Angularjs

Question

我正在使用 Angularjs。我的问题是当我 select 在我的下拉列表中添加一个新选项时，会出现一个对话框。如果对话框的结果为 false，则 selected 下拉选项必须相同。将分析从其他开发人员那里获得的想法。提前致谢！

参考我下面的代码片段：

<div ng-app="myApp" ng-controller="myCtrl">
  <select ng-model="myDropDown" ng-change="Dialog()">
    <option>a</option>
    <option>b</option>
  </select>
</div>

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.Dialog = function () {
        var dialog = confirm('Continue?');
        if(!dialog) {
         alert("Option must not change");
            /** The problem is the dropdown still select the option. **/
        }
    }
});
</script>

Answer 1

这里有一个你可能不知道的技巧：

ng-change="dialog(myDropDown)"         // pass the NEW value of myDropDown
ng-change="dialog('{{myDropDown}}')"   // pass the OLD value of myDropDown

调用 dialog() 时，您可以将先前选择的选项作为参数传递。

然后，如果对话框被取消，就回滚它。

var app = angular.module('myApp', []);

app.controller('myCtrl', function($scope) {
    $scope.dialog = function(prev) {
        var dialog = confirm('Continue?');
        if(!dialog) {
            $scope.myDropDown = prev;
            alert("Option must not change");
        }
    }
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>

<div ng-app="myApp" ng-controller="myCtrl">
  <select ng-model="myDropDown" ng-change="dialog('{{myDropDown}}')">
    <option>a</option>
    <option>b</option>
  </select>
</div>

Angularjs - 如何在确认对话框为 false 时取消下拉菜单的更改事件？

Angularjs - How to cancel change event on dropdown when the confirm dialog is false?

javascript

html-select

dialog