javascript Angular JS 复选框 - 模型不默认为 false
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Angular JS checkbox - model doesn't default to false
提问by jonhobbs
I have two checkboxes in my Angular JS form, like this...
我的 Angular JS 表单中有两个复选框，就像这样......
<input id="isBackground" type="checkbox" ng-model="addTemplate.data.isBackground">
<input id="repeats" type="checkbox" ng-model="addTemplate.data.repeats">
If I tick both boxes then write the $scope to the console, both values are set to true, but if I only tick one of them then one appears in the $scope (set to true) and the other one is simply missing. It should be in the $scope and set to 'false' surely?
如果我勾选两个框，然后将 $scope 写入控制台，则两个值都设置为 true，但如果我只勾选其中一个，则 $scope 中出现一个（设置为 true），而另一个则丢失。它应该在 $scope 中并确定设置为“false”吗？
采纳答案by Khanh TO
If a property assigned to ng-modelis undefined, ng-model will automatically create the property after the value is changed for the first time. It means from second time on, you will see both properties.
如果分配的属性ng-model是不确定的，NG-模式将值变更为第一次后自动创建属性。这意味着从第二次开始，您将看到这两个属性。
To avoid this, you could set the default falsefor both properties:
为避免这种情况，您可以false为这两个属性设置默认值：
app.controller('MainCtrl', function($scope) {
$scope.isBackground = false;
$scope.repeats = false;
});
回答by Astronaut
A more flexible solution is to set a ng-init value, this works for dynamic proprieties as well as fixed, something that the accepted solution does not do.
一个更灵活的解决方案是设置一个 ng-init 值，这适用于动态属性和固定属性，这是公认的解决方案所不具备的。
<div class="checkbox">
<label><input type="checkbox" value="" ng-init="formData[field.checkBox]=false" ng-model="formData[field.checkBox]">{{field.name}}</label>
</div>
回答by Satpal
You can use ngTrueValue, and ngFalseValue. I have use 1/0use it accordingly
您可以使用ngTrueValue, 和ngFalseValue。我已经1/0使用它相应地使用它
<input id="isBackground" ng-true-vale="1" ng-false-value="0" type="checkbox" ng-model="addTemplate.data.isBackground">
<input id="repeats" ng-true-vale="1" ng-false-value="0" type="checkbox" ng-model="addTemplate.data.repeats">
From Docs
来自文档
ngTrueValue: The value to which the expression should be set when selected.
ngFalseValue: The value to which the expression should be set when not selected.
ngTrueValue：选择时应将表达式设置为的值。
ngFalseValue：未选择时应将表达式设置为的值。
OR
或者
You can use ngChecked, If the expression is truthy, then special attribute "checked" will be set on the element
您可以使用ngChecked，如果表达式为真，则将在元素上设置特殊属性“checked”
<input id="isBackground" ng-checked="addTemplate.data.isBackground == true" type="checkbox" ng-model="addTemplate.data.isBackground">
<input id="repeats" ng-checked="addTemplate.data.repeats == true" type="checkbox" ng-model="addTemplate.data.repeats">
