fix: 修复出库单打印预览空白 - iframe 改用 screen 隐藏/print 显示，并等待字体加载

2026-08-16 04:08:20 +08:00
parent 9f416561d6
commit d7cbc706d3
4 changed files with 124 additions and 6 deletions
@@ -0,0 +1,87 @@
+// 视觉验证：打开打印页，等待 iframe 就绪 + 字体加载，截图 iframe 区域
+import { createRequire } from 'module'
+import fs from 'fs'
+
+const PW = 'C:/Users/范先生/AppData/Roaming/npm/node_modules/@playwright/cli/node_modules/playwright-core'
+const require = createRequire(PW + '/package.json')
+const { chromium } = require(PW)
+
+const B = 'http://localhost:5136'
+const token = fs.readFileSync(new URL('_token.txt', import.meta.url), 'utf8').trim()
+const url = `http://localhost:5227/?print=1&template=2&table=RawMaterial_OutStock&row=2&token=${encodeURIComponent(token)}&api=${B}`
+
+const browser = await chromium.launch({ headless: true, channel: 'msedge' })
+const page = await browser.newPage({ viewport: { width: 900, height: 500 } })
+page.on('pageerror', (e) => console.log('[pageerror]', e.message))
+page.on('console', (m) => { if (m.type() === 'error') console.log('[console]', m.text()) })
+await page.goto(url, { waitUntil: 'networkidle', timeout: 30000 })
+
+for (let i = 0; i < 40; i++) {
+  const ok = await page.evaluate(() => {
+    const f = document.querySelector('iframe')
+    return !!(f && f.srcdoc && f.srcdoc.length > 1000)
+  })
+  if (ok) break
+  await new Promise((r) => setTimeout(r, 500))
+}
+
+// 等字体与图片加载
+await page.evaluate(async () => {
+  const f = document.querySelector('iframe')
+  if (f && f.contentDocument) {
+    await f.contentDocument.fonts.ready.catch(() => {})
+    await new Promise((r) => setTimeout(r, 800))
+  }
+})
+
+// 模拟浏览器进入打印预览/打印媒体，验证 iframe 在 @media print 下可见
+await page.emulateMedia({ media: 'print' })
+await page.waitForTimeout(500)
+await page.screenshot({ path: 'print-preview.png' })
+const buf = fs.statSync('print-preview.png')
+console.log('SHOT_SAVED size=' + buf.size)
+
+// 用 canvas 判断内容像素比例（主页面同源 iframe 可访问）
+const stats = await page.evaluate(async () => {
+  const f = document.querySelector('iframe')
+  if (!f || !f.contentDocument) return { err: 'no-iframe' }
+  const d = f.contentDocument
+  const w = 210 * 96 / 25.4 // 793px
+  const h = 99 * 96 / 25.4   // 374px
+  const canvas = document.createElement('canvas')
+  canvas.width = w
+  canvas.height = h
+  const ctx = canvas.getContext('2d')
+  ctx.fillStyle = '#fff'
+  ctx.fillRect(0, 0, w, h)
+  // 将 iframe body 克隆到独立容器渲染后截图（drawWindow 不可用，改用 HTML 转图）
+  const container = document.createElement('div')
+  container.style.position = 'fixed'
+  container.style.left = '0'
+  container.style.top = '0'
+  container.style.zIndex = '99999'
+  container.appendChild(d.body.cloneNode(true))
+  document.body.appendChild(container)
+  // 用 SVG foreignObject 序列化渲染
+  const svg = `<svg xmlns="http://www.w3.org/2000/svg" width="${w}" height="${h}"><foreignObject width="100%" height="100%"><div xmlns="http://www.w3.org/1999/xhtml">${d.body.innerHTML}</div></foreignObject></svg>`
+  const img = new Image()
+  const ok = await new Promise((resolve) => {
+    img.onload = () => resolve(true)
+    img.onerror = () => resolve(false)
+    img.src = 'data:image/svg+xml;charset=utf-8,' + encodeURIComponent(svg)
+  })
+  document.body.removeChild(container)
+  if (!ok) return { err: 'svg-fail' }
+  ctx.drawImage(img, 0, 0, w, h)
+  const data = ctx.getImageData(0, 0, w, h).data
+  let nonWhite = 0
+  for (let i = 0; i < data.length; i += 40) {
+    const r = data[i], g = data[i + 1], b = data[i + 2]
+    if (r < 245 || g < 245 || b < 245) nonWhite++
+  }
+  const total = Math.floor(data.length / 4 / 10)
+  return { nonWhiteRatio: (nonWhite / total).toFixed(4) }
+})
+console.log('PIXEL=' + JSON.stringify(stats))
+await browser.close()
+console.log('DONE')