CronShot 介绍
CronShot 是 Node.js 模块，用来调节，获取，修改和存储 Web 页面截图的。
安装：
npm install cronshot
示例：
var cronshot = require('cronshot'),
middleware = {
'local': require('cronshot-local')
};
// Local File Example
// ------------------
// Takes a screenshot of sports.yahoo.com,
// and saves the screenshot to the local file system
// Save Local File Example
cronshot.startCapturing({
// The webpage URL that you would like to take a screenshot of
'url': 'http://sports.yahoo.com',
// The local path where you would like to save the image
'path': __dirname,
// Only takes one screenshot
'cronPattern': false,
// What middleware functions to use each time a screenshot is taken
'saveMiddleware': [middleware.local]
}, function(err) {
// optional callback function once all screenshots have been taken
if (err) {
console.error(err);
}
});