效果展示：

代码 实现：

后台：

use Validator;

public function login()  
    {  
        if($input = Input::all()){  
            //验证提交的数据  
            $rules = [  
                'user_name'=>'required|between:4,20',  
                'user_pwd'=>'required|between:6,20',  
                'code'=>'required|between:4,4'  
            ];  
            $message = [  
                'user_name.required'=>'账号不能为空！',  
                'user_name.between'=>'账号必须在6-20位之间！',  
                'user_pwd.required'=>'密码不能为空！',  
                'user_pwd.between'=>'密码必须在6-20位之间！',  
                'code.required'=>'验证码不能为空！',  
                'code.between'=>'验证码必须为4位！',  
            ];  
            $validator = Validator::make($input,$rules,$message);  
            //表单验证  
            if($validator->passes()){  
            //验证验证码  
            if($_SESSION['code']!=strtoupper($input['code'])){  
                return back()->with('msg','验证码错误！');  
            }  
            //用户验证  
            $user = DB::table('user')->select  
  
('user_id','user_encrypt','user_pwd')->where('user_name',$input['user_name'])-  
  
>first();  
            if(!$user){  
                return back()->with('msg','用户不存在！');  
            }else{  
                if(md5(md5($input['user_pwd']).$user->user_encrypt)!=$user-  
  
>user_pwd){  
                    return back()->with('msg','密码错误！');  
                }  
                session(['user_id'=>$user->user_id]);  
                return redirect('index');  
               }  
            }else{  
                return back()->withErrors($validator);  
            }  
        }else{  
            return view('admin.login');  
        }  
  
    }  

前台：

class="middle-box text-center loginscreen  animated fadeInDown">  
        
  
            
  
  
                
class="logo-name">h
  
  
            
  
            
欢迎使用 hAdmin
  
              
            
class="m-t" role="form" action="{{URL('/login')}}" method="post">  
               @if(count($errors)>0)  
                            @if(is_object($errors))  
                                @foreach($errors->all() as $error)  
                                
{{$error}}
  
                                @endforeach  
                            @else  
                            
{{$errors}}
  
                        @endif  
                    @endif  
                    @if(session('msg'))  
                        
{{session('msg')}}
  
                    @endif  
                
class="form-group">  
                    class="form-control" placeholder="用户名" required="" name="email">  
                  
                
  
                
class="form-group">  
                    class="form-control" placeholder="密码" required="" name="pwd">  
                
  
                class="btn btn-primary block full-width m-b">登 录  
  
  
                
class="text-muted text-center"> 忘记密码了？ | 注册一个新账号  
                
  
  
            
  
        
  
    
  

$validator->fails()  验证都符合规则返回false 不符合规则返回true

注：转自小白丶程序猿的博客