字符串转换Json对象

 console.log(this.list[0].mainImg); //打印list里的第一个字符串
 
 {"LocalServicePath":"Images/Main/201907101103296808062244.png","QiniuKey":"/main201907101103296808062244.png"}
 
 const img = JSON.parse(this.list[0].mainImg) //转换Josn格式
 
 console.log(img.LocalServicePath);// 打印出来如下
 
 Images/Main/201907101103296808062244.png