将AngularJS范围变量从指令传递给控制器的最简单方法是什么？我见过的所有例子看起来都很复杂，是不是我可以从指令访问控制器，并设置其中一个范围变量？
答案 0 :(得分：149)
于2014/8/25编辑： Here是我分叉的地方。
谢谢@anvarik。
这是JSFiddle。我忘记了分叉的地方。但这是一个很好的例子，显示了=和@
之间的区别<div ng-controller="MyCtrl">
<h2>Parent Scope</h2>
<input ng-model="foo"> <i>// Update to see how parent scope interacts with component scope</i>
<br><br>
<!-- attribute-foo binds to a DOM attribute which is always
a string. That is why we are wrapping it in curly braces so
that it can be interpolated. -->
<my-component attribute-foo="{{foo}}" binding-foo="foo"
isolated-expression-foo="updateFoo(newFoo)" >
<h2>Attribute</h2>
<div>
<strong>get:</strong> {{isolatedAttributeFoo}}
</div>
<div>
<strong>set:</strong> <input ng-model="isolatedAttributeFoo">
<i>// This does not update the parent scope.</i>
</div>
<h2>Binding</h2>
<div>
<strong>get:</strong> {{isolatedBindingFoo}}
</div>
<div>
<strong>set:</strong> <input ng-model="isolatedBindingFoo">
<i>// This does update the parent scope.</i>
</div>
<h2>Expression</h2>
<div>
<input ng-model="isolatedFoo">
<button class="btn" ng-click="isolatedExpressionFoo({newFoo:isolatedFoo})">Submit</button>
<i>// And this calls a function on the parent scope.</i>
</div>
</my-component>
</div>
var myModule = angular.module('myModule', [])
.directive('myComponent', function () {
return {
restrict:'E',
scope:{
/* NOTE: Normally I would set my attributes and bindings
to be the same name but I wanted to delineate between
parent and isolated scope. */
isolatedAttributeFoo:'@attributeFoo',
isolatedBindingFoo:'=bindingFoo',
isolatedExpressionFoo:'&'
}
};
})
.controller('MyCtrl', ['$scope', function ($scope) {
$scope.foo = 'Hello!';
$scope.updateFoo = function (newFoo) {
$scope.foo = newFoo;
}
}]);
答案 1 :(得分：69)
我有很多摆弄这个问题，即使在范围内使用"="定义的变量也无法使其工作。根据您的具体情况，这里有三种解决方案。
我发现在传递给指令时，变量没有按角度进行评估。这意味着您可以访问它并在模板中使用它，但不能在链接或app控制器功能中使用它，除非我们等待它被评估。
如果变量正在更改，或者是通过请求提取，则应使用$observe或$watch：
app.directive('yourDirective', function () {
return {
restrict: 'A',
// NB: no isolated scope!!
link: function (scope, element, attrs) {
// observe changes in attribute - could also be scope.$watch
attrs.$observe('yourDirective', function (value) {
if (value) {
console.log(value);
// pass value to app controller
scope.variable = value;
}
});
},
// the variable is available in directive controller,
// and can be fetched as done in link function
controller: ['$scope', '$element', '$attrs',
function ($scope, $element, $attrs) {
// observe changes in attribute - could also be scope.$watch
$attrs.$observe('yourDirective', function (value) {
if (value) {
console.log(value);
// pass value to app controller
$scope.variable = value;
}
});
}
]
};
})
.controller('MyCtrl', ['$scope', function ($scope) {
// variable passed to app controller
$scope.$watch('variable', function (value) {
if (value) {
console.log(value);
}
});
}]);
这是html（记住括号！）：
<div ng-controller="MyCtrl">
<div your-directive="{{ someObject.someVariable }}"></div>
<!-- use ng-bind in stead of {{ }}, when you can to avoids FOUC -->
<div ng-bind="variable"></div>
</div>
请注意，如果使用$observe函数，则不应将范围中的变量设置为"="。此外，我发现它将对象作为字符串传递，因此如果您传递对象，请使用解决方案＃2 或scope.$watch(attrs.yourDirective, fn)（或＃3 ，如果您的变量没有改变。）
如果您的变量是在例如另一个控制器，但只需等到angular对它进行评估，然后再将其发送到app控制器，我们可以使用$timeout等待$apply运行。此外，我们需要使用$emit将其发送到父作用域app控制器（由于指令中的隔离范围）：
app.directive('yourDirective', ['$timeout', function ($timeout) {
return {
restrict: 'A',
// NB: isolated scope!!
scope: {
yourDirective: '='
},
link: function (scope, element, attrs) {
// wait until after $apply
$timeout(function(){
console.log(scope.yourDirective);
// use scope.$emit to pass it to controller
scope.$emit('notification', scope.yourDirective);
});
},
// the variable is available in directive controller,
// and can be fetched as done in link function
controller: [ '$scope', function ($scope) {
// wait until after $apply
$timeout(function(){
console.log($scope.yourDirective);
// use $scope.$emit to pass it to controller
$scope.$emit('notification', scope.yourDirective);
});
}]
};
}])
.controller('MyCtrl', ['$scope', function ($scope) {
// variable passed to app controller
$scope.$on('notification', function (evt, value) {
console.log(value);
$scope.variable = value;
});
}]);
这是html（没有括号！）：
<div ng-controller="MyCtrl">
<div your-directive="someObject.someVariable"></div>
<!-- use ng-bind in stead of {{ }}, when you can to avoids FOUC -->
<div ng-bind="variable"></div>
</div>
如果变量未更改，并且您需要在指令中对其进行评估，则可以使用$eval函数：
app.directive('yourDirective', function () {
return {
restrict: 'A',
// NB: no isolated scope!!
link: function (scope, element, attrs) {
// executes the expression on the current scope returning the result
// and adds it to the scope
scope.variable = scope.$eval(attrs.yourDirective);
console.log(scope.variable);
},
// the variable is available in directive controller,
// and can be fetched as done in link function
controller: ['$scope', '$element', '$attrs',
function ($scope, $element, $attrs) {
// executes the expression on the current scope returning the result
// and adds it to the scope
scope.variable = scope.$eval($attrs.yourDirective);
console.log($scope.variable);
}
]
};
})
.controller('MyCtrl', ['$scope', function ($scope) {
// variable passed to app controller
$scope.$watch('variable', function (value) {
if (value) {
console.log(value);
}
});
}]);
这是html（记住括号！）：
<div ng-controller="MyCtrl">
<div your-directive="{{ someObject.someVariable }}"></div>
<!-- use ng-bind instead of {{ }}, when you can to avoids FOUC -->
<div ng-bind="variable"></div>
</div>
另外，请看一下这个答案：https://stackoverflow.com/a/12372494/1008519
FOUC参考（无格式内容的闪现）问题：http://deansofer.com/posts/view/14/AngularJs-Tips-and-Tricks-UPDATED