ASP Net MVC How to display a byte array image from model

Question

I ve a model with a byte array image file that I want to show on the page   How can I do that without going back to the Database   All the solutions that I see use an ActionResult to go back to the database to retrieve the image  but I already have the image on the model

User · Answer

I recommend something along these lines  even if the image lives inside of your model    I realize you are asking for a direct way to access it right from the view and many others have answered that and told you what is wrong with that approach so this is just another way that will load the image in an async fashion for you and I think is a better approach   Sample Model    Bind Exclude    ID    public class Item        Key       ScaffoldColumn false       public int ID   get  set         public String Name   get  set         public byte   InternalImage   get  set      Stored as byte array in the database      Sample Method in the Controller   public async Task lt ActionResult gt  RenderImage int id        Item item   await db Items FindAsync id        byte   photoBack   item InternalImage       return File photoBack   image png        View   model YourNameSpace Models Item         ViewBag Title    Details       lt h2 gt Details lt  h2 gt    lt div gt   lt h4 gt Item lt  h4 gt   lt hr   gt   lt dl class  dl-horizontal  gt       lt img src   Url Action  RenderImage   new   id   Model ID      gt   lt  dl gt   lt dl class  dl-horizontal  gt       lt dt gt           Html DisplayNameFor model   gt  model Name       lt  dt gt        lt dd gt           Html DisplayFor model   gt  model Name       lt  dd gt   lt  dl gt   lt  div gt

User · Answer

I ve created a helper method based in the asnwer below and I m pretty glad that this helper can help as many as possible   With a model    public class Images         Key      public int ImagesId   get  set         DisplayName  Image        public Byte   Pic1   get  set          The helper is   public static IHtmlString GetBytes lt TModel  TValue gt  this HtmlHelper lt TModel gt  helper  System Linq Expressions Expression lt Func lt TModel  TValue gt  gt  expression  byte   array  string Id                TagBuilder tb   new TagBuilder  img            tb MergeAttribute  id   Id           var base64   Convert ToBase64String array           var imgSrc   String Format  data image gif base64  0    base64           tb MergeAttribute  src   imgSrc           return MvcHtmlString Create tb ToString TagRenderMode SelfClosing            The view is receiving a  ICollection object so you need to used it in the view in a foreach statement     foreach  var item in Model     Html GetBytes itemP1   gt  item Pic1  item Graphics   Idtag

User · Answer

This worked for me   lt img src  data image base64  System Convert ToBase64String Model CategoryPicture Content   width  80  height  80   gt

User · Answer

If you can base-64 encode your bytes  you could try using the result as your image source  In your model you might add something like   public string ImageSource       get               string mimeType      Get mime type somehow  e g   image png               string base64   Convert ToBase64String yourImageBytes           return string Format  data  0  base64  1    mimeType  base64             And in your view    lt img     src   Model ImageSource    gt

User · Answer

Something like this may work            var base64   Convert ToBase64String Model ByteArray       var imgSrc   String Format  data image gif base64  0    base64       lt img src   imgSrc    gt    As mentioned in the comments below  please use the above armed with the knowledge that although this may answer your question it may not solve your problem  Depending on your problem this may be the solution but I wouldn t completely rule out accessing the database twice

User · Answer

If the image isn t that big  and if there s a good chance you ll be re-using the image often  and if you don t have too many of them  and if the images are not secret  meaning it s no big deal if one user could potentially see another person s image      Lots of  if s here  so there s a good chance this is a bad idea   You can store the image bytes in Cache for a short time  and make an image tag pointed toward an action method  which in turn reads from the cache and spits out your image  This will allow the browser to cache the image appropriately      In your original controller action HttpContext Cache Add  image-    model Id  model ImageBytes  null      Cache NoAbsoluteExpiration  TimeSpan FromMinutes 1       CacheItemPriority Normal  null       In your view   lt img src   Url Action  GetImage    MyControllerName   new fooId   Model Id    gt      In your controller   OutputCache VaryByParam    fooId   Duration   60   public ActionResult GetImage int fooId           Make sure you check for null as appropriate  re-pull from DB  etc      return File  byte   HttpContext Cache  image-    fooId    image gif        This has the added benefit  or is it a crutch   of working in older browsers  where the inline images don t work in IE7  or IE8 if larger than 32kB

User · Answer

You need to have a byte   in your DB   My byte   is in my Person object   public class Person       public byte   Image   get  set         You need to convert your byte   in a String  So  I have in my controller    String img   Convert ToBase64String person Image       Next  in my  cshtml file  my Model is a ViewModel  This is what I have in     public String Image   get  set       I use it like this in my  cshtml file     lt img src   String Format  data image jpg base64  0    Model Image     gt     data image image file extension base64  0   your image String    I wish it will help someone

User · Answer

One way is to add this to a new c  class or HtmlExtensions class  public static class HtmlExtensions       public static MvcHtmlString Image this HtmlHelper html  byte   image                var img   String Format  data image jpg base64  0    Convert ToBase64String image            return new MvcHtmlString   lt img src      img        gt               then you can do this in any view    Html Image Model ImgBytes

User · Answer

This is an modified version of Manoj s answer that I use on a project  Just updated to take a class  html attributes and use the TagBuilder       public static IHtmlString Image this HtmlHelper helper  byte   image  string imgclass                                        object htmlAttributes   null                var builder   new TagBuilder  img            builder MergeAttribute  class   imgclass           builder MergeAttributes new RouteValueDictionary htmlAttributes             var imageString   image    null   Convert ToBase64String image                var img   string Format  data image jpg base64  0    imageString           builder MergeAttribute  src   img            return MvcHtmlString Create builder ToString TagRenderMode SelfClosing            Which can be used then as follows        Html Image Model Image   img-cls   new   width  200   height  200

User · Answer

If you want to present the image  add a method as a helper class or to the model itself and allow the method to convert the byte array image to a image format like PNG or JPG then convert to Base64 string   Once you have that  bind the base64 value on your view in the format    data image  image file type extension  base64  your base64 string goes here    The above is assigned to the img tag s src attribute   The only issue I have with this is the base64 string being too long   So  I would not recommend it for multiple models being shown in a view

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