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 npm i html2canvas --save import html2canvas from 'html2canvas'; // 想要保存的图片节点 const dom = document.querySelector('img'); // 创建一个新的canvas const Canvas = document.createElement('canvas'); const width = document.body.offsetWidth; // 可见屏幕的宽 const height = document.body.offsetHeight; // 可见屏幕的高 const scale = window.devicePixelRadio; // 设备的devicePixelRadio // 将Canvas画布放大scale倍，然后放在小的屏幕里，解决模糊问题 Canvas.width = width * scale; Canvas.height = height * scale; Canvas.getContext('2d').scale(scale, scale); html2canvas(dom, { canvas: Canvas, scale, useCORS: true, logging: true, width: width + 'px', hegiht: height + 'px', }).then((canvas) => { const context = canvas.getContext('2d'); // 关闭抗锯齿形 context.mozImageSmoothingEnabled = false; context.webkitImageSmoothingEnabled = false; context.msImageSmoothingEnabled = false; context.imageSmoothingEnabled = false; // canvas转化为图片 canvas2Image(canvas, canvas.width, canvas.height); });

 canvas2Image(canvas, canvas.width, canvas.height) { const retCanvas = document.createElement('canvas'); const retCtx = retCanvas.getContext('2d'); retCanvas.width = width; retCanvas.height = height; retCtx.drawImage(canvas, 0, 0, width, height, 0, 0, width, height); const img = document.createElement('img'); img.src = retCanvas.toDataURL('image/jpeg'); // 可以根据需要更改格式 return img; }

 // 封装一个长按方法 longPress(fn) { let timeout = 0; const $this = this; for (let i = 0; i < $this.length; i++) { $this[i].addEventListener('touchstart', () => { timeout = setTimeout(fn, 800); // 长按时间超过800ms，则执行传入的方法 }, false); $this[i].addEventListener('touchend', () => { clearTimeout(timeout); // 长按时间少于800ms，不会执行传入的方法 }, false); } } // 添加生成的图片到body const img = canvas2Image(canvas, canvas.width, canvas.height); document.body.appendChild(img); img.style.cssText = "width:100%;height:100%;position:absolute;top:0;left:0;right:0;bottom:0;opacity:0;";

 $.fn.longPress = function(fn) { let timeout = 0; const $this = this; for (let i = 0; i < $this.length; i++) { $this[i].addEventListener('touchstart', () => { timeout = setTimeout(fn, 800); // 长按时间超过800ms，则执行传入的方法 }, false); $this[i].addEventListener('touchend', () => { clearTimeout(timeout); // 长按时间少于800ms，不会执行传入的方法 }, false); } }; $('img').longPress(() => { saveImg(); });saveImg() { // 想要保存的图片节点 const dom = document.querySelector('img'); // 创建一个新的canvas const Canvas = document.createElement('canvas'); const width = document.body.offsetWidth; // 可见屏幕的宽 const height = document.body.offsetHeight; // 可见屏幕的高 const scale = window.devicePixelRatio; // 设备的devicePixelRatio // 将Canvas画布放大scale倍，然后放在小的屏幕里，解决模糊问题 Canvas.width = width * scale; Canvas.height = height * scale; Canvas.getContext('2d').scale(scale, scale); html2canvas(dom, { canvas: Canvas, scale, useCORS: true, logging: true, width: width + 'px', hegiht: height + 'px', }).then((canvas) => { const context = canvas.getContext('2d'); // 关闭抗锯齿形 context.mozImageSmoothingEnabled = false; context.webkitImageSmoothingEnabled = false; context.msImageSmoothingEnabled = false; context.imageSmoothingEnabled = false; // canvas转化为图片 const img = canvas2Image(canvas, canvas.width, canvas.height); document.body.appendChild(img); img.style.cssText = "width:100%;height:100%;position:absolute;top:0;left:0;right:0;bottom:0;opacity:0;"; } } canvas2Image(canvas, width, height) { const retCanvas = document.createElement('canvas'); const retCtx = retCanvas.getContext('2d'); retCanvas.width = width; retCanvas.height = height; retCtx.drawImage(canvas, 0, 0, width, height, 0, 0, width, height); const img = document.createElement('img'); img.src = retCanvas.toDataURL('image/jpeg'); // 可以根据需要更改格式 return img; }