using embedded font in all forms

public static class theFont
    {
        [DllImport("gdi32.dll")]
        private static extern IntPtr AddFontMemResourceEx(IntPtr pbFont, uint cbFont, IntPtr pdv, [In] ref uint pcFonts);
       static FontFamily ff;
       static Font font;

        public static Font CargoPrivateFontCollection(float size,FontStyle style)
        {
            // Create the byte array and get its length

            byte[] fontArray = Salary.Properties.Resources.MyFont;
            int dataLength = Salary.Properties.Resources.MyFont.Length;


            // ASSIGN MEMORY AND COPY  BYTE[] ON THAT MEMORY ADDRESS
            IntPtr ptrData = Marshal.AllocCoTaskMem(dataLength);
            Marshal.Copy(fontArray, 0, ptrData, dataLength);


            uint cFonts = 0;
            AddFontMemResourceEx(ptrData, (uint)fontArray.Length, IntPtr.Zero, ref cFonts);

            PrivateFontCollection pfc = new PrivateFontCollection();
            //PASS THE FONT TO THE  PRIVATEFONTCOLLECTION OBJECT
            pfc.AddMemoryFont(ptrData, dataLength);

            //FREE THE  "UNSAFE" MEMORY
            Marshal.FreeCoTaskMem(ptrData);

            ff = pfc.Families[0];
           return font = new Font(ff,size, style);
        }
    }

/////////////Font///////////
   foreach (Control cx in this.Controls)
       cx.Font = theFont.CargoPrivateFontCollection(9f, FontStyle.Regular);

"system.drawing.Graphics Object is currently in use elsewhere"