base64转成图片的方法

const express = require('express');
const Buffer = require('Buffer');
const fs = require("fs");
const json = require('./aa.json');

var num = 0;
for(var i in json)
{
var data = json[i];
var path = 'up/'+ (num++) +'.png';//生成的路径+图片的名字
var base64 = data.replace(/^data:image\/\w+;base64,/, ""); //去掉base64前面的头
var dataBuffer = new Buffer(base64, 'base64'); 
fs.writeFile(path,dataBuffer,function(err){
if(err)
{
console.log(err);
}else
{
console.log('写入成功！');
}
});
}