<img>标签传参如何生成图片？

Question

<img src="/GetText.aspx?Text=Post%3A%20200000%20%20E-mail%3A%20mp%40mingpian.sh&FontName=%E6%96%B9%E6%AD%A3%E9%AD%8F%E7%A2%91%E7%AE%80%E4%BD%93&FontSize=11&RGBColor=rgb(223%2C%2053%2C%20142)&Fontweight=Normal&Fontstyle=Normal"/>

Answer 1

php的话，后端使用gd库，c#的话，后端用gdi+都可以动态生成图片的

Answer 2

题主的问题是如何传参，在 JSP 中，一般是通过 el 表达式来完成的。

<img src="/getText?text=${text.text}&amp;font_name=${text.font_name}&amp;font_size=${text.font_size}&amp;rgb_color=${text.rgb_color}&amp;font_weight=${text.font_weight}&amp;font_style=${text.font_style}">

至于 Java 后端的实现可以是这样的 (这里我以 SpringMVC 为例)：

@RequestMapping(value = "getText",method = RequestMethod.GET)

public void getText(

            @RequestParam(value = "text",required = false,defaultValue = "这里输入文字")String text,

            @RequestParam(value = "font_name",required = false,defaultValue = "黑体")String font_name,

            @RequestParam(value = "rgb_color",required = false,defaultValue = "rgb(0,0,0)")String rgb_color,

            @RequestParam(value = "font_style",required = false,defaultValue = "0")String font_style,

            @RequestParam(value = "font_size",required = false,defaultValue = "14")String font_size,

            @RequestParam(value = "font_weight",required = false,defaultValue = "0")String font_weight,

            HttpServletResponse response) throws IOException {

        Graphics tmp = new BufferedImage(300,200,BufferedImage.TYPE_INT_ARGB).getGraphics();

        tmp.setFont(DrawUtil.getFont(font_name, Integer.parseInt(font_size), Integer.parseInt(font_style), Integer.parseInt(font_weight)));

        FontMetrics fm = tmp.getFontMetrics();

        tmp.dispose();

        BufferedImage image = new BufferedImage(fm.stringWidth(text),fm.getHeight(),BufferedImage.TYPE_INT_ARGB);

        Graphics g = image.getGraphics();

        ((Graphics2D)g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        g.setColor(DrawUtil.getColor(rgb_color));

        g.setFont(DrawUtil.getFont(font_name, Integer.parseInt(font_size), Integer.parseInt(font_style), Integer.parseInt(font_weight)));

        g.drawString(text, 0, fm.getHeight()-5);

        g.dispose();

        

        try(ByteArrayOutputStream os = new ByteArrayOutputStream(); 

            OutputStream osm = response.getOutputStream()){

            ImageIO.write(image, "png", os);

            response.setContentType("image/png");

            response.setCharacterEncoding("UTF-8");

            IOUtils.write(os.toByteArray(), osm);

            osm.flush();

        }catch (Exception e) {

            e.printStackTrace();

        }

    }

想要什么样的文字图片，由前端的 JSP 页面传递对应的参数即可。