blocks|key|4563541|text|只需在控制器中保留一个currentValue变量，您就可以在每次更改时更新该变量。然后，您可以在每次更新它之前将其与新值进行比较。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4563542|使用手表的想法也很好，但我认为简单的变量是最简单、最符合逻辑的解决方案。|4563543|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

<p>Just keep a currentValue variable in your controller that you update on every change. You can then compare that to the new value every time before you update it.'</p>

<p>The idea of using a watch is good as well, but I think a simple variable is the simplest and most logical solution.</p>


blocks|key|4563568|text|您可以使用作用域监视：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4563569|$scope.$watch('user',+function(newValue,+oldValue)+{
++//+access+new+and+old+value+here
++console.log("Your+former+user.name+was+"%2BoldValue.name%2B",+you're+current+user+name+is+"%2BnewValue.name%2B".");
});|code-block|syntax|javascript|4563570|https://docs.angularjs.org/api/ng/type/$rootScope.Scope#$watch|offset|length|4563571|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|1Q|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|T|8|@]|9|@$I|U|J|V|1|W]]|A|$]]|$1|K|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|H]]]]

<p>You can use a scope watch:</p>

<pre><code>$scope.$watch('user', function(newValue, oldValue) {
  // access new and old value here
  console.log("Your former user.name was "+oldValue.name+", you're current user name is "+newValue.name+".");
});
</code></pre>

<p><a href="https://docs.angularjs.org/api/ng/type/$rootScope.Scope#$watch" rel="noreferrer">https://docs.angularjs.org/api/ng/type/$rootScope.Scope#$watch</a></p>


blocks|key|4563594|text|您可以使用手表代替，因为它具有旧的和新的值，但然后您将添加到摘要循环中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4563595|我只需要在控制器中保留第二个变量并设置它。|4563596|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

<p>You could use a watch instead, because that has the old and new value, but then you're adding to the digest cycle.</p>

<p>I'd just keep a second variable in the controller and set that.</p>


blocks|key|4563617|text|使用角度{{+user.id+}}，您可以将旧的user或expression值作为文字字符串添加到ng-change属性中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4563618|<select+ng-change="updateValue(user,+'{{user.id}}')"+
++++++++ng-model="user.id"+ng-options="user.id+as+user.name+for+user+in+users">
</select>|code-block|syntax|javascript|4563619|在ngChange上，updateValue的第一个参数将是新的用户值，第二个参数将是angular最后一次更新选择标记时形成的文字，使用旧的user.id值。|4563620|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>With an angular {{expression}} you can add the old user or user.id value to the ng-change attribute as a literal string:</p>

<pre><code>&lt;select ng-change="updateValue(user, '{{user.id}}')" 
        ng-model="user.id" ng-options="user.id as user.name for user in users"&gt;
&lt;/select&gt;
</code></pre>

<p>On ngChange, the 1st argument to updateValue will be the new user value, the 2nd argument will be the literal that was formed when the select-tag was last updated by angular, with the old user.id value.</p>


blocks|key|57271|text|您可以使用类似ng-change=someMethod({{user.id}})的内容。通过将你的值保存在{{+expression+}}中，它将计算内联表达式，并给出当前值(调用ng-change方法之前的值)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|57272|<select+ng-model="selectedValue"+ng-change="change(selectedValue,+'{{selectedValue}}')">|code-block|syntax|javascript|57273|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>You can use something like ng-change=someMethod({{user.id}}).
By keeping your value in side {{expression}} it will evaluate expression in-line and gives you current value(value before ng-change method is called).</p>

<pre><code>&lt;select ng-model="selectedValue" ng-change="change(selectedValue, '{{selectedValue}}')"&gt;
</code></pre>


blocks|key|57278|text|您还可以使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|57279|<select+ng-change="updateValue(user,+oldValue)"+++++
+++++++ng-init="oldValue=0"
+++++++ng-focus="oldValue=user.id"
+++++++ng-model="user.id"+ng-options="user.id+as+user.name+for+user+in+users">
</select>|code-block|syntax|javascript|57280|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Also you can use </p>

<pre><code>&lt;select ng-change="updateValue(user, oldValue)"     
       ng-init="oldValue=0"
       ng-focus="oldValue=user.id"
       ng-model="user.id" ng-options="user.id as user.name for user in users"&gt;
&lt;/select&gt;
</code></pre>


blocks|key|57303|text|您可以随时执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|57304|...+ng-model="file.PLIK_STATUS"+ng-change="file.PLIK_STATUS+=+setFileStatus(file.PLIK_ID,file.PLIK_STATUS,'{{file.PLIK_STATUS}}')"+...|code-block|syntax|javascript|57305|在控制器中：|57306|$scope.setFileStatus+=+function+(plik_id,+new_status,+old_status)+{
++++var+answer+=+confirm('Czy+na+pewno+zmienić+status+dla+pliku+?');
++++if+(answer)+{
++++++++podasysService.setFileStatus(plik_id,+new_status).then(function+(result)+{
++++++++++++return+new_status;
++++++++});
++++}else{
++++++++return+old_status;
++++}
};|57307|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<p>You can always do:</p>
<pre><code>... ng-model=&quot;file.PLIK_STATUS&quot; ng-change=&quot;file.PLIK_STATUS = setFileStatus(file.PLIK_ID,file.PLIK_STATUS,'{{file.PLIK_STATUS}}')&quot; ...
</code></pre>
<p>and in controller:</p>
<pre><code>$scope.setFileStatus = function (plik_id, new_status, old_status) {
    var answer = confirm('Czy na pewno zmienić status dla pliku ?');
    if (answer) {
        podasysService.setFileStatus(plik_id, new_status).then(function (result) {
            return new_status;
        });
    }else{
        return old_status;
    }
};
</code></pre>


<p>I'm using ng-options to select values from a pulldown. I'd like to be able to compare the old value to the new value. ng-change works well for grabbing the new value of the pull down, but how can I get both the new value and the original value?</p>

<pre><code>&lt;select ng-change="updateValue(user)" ng-model="user.id" ng-options="user.id as user.name for user in users"&gt;&lt;/select&gt; 
</code></pre>

<p>For instance, let's say I wanted the controller to log, "Your former user.name was BILL, your current user name is PHILLIPE."</p>


ng-change get new value and original value

我使用ng-options从下拉菜单中选择值。我希望能够将旧值与新值进行比较。ng-change可以很好地获取下拉列表的新值，但是如何同时获取新值和原始值呢？<select ng-change="updateValue(user)" ng-model="user.id" ng-options="user.id as u...

问ng-change获取新值和原始值
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