背景水印在正常屏幕下显示，全屏情况下不显示，求解？-灵析社区

const watermark: { set: (str: string) => void } = { set: function (str: string): void { throw new Error("Function not implemented."); } }; let setWatermark = (str: string): string => { const id = '1.23452384164.123412415'; const existingDiv = document.getElementById(id); if (existingDiv !== null) { document.body.removeChild(existingDiv); } const can = document.createElement('canvas'); can.width = 130; can.height = 100; const cans = can.getContext('2d'); if (cans !== null) { cans.rotate(-20 * Math.PI / 180); cans.font = '14px Vedana'; cans.fillStyle = 'rgba(0, 0, 0, 0.50)'; cans.textAlign = 'left'; cans.textBaseline = 'middle'; cans.fillText(str, can.width / 20, can.height); } const div = document.createElement('div'); div.id = id; div.style.pointerEvents = 'none'; div.style.top = '3px'; div.style.left = '0px'; div.style.position = 'fixed'; div.style.zIndex = '100000'; div.style.opacity = '.4'; div.style.width = '100vw'; div.style.height ='100vw'; div.style.background = 'url(' + can.toDataURL('image/png') + ') left top repeat'; document.body.appendChild(div); return id; }; // 该方法只允许调用一次 watermark.set = (str: string): void => { let id = setWatermark(str); setInterval(() => { const existingDiv = document.getElementById(id); if (existingDiv === null) { id = setWatermark(str); } }, 2000); window.onresize = () => { setWatermark(str); }; }; export default watermark;