MhQuickPrint · คู่มือ

uint32  jsonLength        // 控制文档长度
byte[]  json              // UTF-8 JSON
uint32  blobCount         // 附带二进制页数量
repeat blobCount 次:
  uint64  blobLength      // 该页 PNG 字节数
  byte[]  blob            // 整页 PNG 点阵

{
  "protocol": 1,
  "requestId": "123e4567-e89b-12d3-a456-426614174000",
  "callerId": "LabelTrunk",
  "timestampUtcMs": 1700000000000,
  "command": "system.health"
}

{
  "protocol": 1,
  "requestId": "123e4567-e89b-12d3-a456-426614174000",
  "callerId": "LabelTrunk",
  "timestampUtcMs": 1700000000000,
  "command": "jobs.print",
  "job": {
    "clientJobId": "123e4567-e89b-12d3-a456-426614174001",
    "name": "ENTRY-TEMPLATE",
    "printerId": "stable-printer-id",
    "copies": 1,
    "paper": { "widthMm": 100.0, "heightMm": 60.0 },
    "device": { "dpiX": 203, "dpiY": 203, "capabilityHash": "sha256" },
    "pages": [
      { "widthDots": 799, "heightDots": 480, "format": "png", "blobIndex": 0 }
    ]
  }
}

{
  "protocol": 1,
  "requestId": "123e4567-e89b-12d3-a456-426614174000",
  "ok": false,
  "error": {
    "code": "MQP-3002",
    "message": "页面与二进制数据不匹配"
  }
}

widthDots  = Math.round(widthMm  * dpiX / 25.4)
heightDots = Math.round(heightMm * dpiY / 25.4)

// 例：100 × 60 mm 热敏纸 @203 DPI
// widthDots  = Math.round(100 * 203 / 25.4) = 799
// heightDots = Math.round(60  * 203 / 25.4) = 480

import net from 'node:net';
import { randomUUID } from 'node:crypto';

const PIPE = '\\\\.\\pipe\\LOCAL\\MhQuickPrint.v1';

function frame(json, blobs = []) {
  const control = Buffer.from(JSON.stringify(json));
  const parts = [Buffer.alloc(4), control, Buffer.alloc(4)];
  parts[0].writeUInt32LE(control.length);
  parts[2].writeUInt32LE(blobs.length);
  for (const blob of blobs) {
    const len = Buffer.alloc(8);
    len.writeBigUInt64LE(BigInt(blob.length));
    parts.push(len, blob);
  }
  return Buffer.concat(parts);
}

export function send(command, fields = {}, blobs = []) {
  const request = {
    protocol: 1,
    requestId: randomUUID(),
    callerId: 'my-app',          // 你的系统标识
    timestampUtcMs: Date.now(),
    command,
    ...fields,
  };
  return new Promise((resolve, reject) => {
    const socket = net.createConnection(PIPE);
    const chunks = [];
    let expected = null;
    socket.setTimeout(10000, () => socket.destroy(new Error('响应超时')));
    socket.once('connect', () => socket.write(frame(request, blobs)));
    socket.on('data', chunk => {
      chunks.push(chunk);
      const data = Buffer.concat(chunks);
      if (expected === null && data.length >= 4) expected = data.readUInt32LE(0);
      if (expected !== null && data.length >= expected + 8) {
        socket.end();
        resolve(JSON.parse(data.subarray(4, 4 + expected).toString('utf8')));
      }
    });
    socket.once('error', reject);
  });
}

import { send } from './qp-client.mjs';

// 1) 确认服务在线
await send('system.hello');

// 2) 选择打印机并读取能力（printerId 来自 printers.list）
const caps = await send('printers.capabilities', { printer: { printerId } });
const device = caps.result;   // dpiX / dpiY / capabilityHash / papers[]

// 3) 按目标 DPI 渲染整页 PNG（100 × 60 mm 热敏纸）
const widthDots  = Math.round(100 * device.dpiX / 25.4);
const heightDots = Math.round(60  * device.dpiY / 25.4);
const png = await renderLabelPng(widthDots, heightDots); // 你的排版引擎

// 4) 静默打印（blobIndex 对应 blobs 数组下标）
const result = await send('jobs.print', {
  job: {
    clientJobId: orderNo,       // 业务唯一号：防重复打印
    name: 'ENTRY-TEMPLATE',
    printerId,
    copies: 1,
    paper:  { widthMm: 100, heightMm: 60 },
    device: { dpiX: device.dpiX, dpiY: device.dpiY,
              capabilityHash: device.capabilityHash },
    pages:  [{ widthDots, heightDots, format: 'png', blobIndex: 0 }],
  },
}, [png]);

if (!result.ok) throw new Error(result.error.code + ' ' + result.error.message);