tp5.1验证码

首先使用composer安装
composer require topthink/think-captcha=2.0.*

页面中使用

<input name="code" lay-verify="required" placeholder="请输入验证码" type="text" class="layui-input">

<br><br>

<img src="{:captcha_src()}" alt="captcha" onclick="this.src=this.src+'?'+Math.random()"/>
PHP中使用
public function login()

{

if (\think\facade\Request::post()){
    $data = input('post.');
    $check = $this->checkCode($data['code']);
    if (!$check){
        $res['status'] = 0;
        return json($res);
    }else{
        $res['status'] = 1;
        return json($res);
    }
}else{
    return $this->fetch();
}

}

public function checkCode($code){

//验证码判断
if(captcha_check($code)){
    return true;
}
else{
    return false;
}

}