To enable double buffering on a control without subclassing it, use the method below. Double buffering is disabled in terminal server sessions since it will lower performance instead of increasing it.

public static void setDoubleBuffering(Control control, bool state)
{
   if (!System.Windows.Forms.SystemInformation.TerminalServerSession)
   {
      typeof(Control).InvokeMember("DoubleBuffered",
      System.Reflection.BindingFlags.NonPublic |
      System.Reflection.BindingFlags.Instance  |
      System.Reflection.BindingFlags.SetProperty,
      null,
      control, new object[] { state });
   }
}

Using DrawString texts have a horizontal spacing depending on their font size. In case of a list using multiple font sizes this looks strange. To start exactly at the same space use the following as a StringFormat argument for DrawString

StringFormat sFormat = new StringFormat(StringFormat.GenericTypographic);

To execute a post-build command Visual C++ offers settings for both debug and release mode. Visual C# does not. To execute a post-build command based on debug or release mode use the following construct:

if $(ConfigurationName) == Release d:\test.exe $(TargetPath)

To show time in a DataGridView column set the column type to DataGridViewTextBoxColumn.
Set the columns DefaultCellStyle Format to ‘t’. You can do this in the designer or use the following code:

myGridView.Columns[0].DefaultCellStyle.Format = “t”; //0 is the required column, change if needed.

Now you can assign a DateTime to the cell value and time will show in the users preferred format (‘t’).

When in need of a simple double buffered panel, considering using a PictureBox instead. It is double buffered by default.

When using modeless forms the user can close  the form manually. Use the created property to check whether this is the case.

Example:

class Form1 : Form
{
   Form2 modelessForm = null;

   //On mouse click show Form2
   void onMouseClick(MouseButtons button, int x, int y)
   {
      if (modelessForm == null || !modelessForm.Created)
      {
         modelessForm = new Form2()
      }

      modelessForm.Show();
   }
}

When parsing a value out of a string the current separator is used. In English this is a dot. In other languages a comma is being used.
When parsing a string the current culture setting is being used!

To ensure the dot is being used as separator use the method below:

double value = Convert.ToDouble(text, CultureInfo.InvariantCulture);

Self explanatory snippet

SqlConnection db = new SqlConnection(Properties.Settings.Default.ConnectionString);

try
{
   db.Open();

   SqlCommand cmd = new SqlCommand("storedProcedureName", db);
   cmd.CommandType = CommandType.StoredProcedure;
   cmd.Parameters.Add(new SqlParameter("@parm1", SqlDbType.Int, 4));
   cmd.Parameters.Add(new SqlParameter("@parm2", SqlDbType.Text));
   cmd.Parameters["@parm1"].Value = 1234;
   cmd.Parameters["@parm2"].Value = "ABC";

   SqlDataReader dataReader = cmd.ExecuteReader();

   DataTable storedTable = new DataTable();
   storedTable.Load(dataReader);
                
   foreach (DataRow row in storedTable.Rows)
   {
      //Here row contains the retrieved data.
      int test = Convert.ToInt32(row[0]);
   }
   storedTable.Dispose();
   dataReader.Dispose();
   cmd.Dispose();
          
   db.Close(); 
   db.Dispose(); 
   db = null;
}
catch (Exception e)
{
   System.Windows.Forms.MessageBox.Show(e.Message, "DB error", System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error);      
}