JavaScript前端图片压缩方法封装，支持配置图片压缩大小及压缩质量。复制方法直接可用。

/*** 图片压缩* @param {string} url - 图片地址** @param {object} optoion - 配置项*/function compressImg(url, optoion={  maxWidth:1000, //最大宽度 px  maxHeight: 1000,//最大高度 px  quality: 0.8 //压缩质量 0-1 }) {    return new Promise(function (resolve, reject) {      try {        let img = new Image();        img.src = URL.createObjectURL(image);        // 缩放图片需要的canvas        let canvas = document.createElement(\\\'canvas\\\');        let context = canvas.getContext(\\\'2d\\\');
        // base64地址图片加载完毕后        img.onload = function () {          // 图片原始尺寸          let originWidth = this.width;          let originHeight = this.height;          // 最大尺寸限制          let maxWidth = optoion.maxWidth,            maxHeight = optoion.maxHeight;          // 目标尺寸          let targetWidth = originWidth,            targetHeight = originHeight;          // 图片尺寸超过500x1000的限制          if (originWidth > maxWidth || originHeight > maxHeight) {            if (originWidth / originHeight > maxWidth / maxHeight) {              // 更宽，按照宽度限定尺寸              targetWidth = maxWidth;              targetHeight = Math.round(maxWidth * (originHeight / originWidth));            } else {              targetHeight = maxHeight;              targetWidth = Math.round(maxHeight * (originWidth / originHeight));            }          }          // canvas对图片进行缩放          canvas.width = targetWidth;          canvas.height = targetHeight;          // 清除画布          context.clearRect(0, 0, targetWidth, targetHeight);          // 图片压缩          context.drawImage(img, 0, 0, targetWidth, targetHeight);          // canvas转为blob          canvas.toBlob(function (blob) {            let files = new File([blob], image.name, { type: image.type || \\\'image/png\\\' });            resolve(files);          }, image.type || \\\'image/png\\\', option.quality);        }      } catch (e) {        return reject({          code: 1,          msg: \\\'图片压缩出错了!\\\'        });      }    });}

//上传图片最大宽度500px, 最大高度500px，压缩质量0.8const newImg = await obj.compressImg(imgUrl, {  maxWidth: 500,  maxHeight: 500,  quality: 0.8});