koa-canvas-captcha

适用于Koa框架的canvas绘制的验证码库

Install

npm install koa-canvas-captcha --save

Demo

var captcha = require('koa-canvas-captcha'); 
var path = require("path");
var getCaptcha = function*(){
     //生成验证码 返回text和图buffer
     var item = yield captcha({
         length: 4, 
         fontSize: 30, 
         width: 150, 
         height: 32, 
         color: 'green', // code color,
         background: 'rgb(245,245,245)', // captcha background color
         lineWidth: 0.5, // Interference lines width
         type: 'normal',
         fontPath: path.join(__dirname, './captchaFont.ttf')
     });
     //将验证码答案存在session
     this.session.captcha = item.answer;
    //返回图片
     this.type = 'jpg';
              this.set({
                  'Cache-Control': 'no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0',
                  'Expires': 'Sun, 12 Jan 1986 12:00:00 GMT'
              });
     this.body = item.imageBuffer
 };

Options

• length - (Number ) captcha length
• fontSize - (Number | default: 30 ) captcha font size
• width - (Number | default: 150) image width
• height - (Number | default: 32) height width
• lineWidth - (Number | default: 1) background line width
• background - (String | default: rgb(255,255,255)) background color
• color - (String | default: rgb(0,0,0)) font color
• text - (String) custom captcha text
• fontPath - (String ) the *.ttf file path
• type - (String | default: normal) captcha type
  • normal - random letter and number
  • letter - just letter
  • number - just number
  • arithmetic - random arithmetic

Result

• text - the words on the captcha
• answer - the answer should input
• imageBuffer - imageBuffer