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							- const formatTime = date => {
 
- 	const year = date.getFullYear()
 
- 	const month = date.getMonth() + 1
 
- 	const day = date.getDate()
 
- 	const hour = date.getHours()
 
- 	const minute = date.getMinutes()
 
- 	const second = date.getSeconds()
 
- 	return [year, month, day].map(formatNumber).join('/') + ' ' + [hour, minute, second].map(formatNumber).join(':')
 
- }
 
- const formatNumber = n => {
 
- 	n = n.toString()
 
- 	return n[1] ? n : '0' + n
 
- }
 
- //4合1 
 
- function convert4to1(res) {
 
- 	let arr = [];
 
- 	for (let i = 0; i < res.length; i++) {
 
- 		if (i % 4 == 0) {
 
- 			let rule = 0.29900 * res[i] + 0.58700 * res[i + 1] + 0.11400 * res[i + 2];
 
- 			if (rule > 200) {
 
- 				res[i] = 0;
 
- 			} else {
 
- 				res[i] = 1;
 
- 			}
 
- 			arr.push(res[i]);
 
- 		}
 
- 	}
 
- 	return arr;
 
- }
 
- //8合1
 
- function convert8to1(arr) {
 
- 	let data = [];
 
- 	for (let k = 0; k < arr.length; k += 8) {
 
- 		let temp = arr[k] * 128 + arr[k + 1] * 64 + arr[k + 2] * 32 + arr[k + 3] * 16 + arr[k + 4] * 8 + arr[k + 5] * 4 +
 
- 			arr[k + 6] * 2 + arr[k + 7] * 1
 
- 		data.push(temp);
 
- 	}
 
- 	return data;
 
- }
 
- //我的图片宽度是240,那么拼接的指令就是[29, 118, 48, 0, 30, 0, 240, 0]
 
- //我的图片宽度是160,那么拼接的指令就是[29, 118, 48, 0, 20, 0, 160, 0]
 
- //补充一点,打印非二维码的图片,宽度一定要是24的倍数,不然打印也会出现乱码
 
- function toArrayBuffer(res) {
 
- 	let arr = convert4to1(res.data);
 
- 	let data = convert8to1(arr);
 
- 	let cmds = [].concat([27, 97, 1], [29, 118, 48, 0, 30, 0, 240, 0], data, [27, 74, 3], [27, 64]);
 
- 	return new Uint8Array(cmds).buffer;
 
- }
 
- function zip_image(res) {
 
- 	let arr = convert4to1(res.data);
 
- 	let data = convert8to1(arr);
 
- 	return data;
 
- }
 
- // export default {
 
- // 	formatTime: formatTime,
 
- // 	toArrayBuffer: toArrayBuffer,
 
- // 	zip_image: zip_image,
 
- // }
 
- module.exports = {
 
- 	formatTime: formatTime,
 
- 	toArrayBuffer: toArrayBuffer,
 
- 	zip_image: zip_image,
 
- }
 
 
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