TweetDuck/Controls/LabelVertical.cs

using System;
using System.Drawing;
using System.Windows.Forms;

namespace TweetDuck.Controls{
    sealed class LabelVertical : Label{
        public int LineHeight { get; set; }

        protected override void OnPaint(PaintEventArgs e){
            int y = (int)Math.Floor((ClientRectangle.Height - Text.Length * LineHeight) / 2F) - 1;
            using Brush brush = new SolidBrush(ForeColor);

            foreach(char chr in Text){
                string str = chr.ToString();
                float x = (ClientRectangle.Width - e.Graphics.MeasureString(str, Font).Width) / 2F;

                e.Graphics.DrawString(str, Font, brush, x, y);
                y += LineHeight;
            }
        }
    }
}