我有一个选择列表，其中的内容是从第一个选择列表中选择的内容动态生成的。我似乎无法找到为什么每次更改第一个选择列表时都会触发这些错误：
Uncaught Error: [$rootScope:infdig] 10 $digest() iterations reached. Aborting!
Watchers fired in the last 5 iterations: [[{"msg":"fn:
regularInterceptedExpression","newVal":42,"oldVal":37},{"msg":"fn: regularInterceptedExpression","newVal":"16","oldVal":"14"}],[{"msg":"fn: regularInterceptedExpression","newVal":47,"oldVal":42},{"msg":"fn: regularInterceptedExpression","newVal":"18","oldVal":"16"}],[{"msg":"fn: regularInterceptedExpression","newVal":52,"oldVal":47},{"msg":"fn: regularInterceptedExpression","newVal":"20","oldVal":"18"}],[{"msg":"fn: regularInterceptedExpression","newVal":57,"oldVal":52},{"msg":"fn: regularInterceptedExpression","newVal":"22","oldVal":"20"}],[{"msg":"fn: regularInterceptedExpression","newVal":62,"oldVal":57},{"msg":"fn: regularInterceptedExpression","newVal":"24","oldVal":"22"}]]
http://errors.angularjs.org/1.4.7/$rootScope/infdig?p0=10&p1=%5B%5B%7B%22ms…Expression%22%2C%22newVal%22%3A%2224%22%2C%22oldVal%22%3A%2222%22%7D%5D%5D
每次更改列表时，每次更改列表时，会激活用于生成第二个列表的“makeOptions”几次。
这两个列表的设置如下：
<select ng-model="selected.level1" ng-options="lvl.name as lvl.name for lvl in level1options"></select>
<select ng-model="selected.level2" ng-options="opt.value as opt.label for opt in makeOptions()"></select>
，控制器是：
app.controller('DemoController', function($scope) {
$scope.level1options = [{ name: "A", value: "A" }, { name: "B", value: "B" }, { name: "C", value: "C" }];
$scope.makeOptionsCallCount = 1;
$scope.selected = {};
$scope.makeOptions = function() {
console.log($scope.makeOptionsCallCount++);
var options = [];
for (var i = 0; i < 5; i++) {
options.push({ label: 'Value = ' + i + $scope.selected.level1, value: i + $scope.selected.level1 });
}
return options;
};
});
这是一个奇怪的例子：
http://plnkr.co/edit/mKv7nMjot5XqBj4mkvhR?p=preview
我出错的任何想法？
更新
我可能已经简化了我遇到麻烦的例子。解决方案变得更加复杂，因为我有一个项目列表，您可以为每个项目选择一组值。我道歉，在问我原来的问题时，我忽略了这个元素。
我创建了一个更准确地反映这一点的新例子：
答案 0 :(得分：1)
当你在视图中使用函数时，它会在每个摘要循环上执行。
此外，还有角度添加观察器来生成此函数，例如，如果您在每次调用时返回新数组 - 您将进入无限循环，因为[] != []
在您的情况下，您还有另一个错误：在视图中调用的内部函数更改变量，该变量也在视图中显示。所以对于这个变量也添加了观察者。
您在函数调用中更改值，观察变量变化，再次运行摘要，运行函数，更改值，查看变量等等...
因此，对于解决方案，首先选择更改的更简单的保存选项。
var app = angular.module('demoApp', [])
app.controller('DemoController', function($scope) {
$scope.level1options = [{ name: "A", value: "A" }, { name: "B", value: "B" }, { name: "C", value: "C" }];
$scope.makeOptionsCallCount = 1;
$scope.selected = {};
$scope.makeOptions = function(lvl) {
$scope.options = [];
console.log(++$scope.makeOptionsCallCount);
for (var i = 0; i < 5; i++) {
$scope.options.push({ label: 'Value = ' + i + lvl, value: i + lvl });
}
};
});<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.7/angular.js"></script>
<div ng-app="demoApp" ng-controller="DemoController">
<div>
<h2>Infinite Digest 2</h2>
<select ng-model="selected.level1" ng-options="lvl.name as lvl.name for lvl in level1options" ng-change="makeOptionsCallCount=0;makeOptions(selected.level1)"></select>
<select ng-model="selected.level2" ng-options="opt.value as opt.label for opt in options"></select>
<br/>
<br/>
<div>Level 1: {{selected.level1}}</div>
<div>Level 2: {{selected.level2}}</div>
<div>makeOptions() Called: {{makeOptionsCallCount}} times</div>
</div>
</div>
<强>更新
在您的评论案例中，您可以利用ng-repeat创建自己的范围并保存到 ng-change 事件创建的列表选项这一事实。
另外，您甚至可以使用您的函数makeOptions。
要ng-change，您可以传递表达式：
ng-change="optionsLvLs = makeOptions(option.level1)"
此处在每个选项的ng-repeat范围内，如果发生这种情况，将会创建不会污染您的选项对象的更改事件{/ 1}}。
optionsLvLs var app = angular.module('demoApp', [])
app.controller('DemoController', function($scope) {
$scope.level1options = [{ name: "A", value: "A" }, { name: "B", value: "B" }, { name: "C", value: "C" }];
$scope.selected = {};
$scope.options = [{ name: "A" }];
$scope.makeOptions = function(level1) {
var options = [];
for (var i = 0; i < 5; i++)
{
options.push({ label: 'Value = ' + i + level1, value: i + level1 });
}
return options;
};
$scope.addQuery = function(idx) {
$scope.options.splice(idx + 1, 0, {});
};
$scope.removeQuery = function (idx) {
$scope.options.splice(idx, 1);
};
});
答案 1 :(得分：0)
进行以下更改时，不需要调用函数来动态创建数据：
$scope.level1options = [{ name: "A", value: "A" }, { name: "B", value: "B" }, { name: "C", value: "C" }];
$scope.level2options = [0,1,2,3,4];
<select ng-model="selected.level1" ng-options="lvl.name as lvl.name for lvl in level1options"></select>
<select ng-model="selected.level2" ng-options="i+selected.level1 as 'Value = '+i+selected.level1 for i in level2options"></select>