index.wxml
<!--图片宽高大于屏幕宽高--><image style="width: {{imagewidth}}px; height: {{imageheight}}px;" src="{{imageSrc}}" bindload="imageLoad"></image>
index.js
<!--图片宽高大于屏幕宽高-->Page({data: {imageSrc: '/back_pic/00/03/85/1656205138bbe2d.png',//图片链接imagewidth: 0, // 缩放后的宽imageheight: 0, // 缩放后的高},onLoad: function () {},imageLoad: function (e) {var imageSize = this.imageUtil(e)this.setData({imagewidth: imageSize.imageWidth,imageheight: imageSize.imageHeight})},imageUtil: function (e) {var imageSize = {};var originalWidth = e.detail.width; // 图片原始宽var originalHeight = e.detail.height; // 图片原始高var originalScale = originalHeight/originalWidth; //图片高宽比//获取屏幕宽高wx.getSystemInfo({success: function (res) {var windowWidth = res.windowWidth;var windowHeight = res.windowHeight;var windowscale = windowHeight/windowWidth;//屏幕高宽比if (originalScale < windowscale) {// 图片高宽比小于屏幕高宽比//图片缩放后的宽为屏幕宽imageSize.imageWidth = windowWidth;imageSize.imageHeight = (windowWidth * originalHeight) / originalWidth;} else {// 图片高宽比大于屏幕高宽比//图片缩放后的高为屏幕高imageSize.imageHeight = windowHeight;imageSize.imageWidth = (windowHeight * originalWidth) / originalHeight;}}})return imageSize;}})