TweetDuck/Core/Controls/LabelVertical.cs

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

namespace TweetDuck.Core.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;
                }
            }
        }
    }
}