base64 前端显示 data:image/jpg；base64
通常base64是后端服务之间传输时常用的一种方式。即把图片流转成了byte数组，再转成一长串字符串（这就是我们看到的base64格式字符串）。
想要还原成图片，后端通常的做法是将base64的字符串转成byte数组，再将byte数组装到流里写出来，就是图片了。
放在前端显示，主需在这字符串前加上data:image/jpg;base64，jpg换成你图片的后缀。
前端有两种显示方式：1.放CSS里，2.放img标签里。
在css里的写法：
#est_switch {
background: url(data:image/jpg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/4gIoSUNDX1BST0ZJTEUAAQEAAAIYAAAAAAQwAABtbnRyUkdCIFhZWiAAAAAAAAAAAAAAAABhY3NwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAA9tYAAQAAAADTLQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAlkZXNjAAAA8AAAAHRyWFlaAAPsxpwBwiKNIuGxlOz0WhhpoWCMcALb/iyiLCTt8l10f//Z) no-repeat center;
}
在html代码img标签里的写法
<img src="data:image/gif;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/4gIoSUNDX1BST0ZJTEUAAQEAAAIYAAAAAAQwAABtbnRyUkdCIFhZWiAAAAAAAAAAAAAAAABhY3NwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAA9tYAAQAAAADTLQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAlkZXNjAAAA8AAAAHRyWFlaAAPsxpwBwiKNIuGxlOz0WhhpoWCMcALb/iyiLCTt8l10f//Z">还有就是迅雷的地址：
thunder://QUFodHRwOi8vNDYuZHVvdGUub3JnL2R1b3RlX3FxLmV4ZVpa将斜杠后面base64字符串解析，得到：AAhttp://51.duote.org/duote_qq.exeZZ
jpg——data:image/jpg;base64
png——data:image/png;base64
gif——data:image/gif;base64
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文章到此已经结束，以下是紫薯布丁
#est_switch {
background: url(data:image/jpg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/4gIoSUNDX1BST0ZJTEUAAQEAAAIYAAAAAAQwAABtbnRyUkdCIFhZWiAAAAAAAAAAAAAAAABhY3NwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAA9tYAAQAAAADTLQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAlkZXNjAAAA8AAAAHRyWFlaAAPsxpwBwiKNIuGxlOz0WhhpoWCMcALb/iyiLCTt8l10f//Z) no-repeat center;
}
<img src="data:image/gif;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/4gIoSUNDX1BST0ZJTEUAAQEAAAIYAAAAAAQwAABtbnRyUkdCIFhZWiAAAAAAAAAAAAAAAABhY3NwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAA9tYAAQAAAADTLQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAlkZXNjAAAA8AAAAHRyWFlaAAPsxpwBwiKNIuGxlOz0WhhpoWCMcALb/iyiLCTt8l10f//Z">
thunder://QUFodHRwOi8vNDYuZHVvdGUub3JnL2R1b3RlX3FxLmV4ZVpa