首先看到“Array to string conversion”这一串我惊呆了，前段时间调试代码的时候还是好好的。

具体产生的原因可能就是用的如下代码

//param接受请求url中的参数
$username = $this->request->param("username","","trim");
$email= $this->request->param("email","","trim");
$password= $this->request->param("password","","trim");
$repassword= $this->request->param("repassword","","trim");


//后来我发现我每次用param接受数据为空，可能就是没有获取到url中的参数
//于是改为如下
$username = input("username","","trim");
$email= $input("email","","trim");
$password= input("password","","trim");
$repassword= input("repassword","","trim");

//咋一看没啥问题，结果忘了input和param第一个参数不一样
//input中第一个参数是key，param第一个参数传的是name

//而且Array to string conversion 的是数组转换成字符串

//所以问题就是在这
//需要改为如下

$username = input("username","");
$email= $input("email","");
$password= input("password","");
$repassword= input("repassword","");


问题就成功解决

 遇到这种问题我也是第一次遇到，所以一开始脑瓜子嗡嗡的