Adding a preview section in ASP.NET web application

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
using System.IO;
using System.Drawing;
namespace imageResize1
{
    public partial class _Default : System.Web.UI.Page
    {
        string Strcon = ConfigurationManager.ConnectionStrings["con"].ConnectionString;
        protected void Page_Load(object sender, EventArgs e)
        {
            
        }
        protected void Button1_Click(object sender, EventArgs e)
        {
                ProcessedImage();
        }
        private void ProcessedImage()
        {
            try
            {
                if (FileUpload1.HasFile)
                {
                    int length = 192;
                    int width = 192;
                    using (Bitmap sourceImage = new Bitmap(FileUpload1.PostedFile.InputStream))
                    {
                        using (Bitmap resizedImage = new Bitmap(length, width))
                        {
                            using (Graphics graphics = Graphics.FromImage(resizedImage))
                            {
                                graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
                                graphics.SmoothingMode = SmoothingMode.HighQuality;
                                graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
                                graphics.DrawImage(sourceImage, 0, 0, length, width);
                            }
                            string resizedImagePath = Server.MapPath("~/Images/finalImage.png");
                            resizedImage.Save(resizedImagePath, ImageFormat.Png);
                            ImgPhoto.ImageUrl = "~/Images/finalImage.png";
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                string errorMessage = "An error occurred " + ex.Message;
            }
        }         
    }
}

In the code I have an asp button which on clicked shows the uploaded and resized image in the asp image box. Is it possible to preview the image without clicking the Show button (Button1)? i.e is it possible to make the image visible directly without clicking the button1? I am developing the web application in Visual Studio 2010. It is an ASP.NET Web Application. So it won't support any javascript code.

Well, we have a user selecting a file, then hitting a button to upload the file, then code behind processes that file, and then you display that processed file.

If you don't want the user to have to hit submit to up-load the file, then you can adopt a asynchronous file upload control. When they select the file, it will automatic up-load upon that selecting and no submit button is required. this will also trigger the code behind to run. However, since no post-back is occurring, that code behind can process the file, but it will not be able to update the image control. However, the async file uploader when done can trigger a client side bit of code. That bit of code can either get the new source path and update the image control, or you could even have the client side JavaScript code click/trigger a button to update the image control.

So, you could consider adopting and using a different file up-load control. There is a async file uploader in the ajaxtoolkit, which would and should be compatible with your existing code and site.