本人刚开始学习angular，在表单验证这里碰到了一些问题，我的意思是想在blur的时候再让错误提示显示出来，而在focus时不显示错误信息，可是我按照书上的来打，但是不正确，有谁能帮我分析下，谢谢~

    
    
    
    
    
    


    


            

                
Signup
            

            

                Your name
                
                
                

                    Your name is required
                    Your name is required to be at least 3 words
                    Your name can't be longer than 20 words
                
                
                    focused:{{!signup_form.name.$focused}}
                    $dirty:{{signup_form.name.$dirty}}

                    $invalid:{{signup_form.name.$invalid}}

                    required:{{signup_form.name.$error.required}}

                    minlength:{{signup_form.name.$error.minlength}}

                    maxlength:{{signup_form.name.$error.maxlength}}
                
            
        

js

var app = angular.module('app',[]);
app.controller('myCtrl', ['$scope','$timeout', function($scope,$timeout){
    
    
}])
app.directive('ngFocus',function(){
    // var FOCUS_CLASS = "ng-focused";
    return{
        restrict : 'A',
        require : 'ngModel',
        link : function(scope,ele,attrs,ctrl){
            ctrl.$focused = false;
            ele.bind('focus',function(ev){
                // ele.addClass(FOCUS_CLASS);
                scope.$apply(function(){
                    ctrl.$focused = true;
                });
            }).bind('blur',function(ev){
                // ele.removeClass(FOCUS_CLASS);
                scope.$apply(function(){
                    ctrl.$focused = false
                })
            })
        }
    }
})