根据文本框值显示下拉值

Question

我有一个文本框和一个下拉菜单。 文本框的值，我显示的是我从响应中得到的一切。

例如，

下拉值是

$ scope.newPlan = [“ A”，“ I”，“ B”，“ II”，“ C”，“ III”];

我的文本框值是“ A”。 条件是，如果我的文本框值为“ A”，则我只需要在下拉列表中显示“ I”，其余的则不想显示。 如同，

“ A”->“ I”

“ B”->“ II”

“ C”->“ III”

我正在使用angularjs。 如何在下拉菜单中显示此内容。

 It is ahowing all the values. $scope.newPlan = ["A", "I", "B", "II", "C", "III"]; $scope.textboxValue = "A"; if ($scope.existingPlan == "A") { $scope.gpasPlan = $scope.newPlan[1]; } else if ($scope.existingPlan == "B") { $scope.gpasPlan = $scope.newPlan[3]; } else if ($scope.existingPlan == "C") { $scope.gpasPlan = $scope.newPlan[5]; } 

 <select required name="selectnewPlan" ng-model="gpasPlan" ng-options="item for item in newPlan"> <option value="">--Choose New Plan--</option> </select> 

我怎样才能做到这一点..

Answer 1

可以帮助您:)

<!DOCTYPE html>
<html>
<script
    src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
<body>
    <div ng-app="myApp" ng-controller="myCtrl">

        <input type="text" ng-change="changeDropdownValue(existingPlan)"
            ng-model="existingPlan"> <select ng-model="selectedName"
            ng-options="x for x in newPlan">
        </select>
    </div>
    <script>
        var app = angular.module( 'myApp', [] );
        app.controller( 'myCtrl', function ( $scope ) {
            $scope.changeDropdownValue = function ( data ) {
                $scope.newPlan = [
                        "A", "I", "B", "II", "C", "III"
                ];
                if ( $scope.existingPlan == "A" ) {
                    $scope.selectedName = $scope.newPlan[ 1 ];
                    $scope.newPlan = $scope.newPlan[ 1 ];
                    console.log( $scope.newPlan );
                } else if ( $scope.existingPlan == "B" ) {
                    $scope.selectedName = $scope.newPlan[ 3 ];
                    $scope.newPlan = $scope.newPlan[ 3 ];
                } else if ( $scope.existingPlan == "C" ) {
                    $scope.selectedName = $scope.newPlan[ 5 ];
                    $scope.newPlan = $scope.newPlan[ 5 ];
                }
            }

        } );
    </script>
</body>
</html>