Javascript AngularJS-变量必须作为对象属性放置到被触发的$watch
我是AngularJS的新手,我试过:Javascript AngularJS-变量必须作为对象属性放置到被触发的$watch,javascript,angularjs,Javascript,Angularjs,我是AngularJS的新手,我试过: <div ng-controller="ctrl1"> <div ng-controller="ctrl2"> <select ng-model="myvar" ng-options="c for c in vars" ></select> <div>{{myvar}}</div> </div> </div>
<div ng-controller="ctrl1">
<div ng-controller="ctrl2">
<select ng-model="myvar" ng-options="c for c in vars" ></select>
<div>{{myvar}}</div>
</div>
</div>
<script src="js/vendor/angular.min.js"></script>
<script type="text/javascript">
var app = angular.module("myapp", [])
.controller("ctrl1",function($scope, $rootScope) {
$scope.myvar = 1;
$scope.vars = [1, 2, 3];
$scope.$watch("myvar", function(){
console.log("ctrl1 myvar changed");
});
})
.controller("ctrl2",function($scope, $rootScope) {
$scope.$watch("myvar", function(){
console.log("ctrl2 myvar changed");
});
})
.run();
</script>
{{myvar}}
var app=angular.module(“myapp”,[])
.controller(“ctrl1”,函数($scope,$rootScope){
$scope.myvar=1;
$scope.vars=[1,2,3];
$scope.$watch(“myvar”,function()){
console.log(“ctrl1 myvar已更改”);
});
})
.controller(“ctrl2”,函数($scope,$rootScope){
$scope.$watch(“myvar”,function()){
console.log(“ctrl2 myvar已更改”);
});
})
.run();
更改选择值时,不会触发ctrl1中的$watch。但如果我在$scope中使用一个对象并观察其属性,它就会工作:
<div ng-controller="ctrl1">
<div ng-controller="ctrl2">
<select ng-model="settings.myvar" ng-options="c for c in vars" ></select>
<div>{{settings.myvar}}</div>
</div>
</div>
<script src="js/vendor/angular.min.js"></script>
<script type="text/javascript">
var app = angular.module("myapp", [])
.controller("ctrl1",function($scope, $rootScope) {
$scope.settings = {
myvar : 1
};
$scope.vars = [1, 2, 3];
$scope.$watch("settings.myvar", function(){
console.log("ctrl1 myvar changed");
});
})
.controller("ctrl2",function($scope, $rootScope) {
$scope.$watch("settings.myvar", function(){
console.log("ctrl2 myvar changed");
});
})
.run();
</script>
{{settings.myvar}}
var app=angular.module(“myapp”,[])
.controller(“ctrl1”,函数($scope,$rootScope){
$scope.settings={
myvar:1
};
$scope.vars=[1,2,3];
$scope.$watch(“settings.myvar”,function()){
console.log(“ctrl1 myvar已更改”);
});
})
.controller(“ctrl2”,函数($scope,$rootScope){
$scope.$watch(“settings.myvar”,function()){
console.log(“ctrl2 myvar已更改”);
});
})
.run();
这有什么原因吗?我做错了什么,或者我不明白什么?这对我来说非常有效,我需要更多的html来诊断
.controller('MyCtrl2', ['$scope',function($scope) {
$scope.myvar=1;
$scope.vars=[1,2,3];
$scope.$watch('myvar',function(v){
alert(v);
})
}]);
<select ng-options="value for value in vars" ng-model="myvar"></select>
.controller('MyCtrl2',['$scope',函数($scope){
$scope.myvar=1;
$scope.vars=[1,2,3];
$scope.$watch('myvar',函数(v){
警戒(五);
})
}]);
基本上,您需要在父范围中使用对象,而不是原语,然后才能在子范围中进行更新。因此,为什么第二个实现有效,而不是第一个
如果您使用原语,它将在子范围内复制它,因此在子控制器中触发更改时,将永远不会触发父控制器中的watch语句。这表明了这种行为-看一看
HTML
<div ng-app="myapp">
<div ng-controller="ctrl1">
<select ng-model="myvar" ng-options="c for c in vars" ></select>
<div>{{myvar}}</div>
<div ng-controller="ctrl2">
<select ng-model="myvar" ng-options="c for c in vars" ></select>
<div>{{myvar}}</div>
</div>
</div>
</div>
var app = angular.module("myapp", [])
.controller("ctrl1",function($scope, $rootScope) {
$scope.myvar = 1;
$scope.vars = [1, 2, 3];
console.log($scope);
$scope.$watch("myvar", function(){
console.log($scope.myvar);
console.log("ctrl1 myvar changed");
});
})
.controller("ctrl2",function($scope, $rootScope) {
console.log($scope);
console.log($scope.myvar);
console.log($scope);
$scope.$watch("myvar", function(){
console.log($scope.myvar);
console.log($scope.$parent.myvar);
console.log("ctrl2 myvar changed");
});
})
.run();