传递引用时的Angularjs数据绑定?
有时,当两个变量引用同一个变量时,它们不会像这样绑定在一起:传递引用时的Angularjs数据绑定?,angularjs,angularjs-bootstrap,Angularjs,Angularjs Bootstrap,有时,当两个变量引用同一个变量时,它们不会像这样绑定在一起: var option = 1; $scope.a = option; $scope.b = option; angular.module('plunker', ['ui.bootstrap']); var ModalDemoCtrl = function($scope, $modal, $log) { $scope.testDataArray = [{ "name": "Doe" }, { "n
var option = 1;
$scope.a = option;
$scope.b = option;
angular.module('plunker', ['ui.bootstrap']);
var ModalDemoCtrl = function($scope, $modal, $log) {
$scope.testDataArray = [{
"name": "Doe"
}, {
"name": "Deer"
}, {
"name": "Female"
}];
$scope.open = function(testData) {
var modalInstance = $modal.open({
templateUrl: 'myModalContent.html',
controller: ModalInstanceCtrl,
resolve: {
data: function() {
return testData;
}
}
});
modalInstance.result.then(function(selectedItem) {
$scope.scopeData = selectedItem;
}, function() {
$log.info('Modal dismissed at: ' + new Date());
});
};
};
// Please note that $modalInstance represents a modal window (instance) dependency.
// It is not the same as the $modal service used above.
var ModalInstanceCtrl = function($scope, $modalInstance, data) {
$scope.modalData1 = data;
$scope.modalData2 = data;
$scope.ok = function() {
$modalInstance.close($scope.modalData);
};
$scope.cancel = function() {
$modalInstance.dismiss('cancel');
};
};
更改$scope.a时,$scope.b不会更改。看到这个了吗
然而,有时它们是绑定在一起的,例如,在我身上发生这样的模态:
var option = 1;
$scope.a = option;
$scope.b = option;
angular.module('plunker', ['ui.bootstrap']);
var ModalDemoCtrl = function($scope, $modal, $log) {
$scope.testDataArray = [{
"name": "Doe"
}, {
"name": "Deer"
}, {
"name": "Female"
}];
$scope.open = function(testData) {
var modalInstance = $modal.open({
templateUrl: 'myModalContent.html',
controller: ModalInstanceCtrl,
resolve: {
data: function() {
return testData;
}
}
});
modalInstance.result.then(function(selectedItem) {
$scope.scopeData = selectedItem;
}, function() {
$log.info('Modal dismissed at: ' + new Date());
});
};
};
// Please note that $modalInstance represents a modal window (instance) dependency.
// It is not the same as the $modal service used above.
var ModalInstanceCtrl = function($scope, $modalInstance, data) {
$scope.modalData1 = data;
$scope.modalData2 = data;
$scope.ok = function() {
$modalInstance.close($scope.modalData);
};
$scope.cancel = function() {
$modalInstance.dismiss('cancel');
};
};
看。
这里的“modalData1”和“modalData2”都是指“数据”。
在这个Plunker的任何模式中,您更改modalData1,然后modalData2随之更改
为什么会这样
谢谢大家! 更新:您应该复制元素,因为javascript是通过引用传递的,所以这两个变量(引用)实际上都指向同一个对象。如果要删除该副作用,必须在指定之前复制对象:
$scope.modalData1 = angular.copy(data);
$scope.modalData2 = angular.copy(data);
原始答复:
在您提供的示例中,modalData2输入随modalData1发生变化,因为它们在ng模型属性中分配了相同的模型:
<div class="modal-body">
modalData1:
<input ng-model="modalData1" />
<br>
modalData2:
<input ng-model="modalData1" />
</div>
modalData1:
modalData2:
当我修复它时,它们是独立的():
modalData1:
modalData2:
然后,当您更新modalData1输入时,另一个不会更改。这是因为angularjs支持双向绑定,这是在您使用angularjs提供的指令ng model时完成的,并且由于您使用相同的ng model值绑定两个输入字段,因此更改一个会反映到另一个 默认情况下,您使用的简单数据类型(如数字1(var option=1:作为整数处理))是复制的另一方面,对象或函数是通过引用传递的,因此它们的内容似乎绑定在一起。在第一种情况下,分配的公共变量是一个整数,这是一种值类型。在第二种情况下,它是一个对象,是引用类型。这意味着,在第一种情况下,您将1的值分配给两个范围变量,因此彼此之间没有链接,而在另一种情况下,您不是复制数据对象,而是将引用分配给原始对象;因此,当对象改变时,引用反映了这一点。我明白了。所以当涉及到对象时,我需要始终使用angular.copy()来剪切绑定?谢谢!那使我很困惑