微信小程序图片根据屏幕比例缩放

  // 图片根据屏幕比例缩放
  imageUtil(e) {
     

    let self = this,
        imageSize = {
    },
        originalWidth = e.detail.width,//图片原始宽 
        originalHeight = e.detail.height,//图片原始高 
        originalScale = originalHeight/originalWidth;//图片高宽比 

    let windowWidth = self.data.phoneInfo.windowWidth,
        windowHeight = self.data.phoneInfo.windowHeight,
        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;
  },