImageResult : ActionResult
    {
        public ImageFormat ContentType { get; set; }
        public Image image { get; set; }
        public string SourceName { get; set; }

        public ImageResult(string _SourceName, ImageFormat _ContentType)
        {
            this.SourceName = _SourceName;
            this.ContentType = _ContentType;
        }

        public ImageResult(Image _ImageBytes, ImageFormat _ContentType)
        {
            this.ContentType = _ContentType;
            this.image = _ImageBytes;
        }

        public override void ExecuteResult(ControllerContext context)
        {
            context.HttpContext.Response.Clear();
            context.HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
            if (ContentType.Equals(ImageFormat.Bmp)) context.HttpContext.Response.ContentType = "image/bmp";
            if (ContentType.Equals(ImageFormat.Gif)) context.HttpContext.Response.ContentType = "image/gif";
            if (ContentType.Equals(ImageFormat.Icon)) context.HttpContext.Response.ContentType = "image/vnd.microsoft.icon";
            if (ContentType.Equals(ImageFormat.Jpeg)) context.HttpContext.Response.ContentType = "image/jpeg";
            if (ContentType.Equals(ImageFormat.Png)) context.HttpContext.Response.ContentType = "image/png";
            if (ContentType.Equals(ImageFormat.Tiff)) context.HttpContext.Response.ContentType = "image/tiff";
            if (ContentType.Equals(ImageFormat.Wmf)) context.HttpContext.Response.ContentType = "image/wmf";
            if (image != null)
            {
                image.Save(context.HttpContext.Response.OutputStream, ContentType);
            }
            else
            {
                context.HttpContext.Response.TransmitFile(SourceName);
            }
        }
    }

然后在 Controller类中创建一个Action.如下：

public ActionResult GetPicture(int id)
        {         
            ICategory server = new CategoryServer();
            byte[] buffer = server.getCategoryPicture(id);
            if (buffer != null)
            {
                MemoryStream stream = new MemoryStream(buffer);
                System.Drawing.Image image = System.Drawing.Image.FromStream(stream);
                ImageResult result = new ImageResult(image, System.Drawing.Imaging.ImageFormat.Jpeg);
                return result;
            }
            return View();
        } 

这样就可以显示图片了。

下面几种方法可以显示已经存在的图片 

方法一：

using System.IO;

public FileResult Image() {
    string path = Server.MapPath("/Content/Images/Decorative/");
    string filename = Request.Url.Segments[Request.Url.Segments.Length - 1].ToString();

    // Uss Path.Combine from System.IO instead of StringBuilder.
    string fullPath = Path.Combine(path, filename);

    return(new FileResult(fullPath, "image/jpeg"));

}
方法二:
public ActionResult Image(string id)
{
    var dir = Server.MapPath("/Images");
    var path = Path.Combine(dir, id + ".jpg");
    return base.File(path, "image/jpg");
}
方法三：
[AcceptVerbs(HttpVerbs.Get)]
[OutputCache(CacheProfile = "CustomerImages")]
public FileResult Show(int customerId, string imageName)
{
    var path = string.Concat(ConfigData.ImagesDirectory, customerId, @"\", imageName);
    return new FileStreamResult(new FileStream(path, FileMode.Open), "image/jpeg");
}
这三种都可以显示已经存在的图片
并且我认为第三种方法可以修改为从数据库中读取图片显示。