ASP.NET - how to create a simple image downloading page in asp.net

hi everyone....

i want to create a page with full of images and i want that the user can view and download those images.......
how to do so, please help me with some example.......

thanks and ragards
Aman khan

HI
try this

1. Create Captcha Image from random numbers and store that number in session variable, we have used Captcha.aspx page for the same.
2. Use Captcha.aspx as source for the captcha image in Default.aspx page, i.e. for image tag give Captcha.aspx as SRC.
3. On Submit click simply verify captcha entered by user and captcha in session. 

Our folder structure is very simple, check out following image


To understand the way we have checked captcha, have look on HTML of Default.aspx page (Check out http://www.easy-share.com/1912843853/CaptchaInAsp.zip, for better understanding.)

Check out the way we have used Captcha.aspx page in image source.

On submit click we simply checks whether Captcha entered in "txtCaptcha" is valid or not, we have following code for submit button clicked.

protected void btnSubmit_Click(object sender, EventArgs e)
    {
        if (Session["Captcha"] != null)
        {
            if (txtCaptcha.Text == Session["Captcha"].ToString())
            {
                Response.Redirect("RedirectPage.aspx");
            }
            else
            {
                Response.Write("Please Enter Valid Captcha code");
                txtCaptcha.Text = "";
            }
        }
        else
        {
            Response.Write("Session Expired, please re-enter Captcha.");
        }
    }

Now what remains is the logic for Generate captcha image, we don't have any HTML tags on captcha.aspx, we simply write following code for Binary Image Generation and write it. We have used Random number; but we can have our different logic for the same.

protected void Page_Load(object sender, EventArgs e)
    {
        Response.ContentType = "text/plain";
        Random random = new Random(DateTime.Now.Millisecond);

        int number = random.Next(100000);

        Session.Add("Captcha",number.ToString());

        System.Drawing.Bitmap bmpOut = new Bitmap(100, 50);

        Graphics graphics = Graphics.FromImage(bmpOut);

        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;

        graphics.FillRectangle(Brushes.Aquamarine, 0, 0, 100, 50);

        graphics.DrawString(number.ToString(), new Font("TimesNewRoman", 20), new SolidBrush(Color.Coral), 0, 0);

        MemoryStream memorystream = new MemoryStream();

        bmpOut.Save(memorystream, System.Drawing.Imaging.ImageFormat.Png);

        byte[] bmpBytes = memorystream.GetBuffer();

        bmpOut.Dispose();

        memorystream.Close();

        Response.BinaryWrite(bmpBytes);

        Response.End();

    }

refer http://aspdotnetmatters.blogspot.com/2010/11/generate-captcha-image-in-aspnet-simple.html

hello,

here is the code to download any file on button click

hope this will help you

you can use Download Images with a Save As Dialog in ASP.NET refer below link will get source code

http://www.how-to-asp.net/download-images-with-save-as-dialog/

Create a link to a download page like this:

two options you have for that.

For this taks you can display image path in gridView, after that use GridView1_SelectedIndexChanging Event of GridView Control().

I have created Sample example based on your requirement, follow this code-

.ASPX Code-

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"        OnSelectedIndexChanging="GridView1_SelectedIndexChanging">
       <Columns>
         <asp:BoundField DataField="empid" HeaderText="empid" />
         <asp:BoundField DataField="des" HeaderText="des" />
         <asp:BoundField DataField="filename" HeaderText="file" />

         <asp:CommandField  ShowSelectButton="true" />
       </Columns>
     </asp:GridView>

.CS COde

//HERE GETDATA IS A FUCNTION TO GET DATA FROM DATABASE
 
 private void GetData()
    {
      SqlConnection cn = new SqlConnection("CONNECTION STRING");
      cn.Open();
      string strQuery = "Select * from EmpTab";
      SqlDataAdapter da = new SqlDataAdapter(strQuery, cn);
      DataSet ds = new DataSet();
      da.Fill(ds);
 
      GridView1.DataSource = ds.Tables[0];
      GridView1.DataBind(); 
    }

 
protected void GridView1_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
   {
       string filename= GridView1.Rows[e.NewSelectedIndex].Cells[2].Text;

    string path=MapPath("~/soft/" + filename);

    byte []bts=System.IO.File.ReadAllBytes(path);

    Response.Clear();
    Response.ClearHeader();

    Response.AddHeader("Content-Type","Application/octet-stream")
    Response.AddHeader("Content-Length",bts.Length.ToString());
    Response.AddHeader("Content-Disposition","attachment; filename=" + filename);
    Response.BinaryWrite(bts);
    Response.Flush();
    Response.End();

    }

USE THIS CODE AND LET ME KNOW.