js判断一个图片地址是否有效

 let  validateImage = (pathImg)  =>{    ////判断图片地址是否有效
    let ImgObj = new Image();
    ImgObj.src = pathImg;
    if(ImgObj.fileSize > 0 || (ImgObj.width > 0 && ImgObj.height > 0)) {
        return true;
    } else {
        return false;
    }
 }

使用 Promise改写为同步

let validateImage = (pathImg) => {
        return new Promise((resolve, reject) => {
            var ImgObj = new Image(); //判断图片地址是否有效
            ImgObj.src = pathImg;
            ImgObj.onload = ( res) => {
                resolve(res);
            }
            ImgObj.onerror = (err) => {
               reject(err)
            }
        })
   }

//调用
validateImage (pathImg).then(()=>{
    //success
}).catch(()=>{
    //fail
})