## Read::uid()
### 描述
返回当前已登录用户的uid，若未登录则返回0
### 示例
```
$uid = Read::uid();
if($uid == 0){
return "请先登录哦~";
}
// 业务逻辑
```
## Read::user($uid)
### 描述
返回一个ReadUser实例，便于调用实例的方法
### 示例
获取用户名
```
$username = Read::user($uid)->getUsername();
```
获取Email
```
$email = Read::user($uid)->getEmial();
```
获取头像url
```
$avatar = Read::user($uid)->getAvatar();
```
获取完整的用户信息
```
$info = Read::user($uid)->getInfo();
$username = $info["username"];
$email = $info["email"];
$avatar = $info["avatar"];
```
