【uniapp】图片合成并导入base64

两张图片合成，宽度固定，高度根据图片自适应

调用

this.mergeImgs(this.imgList).then((res)=>{console.log(res,'图片base64')
})

方法

mergeImgs(imgList) {// 图片合成return new Promise((resolve, reject) => {Promise.all(this.fileDtoList.map(imgList)).then((images) => {const canvas = document.createElement('canvas')const ctx = canvas.getContext('2d')// 确定合成图片的宽度const maxWidth = 1000; // 设置期望的宽度// 计算合成图片的高度const totalHeight = images.reduce((total, img) => {const aspectRatio = img.width / img.height;const scaledHeight = maxWidth / aspectRatio;return total + scaledHeight;}, 0);// 设置 canvas 的大小canvas.width = maxWidth;canvas.height = totalHeight;// 在 canvas 上绘制图片let currentY = 0;images.forEach(image => {const aspectRatio = image.width / image.height;const scaledHeight = maxWidth / aspectRatio;ctx.drawImage(image, 0, currentY, maxWidth, scaledHeight);currentY += scaledHeight;});const base64 = canvas.toDataURL('image/png')resolve(base64)})})},loadImage(url) {return new Promise((resolve, reject) => {const image = new Image();image.onerror = reject;image.src = url;image.crossOrigin = 'Anonymous'image.onload = () => resolve(image);});},