Write image to page with different name - c#

I am trying to implement a simple captcha system and I wish to output an image without using its original name.
For example I would like to ouput the image file 8.gif to the page with the name captcha1.gif
I have read the various posts but I am looking for the simplest solution.
Here's what I have so far...
<% Html.RenderAction("OuputCaptchaImage", "Home", new { imageName = "1" }); %>
public ActionResult OuputCaptchaImage(string imageName)
{
var dir = Server.MapPath("images/");
var path = Path.Combine(dir, imageName + ".gif"); // Like to change name here
return base.File(path, "image/gif");
}
and what I would like to render to the page
<img src="image/captcha1.gif" />

The following mark-up will output the image correctly. However you still have the problem of the file name being referenced in the url.
<img src="<%= Url.Action("OuputCaptchaImage", "Home", new { imageName = "1" })%>" />
Which would output the following HTML:
<img src="/Home/OuputCaptchaImage?imageName=1" />
You could specify some other value as a parameter such as an enumeration rather than the image name, and then modify your logic to return the correct file.
However (AFAIK) to output an image with a file name which does not exist would require an Httphandler to intercept the request and write out the image you require to the response stream.
Edit
Here is an example of using an HttpHandler to intercept the incoming request for "captcha1.gif" and streaming a different image to the response:
Mark-up
<img src="Images/captcha1.gif" />
HttpHandler
public class OuputCaptchaImageHandler : IHttpHandler
{
public bool IsReusable
{
get
{
return false;
}
}
public void ProcessRequest(HttpContext context)
{
string imagePath =
context.Server.MapPath(#"~\Images\1.gif");
Bitmap bitmap = new Bitmap(imagePath);
context.Response.ContentType = "image/gif";
bitmap.Save(context.Response.OutputStream, ImageFormat.Gif);
bitmap.Dispose();
}
}
Web.Config
<httpHandlers>
<add verb="*" path="Images/captcha1.gif" type="FullyQualifiedNameSpace.OuputCaptchaImageHandler, RootNamespace" validate="false"></add>
</httpHandlers>
Global.asax.cs
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("Images/captcha1.gif/{*pathInfo}");
....
Hope this helps.

Related

ASP.NET MVC image from byte array

currently I have a byte array representing my Image in my ViewModel. I display it with the following code:
<img src="#String.Format("data:image/gif;base64,{0}", Convert.ToBase64String(Model.Image))" />
Now I don't want to have a Base64 String in my Source file, but rather a link to a image. Like:
<img src="Images/" + Model.Id"/>
which would return a Image.
How do I write such a method to return a Image link?
You could define a controller action that will serve the image:
public class ImagesController: Controller
{
public ActionResult Index(int id)
{
byte[] imageData = ... go get your image data from the id
return File(imageData, "image/png"); // Might need to adjust the content type based on your actual image type
}
}
and in your view simply point the src property of the img tag to this controller action:
<img src="#Url.Action("Index", "Images", new { id = Model.Id })" />
One way is to add this to a new c# class or HtmlExtensionsclass
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("<img src='" + img + "' />");
}
}
then you can do this in any view
#Html.Image(Model.MyImageBytes)

Return string value in Action to put it in Src of img tag

This is my part of View:
<img src="#{Html.RenderAction("GetUserProfileImage", "Home", new { area = "" });}" alt="" />
And My Controller:
public ActionResult GetUserProfileImage() {
string defaultresult = "http://MyProject.dev/Content/img/sample_user.png";
if (Member.LogIn()) {
DBFile file = GetMemberPicFromDB();
return File(file.Content, file.ContentType);
} else {
return Content(defaultresult);
}
}
So when I Get File from DB every thing is OK, but when I return URL(by return Content) there is some bad result in rendered html, something like this:
<imghttp: myproject.dev="" content="" img="" sample_user.png="" src="" alt="">
<div>
some content from outside of img tag added here
</div>
</imghttp:>
Also I change the View to:
<img src="http://myproject.dev/Content/img/sample_user.png" alt="" />
And every thing is OK,
So where is the problem? it seems return Content can not return simple string to src attribute, So what is your suggestion for return simple string?
if that not possible
I think to get File by URL(http://myproject.dev/Content/img/sample_user.png) and return File() Like when returned from DB, but how can I get the file in controller by this URl(http://myproject.dev/Content/img/sample_user.png) ?
and any other suggestion if you have?
You should return a file from your controller action in both cases and reference this action in your image, like this:
<img src="#Url.Action("GetUserProfileImage", "Home", new { area = "" })" alt="" />
and then in your controller action return a File result in both cases:
public ActionResult GetUserProfileImage()
{
if (Member.LogIn())
{
DBFile file = GetMemberPicFromDB();
return File(file.Content, file.ContentType);
}
else
{
string image = Server.MapPath("~/content/img/sample_user.png");
return File(image, "image/png");
}
}

set src property in view to a url outside of the MVC3 project

I am trying to create an application that will display images that are stored locally on the webserver. Here is what I have in my view, note that "entry" are absolute addresses like "C:\Images\Image1.jpg". However, when I run it, I get "Not allowed to load local resource: file:///C:/Images/ImageName.jpg" in the console log. So maybe it tries to access the image on the client. How do I tell my view to access the local webserver path and not look for the image source on the client? Please note that moving the images into project directory is not an option, because the images are stored on a different drive on the webserver.
<!-- language: c# -->
#model List<String>
<div style="height: 500px; overflow:scroll;">
<h2>
ScreenShots for testMachine</h2>
#foreach (var entry in Model)
{
<div class="nailthumb-container square-thumb">
<img alt="screenshot" src="#Url.Content(entry)" />
</div>
}
</div>
You cannot directly serve images outside of your ASP.NET MVC 3 application to the client. That would be a huge security vulnerability if the client could access arbitrary files on your server.
You will need to write a controller action that will return them and then point your src property of your <img> tags to this controller action.
public class ImagesController: Controller
{
public ActionResult SomeImage()
{
return File(#"C:\Images\foo.jpg", "image/jpeg");
}
}
and inside your view:
<img src="#Url.Action("SomeImage", "Images")" alt="" />
You could also pass the image name as parameter to the controller action:
public class ImagesController: Controller
{
public ActionResult SomeImage(string imageName)
{
var root = #"C:\Images\";
var path = Path.Combine(root, imageName);
path = Path.GetFullPath(path);
if (!path.StartsWith(root))
{
// Ensure that we are serving file only inside the root folder
// and block requests outside like "../web.config"
throw new HttpException(403, "Forbidden");
}
return File(path, "image/jpeg");
}
}
and in your view:
<img src="#Url.Action("SomeImage", "Images", new { image = "foo.jpg" })" alt="" />
The above code was useful for me, with a change like this
System.Web.UI.Page page = new System.Web.UI.Page();
string filePath = page.Server.MapPath("~/Log/" + fileName);
if (!filePath.StartsWith(filePath))
{
throw new HttpException(403, "Forbidden");
}
return File(filePath, "Content-Disposition", "attachment;filename=TableImportLog.csv");
}
the file thrown to the user is with file name like this "attachment;filename=TableImportLog.csv", but i want the file name as "TableErrorLog.csv"
need help for the same!

How do I load an image from a database in ASP.NET MVC?

I have saved an image on the database and want to display it to the user.
The table the image is stored in looks like this:
Images
------
ImageData Byte
ImageName String
ContentType String
What should I do to load and show it in my View?
In Image controller class:
public ActionResult ProfileImage(string userName)
{
var imageByteArray = // get image bytes from DB corresponding to userName
string contentType = // get image content type from DB for example "image/jpg"
string fileName = // get image file name from DB
return File(imageByteArray, contentType, fileName);
}
In view:
<img src='/Image/ProfileImage/yourUserName' alt='Profile image' />
You'll also need a custom route in Global.asax:
routes.MapRoute(
"ProfileImage",
"Image/ProfileImage/{userName}",
new { controller = "Image", action = "ProfileImage", userName = "" }
);
You can also load the image in Bitmap and apply changes like resizing, rotation and so on. If you do that consider saving the image as png since GDI+ (System.Drawing) can keep best quality and transparency with this format. It is also good practice to cache dynamic images.

ASP.NET MVC: Can't figure out what VirtualPath is?

I have a View that displays a list of images and i am now trying to get it to display the images as thumbnails. Well, i'm pretty sure i got most of it right using VirtualPath's from a custom ActionResult although i can't seem to figure out what it is making the VirtualPath url?? BTW, i'm using XML to store the data from the images instead of SQL. Here is my code:
Code from my custom ActionResult:
public class ThumbnailResult : ActionResult
{
public ThumbnailResult(string virtualPath)
{
this.VirtualPath = virtualPath;
}
public string VirtualPath { get; set; }
public override void ExecuteResult(ControllerContext context)
{
context.HttpContext.Response.ContentType = "image/bmp";
string fullFileName =
context.HttpContext.Server.MapPath("~/Galleries/WhereConfusionMeetsConcrete/" + VirtualPath);
using (System.Drawing.Image photoImg =
System.Drawing.Image.FromFile(fullFileName))
{
using (System.Drawing.Image thumbPhoto =
photoImg.GetThumbnailImage(100, 100, null, new System.IntPtr()))
{
using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
{
thumbPhoto.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
context.HttpContext.Response.BinaryWrite(ms.ToArray());
context.HttpContext.Response.End();
}
}
}
}
}
Code for my Controller:
public ActionResult Thumbnail(string id)
{
return new ThumbnailResult(id);
}
Code for my View:
<% foreach (var image in ViewData.Model) { %>
<img src="../Galleries/TestGallery1/thumbnail/<%= image.Path %>" alt="<%= image.Caption %>" />
<br /><br /><%= image.Caption %><br /><br /><br />
<% } %>
Any help would be greatly appreciated!! Let me know of any questions you have as well. :) Thanks!
From what I can see you are using the VirtualPath string member in the ThumbnailResult custom action to identify the last portion of the image url. So for example if your site is located at c:\wwwroot\Galleries\WhereConfusionMeetsConcrete and the image files are located inside this folder like image1.bmp, image2.bmp, ... you could only pass the image filename to the custom action result constructor which is called in the controller action and passed the id parameter. So in order to show a thumbnail for image1.bmp in your view you could do this:
<img src="<%= Url.RouteUrl(new { controller = "home", action = "Thumbnail", id = "image1.bmp" }) %>" alt="" />
Of course this assumes that you have a default route like this:
routes.MapRoute(
"Default",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);

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