I want to access and return a resource image from a DLL /connected project.
(Its a file, with build action of Resource). It is not listed in properties/resource as there are hundreds of them in the folder.
The idea is that I can call an image controller.
public ImageResult Display(string resourcePath){
Uri uri = new Uri("pack://application:,,,/ProjectName;component/Images/Vectors/" + resourcePath, UriKind.Absolute);
// What goes here??
}
The problem is i dont know how to turn the URI into an image, in MVC5.
I want to be able to call it from the view. using the url property of the <img> tag
I think you could try WebClient.DownloadData() method to download the image as byte array from specified URI, then convert it to Base64 format with Convert.ToBase64String() and display it on <img> tag using a string property in the viewmodel as src attribute value, below is an example to display the image:
Viewmodel Example
public class ViewModel
{
// other properties
// used to pass image into src attribute of img tag
public string ImageData { get; set; }
}
Controller Action
public ActionResult Display(string resourcePath)
{
Uri uri = new Uri("pack://application:,,,/ProjectName;component/Images/Vectors/" + resourcePath, UriKind.Absolute);
using (var wc = new System.Net.WebClient())
{
// download URI resource as byte array
byte[] image = wc.DownloadData(uri);
// get image extension
string path = string.Format("{0}{1}{2}{3}", uri.Scheme, Uri.SchemeDelimiter, uri.Authority, uri.AbsolutePath);
string extension = System.IO.Path.GetExtension(path).Replace(".", "");
// assign image to viewmodel property as Base64 string format
var model = new ViewModel();
model.ImageData = string.Format("data:image/{0};base64,{1}", extension, Convert.ToBase64String(image));
return View(model);
}
}
View
#model ViewModel
<img src="#Model.ImageData" ... />
Additional note:
If you already know the extension from the resource URI, you could use it directly instead of using Path.GetExtension, here is an example for JPG format:
model.ImageData = string.Format("data:image/jpg;base64,{0}", Convert.ToBase64String(image));
Related issues:
Image to byte array from a url
MVC How to display a byte array image from model
Be sure to register the pack:// scheme as this won't automatically be registered in an MVC app as it is in a WPF app.
In this example code, Blarn0 is a public property in my model class to ensure that the access to the PackUriHelper.UriSchemePack property isn't optimized away when the code is published in Release configuration. I'm sure one can use discards for this very purpose in later versions of C#.
const string scheme = "pack";
if (!UriParser.IsKnownScheme(scheme))
Blarn0 = PackUriHelper.UriSchemePack;
Related
In my controller I have created an action that returns images from a database. The images are stored as bytearrays, so I'm returning the contents as a FileContentResult.
In the view, I'm linking to this action with:
<img src="#Url.Action("GetImage", new { id=a.Id })"/>
The controller action looks like
public ActionResult GetImage(long id)
{
var article = SolrOperations.GetArticleById(id);
if (article != null && !string.IsNullOrEmpty(article.Image) && !string.IsNullOrEmpty(article.ImageType))
{
var imageBytes = Convert.FromBase64String(article.Image);
return new FileContentResult(imageBytes, article.ImageType);
}
return null;
}
This does not yield the desired behavior (even though the images are displayed), as I need the full link to the image, ie: /getimage/id.jpg instead of just /getimage/id. The reason for this is that I want to use ImageProcessor.Web to further process (and cache) the images by supplying a query string in the image src attribute (fx src="myimage.jpg?filter=greyscale").
If you want to axtend the link you can just extend your controller method signature, like this:
public ActionResult GetImage(long id , string src, string filter)
ASP.NET MVC will bind this values and on your View you can write like this:
<img src="#Url.Action("GetImage", new { id=a.Id, src = "myimage.jpg", filter = "greyscale" })"/>
I'm using MVC 3 and using the AjaxUpload plugin to upload an image using AJAX. I don't want to save the image in the file system, instead save it to the session object and then output the stream to populate an image control on the form? Would anyone know how to do this?
No idea why would ever want to do that (store the file in session) because if you have lots of users uploading their files at the same time, storing those files in the memory of your web server, especially if those files are big, won't make this server last very long. Storing the file on the filesystem is the recommended approach.
But anyway, here's how you could do it (assuming you didn't read or cared about my previous remark):
[HttpPost]
public ActionResult Upload(MyViewModel model)
{
if (!ModelState.IsValid)
{
return View(model);
}
var buffer = new byte[model.File.InputStream];
model.File.InputStream.Read(buffer, 0, buffer.Length);
Session["uploadedFile"] = buffer;
return View(model);
}
where the File property on the view models is a HttpPostedFileBase. Next you could have a controller action which will serve this file:
public ActionResult Image()
{
byte[] buffer = (byte[])Session["uploadedFile"];
return File(buffer, "image/png");
}
and in the view you will have an <img> tag pointing to this action:
<img src="#Url.Action("image")" alt="" />
Now of course the AjaxUpload plugin allows you to upload the file using AJAX, so you don't need to reload the entire page. So in this case your controller action could simply return a JSON object to indicate whether the upload process succeeded and then in the success callback set the src property of the <img> tag to the controller action that will serve the file.
SomeView.cshtml:
<img src="#Url.Action("/Image/Render")" />
ImageController.cs:
public ActionResult Render() {
return File((byte[])Session["Avatar"], "image/jpeg")
}
Some example code. Modify it to whatever you want to do. Not really a good idea to sling an image into a session if lots of users. Better to stick it into a db if short lived, or if long lived, a more permanent storage (filesystem maybe).
public ActionResult UploadImage()
{
foreach (string imageName in Request.Files)
{
HttpPostedFileBase file = Request.Files[imageName];
if (file.ContentLength > 0)
{
BinaryReader br = new BinaryReader(file.InputStream);
byte[] content = br.ReadBytes(file.ContentLength);
Session[imageName] = content; // better to store in a db here
}
}
return View();
}
// return the image (controller action) /mycontroller/ViewImage?imageName=whatever
public FileStreamResult ViewImage(string imageName)
{
byte[] content = (byte[])Session[imageName] ; // where ever your content is stored (ideally something other than session)
MemoryStream ms = new MemoryStream(content);
return new FileStreamResult(ms, "application/octet-stream"); // set content type based on input image, it might be png, jpg, gif etc.,
}
Hope this helps.
Is there a way to stream a file using ASP.NET MVC FileContentResult within the browser with a specific name?
I have noticed that you can either have a FileDialog (Open/Save) or you can stream the file in a browser window, but then it will use the ActionName when you try to save the file.
I have the following scenario:
byte[] contents = DocumentServiceInstance.CreateDocument(orderId, EPrintTypes.Quote);
result = File(contents, "application/pdf", String.Format("Quote{0}.pdf", orderId));
When I use this, I can stream the bytes, but a OPEN/SAVE file dialog is given to the user. I would like to actually stream this file in a browser window.
If I just use the FilePathResult, it shows the file in a browser window, but then when I click on "Save" button to save the file in PDF, it shows me the Action Name as the name of the file.
Has anyone encountered this?
public ActionResult Index()
{
byte[] contents = FetchPdfBytes();
return File(contents, "application/pdf", "test.pdf");
}
and for opening the PDF inside the browser you will need to set the Content-Disposition header:
public ActionResult Index()
{
byte[] contents = FetchPdfBytes();
Response.AddHeader("Content-Disposition", "inline; filename=test.pdf");
return File(contents, "application/pdf");
}
Actually, the absolutely easiest way is to do the following...
byte[] content = your_byte[];
FileContentResult result = new FileContentResult(content, "application/octet-stream")
{
FileDownloadName = "your_file_name"
};
return result;
This might be helpful for whoever else faces this problem. I finally figured out a solution. Turns out, even if we use the inline for "content-disposition" and specify a file name, the browsers still do not use the file name. Instead browsers try and interpret the file name based on the Path/URL.
You can read further on this URL:
Securly download file inside browser with correct filename
This gave me an idea, I just created my URL route that would convert the URL and end it with the name of the file I wanted to give the file. So for e.g. my original controller call just consisted of passing the Order Id of the Order being printed. I was expecting the file name to be of the format Order{0}.pdf where {0} is the Order Id. Similarly for quotes, I wanted Quote{0}.pdf.
In my controller, I just went ahead and added an additional parameter to accept the file name. I passed the filename as a parameter in the URL.Action method.
I then created a new route that would map that URL to the format:
http://localhost/ShoppingCart/PrintQuote/1054/Quote1054.pdf
routes.MapRoute("", "{controller}/{action}/{orderId}/{fileName}",
new { controller = "ShoppingCart", action = "PrintQuote" }
, new string[] { "x.x.x.Controllers" }
);
This pretty much solved my issue.
Previous answers are correct: adding the line...
Response.AddHeader("Content-Disposition", "inline; filename=[filename]");
...will causing multiple Content-Disposition headers to be sent down to the browser. This happens b/c FileContentResult internally applies the header if you supply it with a file name. An alternative, and pretty simple, solution is to simply create a subclass of FileContentResult and override its ExecuteResult() method. Here's an example that instantiates an instance of the System.Net.Mime.ContentDisposition class (the same object used in the internal FileContentResult implementation) and passes it into the new class:
public class FileContentResultWithContentDisposition : FileContentResult
{
private const string ContentDispositionHeaderName = "Content-Disposition";
public FileContentResultWithContentDisposition(byte[] fileContents, string contentType, ContentDisposition contentDisposition)
: base(fileContents, contentType)
{
// check for null or invalid ctor arguments
ContentDisposition = contentDisposition;
}
public ContentDisposition ContentDisposition { get; private set; }
public override void ExecuteResult(ControllerContext context)
{
// check for null or invalid method argument
ContentDisposition.FileName = ContentDisposition.FileName ?? FileDownloadName;
var response = context.HttpContext.Response;
response.ContentType = ContentType;
response.AddHeader(ContentDispositionHeaderName, ContentDisposition.ToString());
WriteFile(response);
}
}
In your Controller, or in a base Controller, you can write a simple helper to instantiate a FileContentResultWithContentDisposition and then call it from your action method, like so:
protected virtual FileContentResult File(byte[] fileContents, string contentType, ContentDisposition contentDisposition)
{
var result = new FileContentResultWithContentDisposition(fileContents, contentType, contentDisposition);
return result;
}
public ActionResult Report()
{
// get a reference to your document or file
// in this example the report exposes properties for
// the byte[] data and content-type of the document
var report = ...
return File(report.Data, report.ContentType, new ContentDisposition {
Inline = true,
FileName = report.FileName
});
}
Now the file will be sent to the browser with the file name you choose and with a content-disposition header of "inline; filename=[filename]".
I hope that helps!
The absolute easiest way to stream a file into browser using ASP.NET MVC is this:
public ActionResult DownloadFile() {
return File(#"c:\path\to\somefile.pdf", "application/pdf", "Your Filename.pdf");
}
This is easier than the method suggested by #azarc3 since you don't even need to read the bytes.
Credit goes to: http://prideparrot.com/blog/archive/2012/8/uploading_and_returning_files#how_to_return_a_file_as_response
** Edit **
Apparently my 'answer' is the same as the OP's question. But I am not facing the problem he is having. Probably this was an issue with older version of ASP.NET MVC?
I adapted it in ASP.NET Core with REST API.
public class FileContentWithFileNameResult : FileContentResult
{
public FileContentWithFileNameResult(byte[] fileContents, string contentType, string fileName)
: base(fileContents, contentType)
{
FileName = fileName;
}
public string FileName { get; private set; }
public override Task ExecuteResultAsync(ActionContext context)
{
var response = context.HttpContext.Response;
response.Headers.Append("Content-Disposition", $"inline; filename={FileName}");
response.Headers.Append("Access-Control-Expose-Headers", "Content-Disposition");
response.Headers.Append("X-Content-Type-Options", "nosniff");
return base.ExecuteResultAsync(context);
}
}
public FileContentResult GetImage(int productId) {
Product prod = repository.Products.FirstOrDefault(p => p.ProductID == productId);
if (prod != null) {
return File(prod.ImageData, prod.ImageMimeType);
} else {
return null;
}
}
ASP.NET MVC seems to correctly automatically bind between HTML form's file input field and HttpPostedFileBase. On the other hand it cannot bind from file input field to byte array..I tried and it issues exception - something about not being able to convert to Base64. I had only the byte array property on my Model classes previously because later on I need it to perform serialization of the object into XML file.
Now I've come up with this workaround and it works fine but I am not sure if this will be ok:
[DataContract]
public class Section : BaseContentObject
{
...
[DataMember]
public byte[] ImageBytes;
private HttpPostedFileBase _imageFile;
public HttpPostedFileBase ImageFile
{
get { return _imageFile; }
set
{
_imageFile = value;
if (value.ContentLength > 0)
{
byte[] buffer = new byte[value.ContentLength];
value.InputStream.Read(buffer, 0, value.ContentLength);
ImageBytes = buffer;
ImageType = value.ContentType;
}
}
}
[DataMember]
public string ImageType { get; set; }
}
I think you are letting your Model connect to closely with your Controller. The usual way to do this is:
public ActionResult AcceptFile(HttpPostedFileBase submittedFile) {
var bytes = submittedFile.FileContents;
var model = new DatabaseThing { data = bytes };
model.SaveToDatabase();
}
In this case, there is no need for your Model to be aware of HttpPostedFileBase, which is strictly an ASP.NET concept.
If you need complex binding beyond what the DefaultModelBinder supplies (which is alot), the usual way is to register specialized ModelBinders in Global.asax and then accept your own Model classes as Action Method arguments, like so:
In Global.asax:
ModelBinders.Binders.Add(typeof(MyThing), new ThingModelBinder());
This ModelBinder could then, for example, find any file that was posted with the form and bind the contents of that file to the Data property of your Thing.
And in your Controller:
public ActionResult AcceptThing(MyThing thing) {
thing.Data.SaveToDatabase();
}
In this Action Method, your ThingModelBinder would have handled all binding, making it transparent to both the Controller and the Model.
Modifying your actual Model classes to be aware of, and function with, ASP.NET would not be necessary in this case. Your Model classes are, after all, supposed to represent your actual data.
Apparently there are huge changes (just found it out) in MVC Futures 2, especially regarding Model Binders.
For instance, the problem with my input file binding to byte array, there is a binder now:
• BinaryDataModelBinderProvider – Handles binding base-64 encoded input to byte[] and System.Linq.Data.Binary models.
I have an ASP.NET MVC application where I am displaying images.
These images could be located on the file system or inside a database. This is fine as I can use Url.Action in my image, call the action on my controller and return the image from the relevant location.
However, I want to be able to support images stored in Amazon S3. In this case, I don't want my controller action to return the image, it should instead generate an image URL for Amazon S3.
Although I could just perform this logic inside my view e.g.
<%if (Model.Images[0].ImageLocation == ImageLocation.AmazonS3) {%>
// render amazon image
I need to ensure that the image exists first.
Essentially I need to pass a size value to my controller so that I can check that the image exists in that size (whether it be in the database, file system or amazon s3). Once I am sure that the image exists, then I return the URL to it.
Hope that makes sense,
Ben
Try the following approach.
A model class for an image tag.
public class ImageModel
{
public String Source { get; set; }
public String Title { get; set; }
}
Helper
public static String Image(this HtmlHelper helper, String source, String title)
{
var builder = new TagBuilder("img");
builder.MergeAttribute("src", source);
builder.MergeAttribute("title", title);
return builder.ToString();
}
View with Model.Images of type IEnumerable<ImageModel>
...
<%= Html.Image(Model.Images[0].Source, Model.Images[0].Title) %>
Action
public ActionResult ActionName(/*whatever*/)
{
// ...
var model = ...;
//...
var model0 = ImageModel();
if (Image0.ImageLocation == ImageLocation.AmazonS3)
model0.Source = "an amazon url";
else
model0.Source = Url.Action("GetImageFromDatabaseOrFileSystem", "MyController", new { Id = Image0.Id });
model0.Title = "some title";
model.Images.Add(model0);
// ...
return View(model);
}
An action is a kind of a pseudo code, however the idea should be clear.
After several iterations I have come up with a workable solution, although I'm still not convinced its the best solution.
Originally I followed Anton's suggestion and just set the image url accordingly within my controller action. This was simple enough with the following code:
products.ForEach(p =>
{
p.Images[0].Url = _mediaService.GetImageUrl(p.Images[0], 200);
});
However, I soon found that this approach did not give me the flexibility I needed. Often I will need to display images of different sizes and I don't want to use properties of my model for this such as Product.FullSizeImageUrl, Product.ThumbnailImageUrl.
As far as "Product" is concerned it only knows about the images that were originally uploaded. It doesn't need to know about how we manipulate and display them, or whether we are caching them in Amazon S3.
In web forms I might use a user control to display product details and then use a repeater control to display images, setting the image urls programatically in code behind.
I found that the use of RenderAction in ASP.NET MVC gave me similar flexibility:
Controller Action:
[ChildActionOnly]
public ActionResult CatalogImage(CatalogImage image, int targetSize)
{
image.Url = _mediaService.GetImageUrl(image, targetSize);
return PartialView(image);
}
Media Service:
public MediaCacheLocation CacheLocation { get; set; }
public string GetImageUrl(CatalogImage image, int targetSize)
{
string imageUrl;
// check image exists
// if not exist, load original image from store (fs or db)
// resize and cache to relevant cache location
switch (this.CacheLocation) {
case MediaCacheLocation.FileSystem:
imageUrl = GetFileSystemImageUrl(image, targetSize);
break;
case MediaCacheLocation.AmazonS3:
imageUrl = GetAmazonS3ImageUrl(image, targetSize);
break;
default:
imageUrl = GetDefaultImageUrl();
break;
}
return imageUrl;
}
Html helper:
public static void RenderCatalogImage(this HtmlHelper helper, CatalogImage src, int size) {
helper.RenderAction("CatalogImage", "Catalog", new { image = src, targetSize = size });
}
Usage:
<%Html.RenderCatalogImage(Model.Images[0], 200); %>
This now gives me the flexibility I require and will support both caching the resized images to disk or saving to Amazon S3.
Could do with some url utility methods to ensure that the generated image URL supports SSL / virtual folders - I am currently using VirtualPathUtility.
Thanks
Ben
You can create a HttpWebRequest to load the image. Check the header in the response, if it's 200 that means it was successful, otherwise something went wrong.