C# 实现文字生成透明背景图片

        /// <summary>
        /// 文字转透明背景图片
        /// </summary>
        /// <param name="text">文字</param>
        /// <param name="filename">保存路径</param>
        public static void TextToImage(string text, string filename)
        {
            int fontSize = 48;//字体大小
            Font f = new Font("宋体", fontSize); //字体
            Graphics g = Graphics.FromImage(new Bitmap(1, 1));
            SizeF sf = g.MeasureString(text, f);//测量出字体的高度和宽度
            //初始化图片
            Bitmap b = new Bitmap(Convert.ToInt32(sf.Width), Convert.ToInt32(sf.Width));
            Brush whiteBrush = new SolidBrush(Color.White); //画笔颜色
            try
            {
                //创建画布
                g = Graphics.FromImage(b);
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                g.InterpolationMode = InterpolationMode.HighQualityBicubic;
                g.Clear(Color.Transparent);//背景透明
                g.TranslateTransform(0, b.Width - sf.Height);//更改原点
                g.RotateTransform(-45);//倾斜角度
                g.DrawString(text, f, whiteBrush, new PointF(0, 0));

                b.Save(filename);
            }
            catch (Exception ex)
            {