This code uploads an image to the server file system.  If the image is wider than a certain width it resizes the image.  The image is saved as a jpg.

        // Upload image
        // Make sure to create directory if needed.
        string savePath = Server.MapPath("~/UploadFolder/");

        // Create Directory if it doesn't exist
        if (!System.IO.Directory.Exists(savePath))
        {
            System.IO.Directory.CreateDirectory(savePath);
        }


        // Declare some image variables
        System.Drawing.Image imgOriginal;  // Will hold the original image
        System.Drawing.Image imgNew;  // Will hold the new image
        double targetWidth = 100; // Default target width for new image
        double targetHeight = 100; // Default target height for new image

        // Get new width from config
        try
        {
            targetWidth = Convert.ToDouble(ConfigurationManager.AppSettings["MaxImageWidth"]);
        }
        catch
        {
            targetWidth = 100;
        }

        //Create a new Image using the uploaded picture as a Stream
        imgOriginal = Bitmap.FromStream(ImageUpload.PostedFile.InputStream);

        // Work out a proportionate height from width
        if ((double)imgOriginal.Width < targetWidth)
        {
            targetWidth = (double)imgOriginal.Width;
            targetHeight = (double)imgOriginal.Height;
        }
        else
        {
            targetHeight = (double)imgOriginal.Height / ((double)imgOriginal.Width / targetWidth);
        }

        // Now create the new image
        imgNew = new Bitmap(imgOriginal, (int)targetWidth, (int)targetHeight);

        // Save it to the file system as a jpg.
        imgNew.Save(savePath + "\\" + pAdID.ToString() + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
 

The following will validate stringVariable to see if it matches an email pattern.

System.Text.RegularExpressions.Regex.IsMatch(stringVariable, "\\w+([-+.']\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*");

There are double \ due to the language being C#.

This code inserts a record into the database using a DataSet. Using this method you don't need to know SQL and have more control over how things are inserted. Good for adding or updating records.

Normally when you click on a link to a file the browser will try to read or open that file automatically. This code will force the browser to open the "Save As..." dialog box using a swf file as an example.

<script runat="server">
private void Page_Load(object sender, System.EventArgs e)
{
  Response.ContentType = "application/x-shockwave-flash";
  Response.AppendHeader("content-disposition","attachment; filename=button1.swf");
  Response.WriteFile((string)MapPath("button1.swf"));
  Response.End();
}
</script>

This tech note shows how to compile a C# source file using the command line and tools provided with the .NET SDK

This code snippet shows examples of DateTime and TimeSpan. It also shows how to subtract dates and timespans.