CODEWITHSUNDEEP
c#asp.net-web-api
cwineman
cwineman

Reputation: 31

ASP.NET Web API to return images

I've been spinning my tires trying to use ASP.NET Web API to return images. I've seen a number of examples, but I keep running into problems.

After searching for a solution, most examples suggest using HttpResponseMessage and setting the Content and Content-Type header correctly. For example in the following posts: WebApi: How to handle Images ASP .Net Web API downloading images as binary

Here's what I am doing now:

    [System.Web.Http.HttpGet]
    [ActionName("ConvertHTMLToImage")]
    public HttpResponseMessage ConvertHTMLToImage(string htmlString)
    {
        var path = @"C:\temp\mona-lisa.png";
        var response = Request.CreateResponse(HttpStatusCode.OK);
        var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);
        response.Content = new StreamContent(fileStream);
        response.Content.Headers.ContentType = new MediaTypeHeaderValue("image/png");
        return response;
    }

I'm getting mixed results. When I go the URL for that resource I have problems with Chrome (This webpage is not available), Firefox (The connection was reset), and Safari (Safari can’t open the page). Much to my surprise, it works fine in IE. I can also successfully view the image using the composer in Fiddler. If I keep Fiddler open and access the resource using Chrome/Firefox/Safari, I see 504 errors. Not sure what the means, I can't remember ever having seen that error type before.

I also noticed some strange behavior in the debugger with the browsers that aren't working. If I call ConvertHTMLToImage from IE and Fiddler, I see it stop at my break-point once and then the image is sucessfully returned to the client. On Chrome/Firefox/Safari there are multiple calls into the method. Sometimes twice sometimes 3 times. I have no explanation for this. I don't get any errors that I can detect other than the browser doesn't show the image.

I've done this same thing using aspx pages, HttpHhandlers, and other .NET methods so I know there are work-arounds, but I really would like to know what I'm doing wrong. This seems like something that should be easily accomplished using the Web API.

Upvotes: 3

Views: 13092

Answers (3)

Pablo Retyk
Pablo Retyk

Reputation: 5750

This solved the issue for me WebApi: How to handle Images

In short

[System.Web.Http.HttpGet]
[ActionName("ConvertHTMLToImage")]
public HttpResponseMessage ConvertHTMLToImage()
{  
     string filePath = @"C:\temp\mona-lisa.png";

     var result = new HttpResponseMessage(HttpStatusCode.OK);

     FileStream fileStream = new FileStream(filePath, FileMode.Open);
     Image image = Image.FromStream(fileStream);
     MemoryStream memoryStream = new MemoryStream();
     image.Save(memoryStream, ImageFormat.Jpeg);

     result.Content = new ByteArrayContent(memoryStream.ToArray());
     result.Content.Headers.ContentType = new  MediaTypeHeaderValue("image/jpeg");
     return result;
}

Upvotes: 5

Syed Waqas
Syed Waqas

Reputation: 2676

Try this(replace jpg with png as desired):

var result = new HttpResponseMessage(HttpStatusCode.OK);    
String filePath = HostingEnvironment.MapPath("~/Images/123.jpg");
FileStream fileStream = new FileStream(filePath, FileMode.Open);
Image image = Image.FromStream(fileStream);
MemoryStream memoryStream = new MemoryStream();
image.Save(memoryStream, ImageFormat.Jpeg);
var byteArrayContent = new ByteArrayContent(memoryStream.ToArray());
byteArrayContent.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg");
result.Content = byteArrayContent;
return result;

Upvotes: 0

user1846366
user1846366

Reputation: 76

I used this recently in my project:

public HttpResponseMessage Get(int IRN)
        {
            try
            {
                Multimedia image = new Multimedia();
                MemoryStream imageStream = image.GetMedia(IRN);
                HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
                response.Content = new StreamContent(imageStream);
                response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/jpeg");
                return response;
            }
            catch (Exception ex)
            {
                return HandleError(ex);           
            }

        }

GetMedia function:

    .....
                MemoryStream mediaStream = new MemoryStream();
    ...
    FileStream temp = resource["file"] as FileStream;
                            mediaStream.SetLength(temp.Length);
                            temp.Read(mediaStream.GetBuffer(), 0, (int)temp.Length);

                            temp.Close();
....

  return mediaStream;

resource["file"] is an array which contained a filestream object.

Hope this helps.

Upvotes: 0

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