How to create a thumbnail

Newton111 · September 25th, 2015, 08:49 AM

At the end of chapter 14 you said something about performance issues. You said we should create a thumbnail at the server before previewing it in the browser. And you referred as to read instant Asp.net 2.0 under the greeting cards chapter to learn how to create a thumbnail. But unfortunately for me the code was in visual basic and not c-sharp. So I was wondering if you could help me to create a thumbnail when the user uploads an image at the server before displaying it in the browser.
This is the code to upload an image to the server.

Code:

    protected void EntityDataSource1_Inserting(object sender, EntityDataSourceChangingEventArgs e)
    {
        /*
        Gets the querystring from the page and insert it into the picture table
        under the PhotoAlbumId  column
        */
        int photoAlbumId = Convert.ToInt32(Request.QueryString.Get("PhotoAlbumId"));
        Picture myPicture = (Picture)e.Entity;
        myPicture.PhotoAlbumId = photoAlbumId;

        /*
        Uploading the picture to the file server and save it reference to the 
        database under the imageUrl column.
        Also performing some validations

        */
       
        FileUpload FileUploaded1 = (FileUpload)ListView1.InsertItem.FindControl("FileUpload1");
        string virtualFolder = "~/GigPics/";
        string physicalFolder = Server.MapPath(virtualFolder);
        string fileName = Guid.NewGuid().ToString();
        string extension = System.IO.Path.GetExtension(FileUploaded1.FileName);
        FileUploaded1.SaveAs(System.IO.Path.Combine(physicalFolder, fileName + extension));
        myPicture.ImageUrl = virtualFolder + fileName + extension;

    
    }

Imar · September 28th, 2015, 03:30 PM

Hi there,

It's a bit too much to write the entire implementation for you. May I recommend http://converter.telerik.com/ to convert form VB to C#? Then feel free to post follow up questions here. Or better, in the General ASP.NET category here: http://p2p.wrox.com/asp-net-4-5-709/ since it's not book specific.

Cheers,

Imar

Newton111 · September 29th, 2015, 05:40 PM

Thanks and I have been able to solve the issue by convert the VB to C# using the provided link.
But now how can I use Listview and Data Pager controls together with Linq's Skip and Take methods to limit the amount of data that is sent to the browser ??

Imar · October 4th, 2015, 11:25 AM

Hi there,

Search Google for ASP.NET Model Binding which will show you how to use LINQ and the data controls. My 4.5.1. book shows how this works too.

Cheers,

Imar

Newton111 · October 5th, 2015, 03:32 PM

Thanks a lot for your reply I have been able to solve the problem.

Newton111 · October 5th, 2015, 05:26 PM

I was wondering if you could give me some ideas on how to search items in your database and send the results to an aspx page. For instance when you use the search textbox in www.wrox.com to search an item, after the item is found, it sends the results to the search page.
Like this
http://www.wrox.com/WileyCDA/Section...tml?query=c%23

Imar · October 6th, 2015, 03:09 AM

Hi there,

It's better to start a new thread for new topics. Your new question is unrelated to thumbnails so it would have been better of as a separate subject.

That said, here's what I would do:

1. Add a text box and button to your page. On click of the button, redirect the user to the search results with the search terms in the Query String. Something like this:

Response.Redirect(string.Format("Search.aspx?terms ={0}"), SearchBox.Text);

2. In Search.aspx, search the database using the passed in query string terms. You can either hook up a SqlDataSource control with a query string parameter, or use something like LINQ and model binding to get the data and show it on the page.

Hope this helps,

Imar

Newton111 · October 6th, 2015, 02:14 PM

Thanks for the reply