private void Form1_Load(object sender, EventArgs e)
{
    using (PrivateFontCollection pfc = new PrivateFontCollection())
    {
        pfc.AddFontFile(@"E:\xjl.ttf");
        Font font = new Font(pfc.Families[0], 36, GraphicsUnit.Pixel);
        button1.Font = font;
    }
}