Upload with Thumbnail Generator in ASP.NET and C#

This tutorial will show how we use the FileUpload Control to upload a file to the website, whilst simultaneously creating a thumbnail of the image, and saving that too. C# version.


In this tutorial, we will create a single file upload form and a GridView to display the list of uploaded files.
The upload form will upload a single file at a time, when the user click the button, and it will also create a thumbnail of the image, saving both images to the uploads folder.

Add AddImages.aspx

Design side
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<table width="100%" cellspacing="5">
        <tr>
            <td>
                <h3>
                    Add Images</h3>
            </td>
            <td>
                &nbsp;
            </td>
        </tr>
        <tr>
            <td width="120px" colspan="2">
                <asp:Label ID="lbl_msg" runat="server" ForeColor="Red"></asp:Label>
            </td>
        </tr>
      
        </tr>
        <tr>
            <td>
                Image Name :
            </td>
            <td>
                <asp:TextBox ID="txtFilename" runat="server"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                New Image:
            </td>
            <td>
                <asp:FileUpload ID="fupAddVideo" runat="server" />
            </td>
        </tr>
        <tr>
            <td>
                &nbsp;
            </td>
            <td>
                &nbsp;
            </td>
        </tr>
        <tr>
            <td>
                &nbsp;
            </td>
            <td>
                <asp:Button ID="btn_Save" runat="server" OnClick="btn_Save_Click" Text="Save" OnClientClick="return ValidateControls()"
                    Width="80px" />
            </td>
        </tr>
    </table>
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In the code behind
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DC;
using BL;
using System.IO;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Diagnostics;
using System.Data;


public partial class AddImages : System.Web.UI.Page
{

    string postedfilename, SavePath, Filenamewithpath;



protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
        
        }
    }


 protected void btn_Save_Click(object sender, EventArgs e)
{


    if (fupAddVideo != null || fupAddVideo.PostedFile != null)
        {
            postedfilename = fupAddVideo.PostedFile.FileName;
            SavePath = AppDomain.CurrentDomain.BaseDirectory + "Images\\" + "Photos\\";
            string NewFName = postedfilename;
            NewFName = NewFName.Substring(NewFName.LastIndexOf("\\") + 1, NewFName.Length -    NewFName.LastIndexOf(".")) + "." + NewFName.Substring(NewFName.LastIndexOf(".") + 1);
            Filenamewithpath = SavePath  + NewFName;

            //Save The file
            fupAddVideo.PostedFile.SaveAs(Filenamewithpath);

            //Start Converting
            string  outputfile;
            string withoutext;

            //Get the file name without Extension
            withoutext = Path.GetFileNameWithoutExtension(Filenamewithpath);

        outputfile = SavePath   + withoutext + ".JPG";

            Session["outputfile"] = withoutext + ".JPG";

//Creating Thumbnail

        System.Drawing.Image image =   System.Drawing.Image.FromStream(fupAddVideo.PostedFile.InputStream);

        float imgWidth = image.PhysicalDimension.Width;

        float imgHeight = image.PhysicalDimension.Height;

        float imgSize = imgHeight > imgWidth ? imgHeight : imgWidth;

        float imgResize = imgSize <= 128 ? (float)1.0 : 128 / imgSize;

        imgWidth *= imgResize; imgHeight *= imgResize;

        System.Drawing.Image thumb = image.GetThumbnailImage((int)imgWidth, (int)imgHeight, delegate() {  return false; }, (IntPtr)0);

          string ThumbName =AppDomain.CurrentDomain.BaseDirectory + "Images\\"+"Thumb\\";

          

            string thumbpath;

            thumbpath = ThumbName + withoutext + "1" + ".jpg";

             if (File.Exists(thumbpath))

                 File.Delete(thumbpath);

             thumb.Save(thumbpath);

          Session["thumbname"] = withoutext + "1" + ".jpg";

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