H5压缩图片

# h5压缩图片，本人亲测有效

# 1.在utils/base.js方法里面定义

export function	translate(imgSrc, scale, type , callback) {
		var img = new Image();
		img.src = imgSrc;
		img.onload = function() {
		var that = this;
		var h = that.height; // 默认按比例压缩
		var w = that.width;
		var canvas = document.createElement('canvas');
                var ctx = canvas.getContext('2d');
		var width = document.createAttribute("width");
		width.nodeValue = w/2;
		var height =document.createAttribute("height");
		height.nodeValue = h/2;
		canvas.setAttributeNode(width);
		canvas.setAttributeNode(height);
		ctx.drawImage(that, 0, 0, w/2,h/2);
		var base64 = canvas.toDataURL('image/jpeg', scale);//压缩比例
		canvas = null;
		callback(base64);
					}
				
			}

# 2.在页面引用及使用

 import { translate } from '@/utils/base.js';
 
 translate(res.tempFilePaths[0], 0.7, '', imgUrl => {
        //压缩后返回的图片imgUrl
})