## Read::uid()
### 描述
返回當前已登錄用戶的uid，若未登錄則返回0
### 示例
```
$uid = Read::uid();
if($uid == 0){
return "請先登錄哦~";
}
// 業務邏輯
```
## Read::user($uid)
### 描述
返回一個ReadUser實例，便于調用實例的方法
### 示例
獲取用戶名
```
$username = Read::user($uid)->getUsername();
```
獲取Email
```
$email = Read::user($uid)->getEmial();
```
獲取頭像url
```
$avatar = Read::user($uid)->getAvatar();
```
獲取完整的用戶信息
```
$info = Read::user($uid)->getInfo();
$username = $info["username"];
$email = $info["email"];
$avatar = $info["avatar"];
```
