Angular JS - Scope Watch 未更新 [英] Angular JS - Scope Watch Not Updating

问题描述

我可能用错了这个，但我有一个函数来监视一个变量，当从视图中更改该变量时，该函数会运行..但是当同级函数更改该变量时，该监视不会运行.我编码有问题吗?

I might be using this wrong, but I have a function that watches a variable and when that variable is changed from the view, the function runs.. but when a sibling function changes that variable the watch doesn't run. Am I coding something wrong?

scope.$watch (settings.number, function(val){
    alert('test');
})
scope.exampleObj = {
    exampleFunc : function(){
        settings.number += 5;
    }
};

所以当我调用 scope.exampleObj.exampleFunc();不应该调用 scope watch 吗?

so when I call scope.exampleObj.exampleFunc(); shouldn't scope watch get called?

推荐答案

将字符串替换为函数或使用 $watchCollection，如下所示:

Replace string to a function or use $watchCollection, like this:

使用 var:

angular.module('TestApp', [])
    .controller('MainCtrl', function($scope){
        // Object
        var settings = {
            number: 1,
            foobar: 'Hello World'
        };

        $scope.$watch(function(){ return settings.number; }, function(newValue, oldValue){
            console.log('New value detected in settins.number');
        });

        $scope.$watchCollection(function(){ return settings; }, function(newValue, oldValue){
            console.log('New value detected in settings');
        });
    });

使用 $scope:

angular.module('TestApp', [])
    .controller('MainCtrl', function($scope){
        // Object
        $scope.settings = {
            number: 1,
            foobar: 'Hello World'
        };

        $scope.$watch('settings.number', function(newValue, oldValue){
            console.log('New value detected in $scope.settings.number');
        });
    });

示例:http://jsfiddle.net/Chofoteddy/2SNFG/

*注意:$watchCollection 在 AngularJS 1.1.x 及更高版本中可用.如果您需要查看数组中的多个值或对象中的多个属性，它会非常有用.

*Note: $watchCollection that is available in AngularJS version 1.1.x and above. It can be really useful if you need to watch multiple values in a array or multiple properties in a object.

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