ASP.NET Core MVC, Get file from database, and render as image

Question

I have image data being stored in a SQL table with a field type of varbinary(max) I also store the image content type.

Using Microsoft ASP.NET Core MVC an

Answer 1

The below code is just off the top of my head, so it might need some tweaks, but it will give you the basic idea.

Create a new controller and put your methods in there:

public ImageController : Controller
{
    public FileStreamResult GetFile(string FileID)
    {
        return GetFile(new Guid(FileID));
    }

    public FileStreamResult GetFile(Guid FileID)
    {
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();
            DynamicParameters dynamicParameters = new DynamicParameters();
            dynamicParameters.Add(@"ID", FileID);
            FileModel result = connection.Query<FileModel>("GetFile", dynamicParameters, commandType: CommandType.StoredProcedure).FirstOrDefault();
            Stream stream = new MemoryStream(result.FileData);
            return new FileStreamResult(stream, result.FileType);
        }
    }
}

then in your markup, reference the controller:

<img src="@Url.Action("GetFile", "Image", new {FileId = content.FileID})" />

Answer 2

As @fileExtensions.GetFile(content.FileID) actually returns an FileStreamResult it wouldn't be able to render it inside html and probably just returns FileStreamResult.ToString().

Check rendered html!

Instead what you would do is a function that renders an url that triggers an action on an controller which returns the FileStreamResult.

Another alternative is to embed the image if that is what you want.

<img alt="Embedded Image" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADIA..." />

Then you have to encode your image like in this post: Convert image path to base64 string but use your memory stream instead of reading from filepath.