How does Url.Action work Asp.net MVC?

问题

This is somewhat related to another question I've asked but I figure why not ask it seperately.

If I were to place something like the following in a view

<td><img src='<%= Url.Action( "DisplayImage" , "User" , new { id = item.id} ) %>' alt="" /></td>

Is it supposed to display this?

<td>
   <img src='/User.mvc/DisplayImage?id=U00915441' alt="" />
</td>

Or would the value of the src-attribute actually be replaced with the results of the UserController GetImage Action?

回答1:

It will construct the path to the action, returning a url, not the results of executing the action.

The results will be:

<td>
   <img src='/User.mvc/DisplayImage?id=U00915441' alt="" />
</td>

Example code. assumes your user model has the image stored in a byte array. If you are using LINQ and the property is a Binary, then use the ToArray() method to convert it to a byte array. Note the attributes which will require that the user be logged in and using a GET request.

[Authorize]
[AcceptVerbs( HttpVerbs.Get )]
public ActionResult DisplayImage( string id )
{
     var user = ...get user from database...

     return File( user.Image, "image/jpeg" );
}

}

来源：https://stackoverflow.com/questions/1759189/how-does-url-action-work-asp-net-mvc