C#

...where [user].username = @username and [user].password = @passwd

try
{
    //some code
}
catch(Exception ex)
{
    //do something with the exception
}
finally
{
    if (reader!=null)
        reader.Close()
}

try
{
	string validateq = "SELECT COUNT(userid) FROM users WHERE username = @username AND password = @passwd ";
	SqlCommand cmd = new SqlCommand(validateq, con);
	cmd.Parameters.AddWithValue("@username", u.UserName);
	cmd.Parameters.AddWithValue("@passwd", u.Password);
	con.Open();
	return Convert.ToInt32(cmd.ExecuteScalar()) > 0;
}
catch (SqlException ex)
{
	throw new Exception(ex.Message,ex) ;
}

Luc Pattyn wrote:

Another reason for a one-vote: one should NOT swallow exceptions,

select count(*) from register where user.username = @username and user.password = @passwd

select count(*) from register where username = @username and password = @passwd

catch (Exception ex)
{
  throw ( new System.Data.DataException ( "validateuser unable to find user " + u.username , ex ) ) ;
}

// Subscribe to the event cell painting
myDataGridView += new DataGridViewCellPaintingEventHandler(myDataGridView_CellPainting);

// Implement the event
void myDataGridView_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
      // Test if you are drawing the picture cell. Note that the RowIndex == 0 is the row header
      if (e.RowIndex > 0 && e.ColumnIndex == 0)
      {
          try
          {
             string strPath = myDataGridView.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString();
             // To optimize you program, you can store the loadeds picture in a dictionary like this:
             Bitmap objPicture = null; 
             if(dicPictures.ContainsKey(strPath))
             {
                  objPicture = dicPictures[strPath];
             }
             else
             {
                  objPicture = Bitmap.FromFile(strPath);
                  dicPictures.Add(strPath, objPicture);
             }

             e.Graphics.DrawImage(objPicture, e.CellBounds);
           }
           catch (Exception Error)
           { 
              // Error Log or Managing
           } 
       }
}