C# 自定义设定字体间距

using System.Drawing;
using System.Drawing.Drawing2D;
using System.Runtime.InteropServices;
using System.Reflection;

namespace GdiplusMethods

{
   public  class GdiplusMethods
    {
        private GdiplusMethods() { }
        private enum DriverStringOptions
        {
            CmapLookup = 1,
            Vertical = 2,
            Advance = 4,

            LimitSubpixel = 8,
        }
        public static void DrawDriverString(Graphics graphics, string text,
        Font font, Brush brush, PointF[] positions)
        {
            DrawDriverString(graphics, text, font, brush, positions, null);
        }
        public static void DrawDriverString(Graphics graphics, string text,
        Font font, Brush brush, PointF[] positions, Matrix matrix)
        {
            if (graphics == null)
                throw new ArgumentNullException("graphics");
            if (text == null)
                throw new ArgumentNullException("text");
            if (font == null)
                throw new ArgumentNullException("font");
            if (brush == null)
                throw new ArgumentNullException("brush");
            if (positions == null)
                throw new ArgumentNullException("positions");
            // Get hGraphics
            FieldInfo field = typeof(Graphics).GetField("nativeGraphics",
            BindingFlags.Instance | BindingFlags.NonPublic);
            IntPtr hGraphics = (IntPtr)field.GetValue(graphics);
            // Get hFont
            field = typeof(Font).GetField("nativeFont",
            BindingFlags.Instance | BindingFlags.NonPublic);
            IntPtr hFont = (IntPtr)field.GetValue(font);
            // Get hBrush

            field = typeof(Brush).GetField("nativeBrush",
            BindingFlags.Instance | BindingFlags.NonPublic);
            IntPtr hBrush = (IntPtr)field.GetValue(brush);
            // Get hMatrix
            IntPtr hMatrix = IntPtr.Zero;
            if (matrix != null)
            {
                field = typeof(Matrix).GetField("nativeMatrix",
                BindingFlags.Instance | BindingFlags.NonPublic);
                hMatrix = (IntPtr)field.GetValue(matrix);
            }
            int result = GdipDrawDriverString(hGraphics, text, text.Length,
            hFont, hBrush, positions, (int)DriverStringOptions.CmapLookup, hMatrix);
        }
        [DllImport("Gdiplus.dll", CharSet = CharSet.Unicode)]
        internal extern static int GdipMeasureDriverString(IntPtr graphics,
        string text, int length, IntPtr font, PointF[] positions,
        int flags, IntPtr matrix, ref RectangleF bounds);
        [DllImport("Gdiplus.dll", CharSet = CharSet.Unicode)]
        internal extern static int GdipDrawDriverString(IntPtr graphics,
        string text, int length, IntPtr font, IntPtr brush,
        PointF[] positions, int flags, IntPtr matrix);
    }
}

            //オブジェクトを取得します。
            Graphics g = e.Graphics;
           string  sPrint =“但是dssadfSS”；

           float  LeftMargin =5.0f;

           float  topMargin =5.0f;

                        for (int n = 0; n < sPrint.Length; n++ )
                        {
                            string fortext = sPrint.Substring(0, n);
                           int XPos = Encoding.Default.GetBytes(fortext).Length;
                            positions[n] = new PointF(XPos * (fnt.Size - 5.0f) + LeftMargin, topMargin + ((count + m) * fnt.GetHeight(g)));

                        }   //行の表示位置を計算
                        GdiplusMethods.DrawDriverString(g, sPrint, fnt, Brushes.Black, positions);