Svg转Jpg

Svg转Jpg

需求描述

在C#中将 Svg 转换成 Jpg 图片。

转出来的图片，存在部分文字偏移走开的现象。

通过找到相应位置，调整偏移，解决问题。

关键在于，匹配到 hanging、baseline、rotate 的关键字，修改偏移位置实现。

实现的代码

        public void svgToPng()
        {

            // 导出图件
            int picWidth = 300, picHeight = 200, dpi = 50;


            var svgFile = @".\output\svg.svg";

            var svgLine = File.ReadAllLines(svgFile);

            var svgContent = "";

            var keyHanging = "<text dominant-baseline=\"hanging\"";
            var keyRotate = "rotate(-90)";
            var keyBaseline = "<text dominant-baseline=\"baseline\"";


            for (var i = 0; i < svgLine.Count(); i++)
            {
                var line = svgLine[i];

                if (line.IndexOf(keyHanging) >= 0 )
                {
                    line = processText(line);
                }

                if (line.IndexOf(keyRotate) >= 0)
                {
                    line = processText(line);
                }

                if (line.IndexOf(keyBaseline) >= 0)
                {
                    line = processText(line);
                }


                svgContent += line;
            }









            var svg = SvgDocument.FromSvg<SvgDocument>(svgContent);

            // 导出到 jpg
            var jpgpath = @".\output\jpg2.jpg";


            int nNewWidth = picWidth * 4;
            int nNewHeight = picHeight * 4;

            Bitmap bitmapJpg = svg.Draw(nNewWidth, nNewHeight);
            bitmapJpg.Save(jpgpath, System.Drawing.Imaging.ImageFormat.Jpeg);

        }

        public string processText(string line)
        {
            var keyHanging = "<text dominant-baseline=\"hanging\"";
            var keyRotate = "rotate(-90)";
            var keyBaseline = "<text dominant-baseline=\"baseline\"";

            var pattern = @"translate\(([^\)]+)\)";
            var patternFontSize = @"font-size=""(\d+\.?\d*)""";
            var match = Regex.Matches(line, pattern);

            if (match.Count > 0)
            {
                var result = match[0].Value;
                var m = match[0];
                var groups = m.Groups;

                var beforeText = groups[1].ToString();

                string[] arrItem = beforeText.Split(new[] { ',' });
                var x = Convert.ToDouble(arrItem[0]);
                var y = Convert.ToDouble(arrItem[1]);

                var matchFontSize = Regex.Matches(line, patternFontSize);
                var fontSizeText = matchFontSize[0].Groups[1].Value;
                var fontSize = Convert.ToDouble(fontSizeText);

                if (line.IndexOf(keyRotate) >= 0)
                {
                    if (x < 50)
                    {
                        x += 15;
                    }
                    else
                    {
                        x -= 12;
                    }
                }
                else if (line.IndexOf(keyHanging) >= 0)
                {
                    if (fontSize > 10)
                    {
                        // 加上偏移
                        y += 12;
                    }
                    else
                    {
                        y += 6;
                    }
                }
                else if (line.IndexOf(keyBaseline) >= 0)
                {
                    y -= 10;
                }

                var afterText = x + "," + y;

                line = line.Replace(beforeText, afterText);
            }

            return line;
        }