Javascript 使用angularjs从选择选项组中预选一个选项

HTML:

我希望在切换视图时保持视图的状态。因此，当用户选择一个选项并移动到下一个视图，然后返回到上一个视图时，他先前选择的选项应该被预先选择

简而言之，我想从包含选项组的选择中预先选择一个选项

我们可以预先选择一个选项

HTML:

我们可以预先选择一个选项

HTML:

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那么问题是什么，你试过设置ngModel吗？是的，我试过设置$scope.millity='Some specific value'，但它对我来说不起作用，因为它与普通的无选项选择组不起作用。当然，它不会起作用。您应该使用ngOptions+ngModel值作为对象。请您提供帮助，我如何将ng选项用于包含另一个对象数组的如此复杂的对象数组…那么问题是什么，您是否尝试设置ngModel？是的，我尝试设置$scope.military='Some specific value'，但它对我来说并不像普通的无选项选择组那样有效。当然它不会起作用。你应该使用ngOptions+ngModel值作为对象。你能帮我一下吗，我如何使用ng选项来处理这样一个包含另一个对象数组的复杂对象数组。。。

<select id="military" name="military" ng-model="military" ng-change="militaryChange()" style="color: #000;">
    <optgroup label="{{value.label}}" ng-repeat="(key,value) in militaryObject">
        <option value="{{v.value}}" ng-repeat="(k,v) in value.options">{{v.name}}</option>
    </optgroup>
</select>

$scope.militaryObject = [
        {
            label: "U.S. Air Force",
            options: [
                {"name": "Active Duty", "value": "AF - Active Duty (AD)"},
                {"name": "Selective Reserve", "value": "AF - Selective Reserve (SR)"},
                {"name": "Spouse", "value": "AF - Spouse of AD or SR"},
                {"name": "Veteran", "value": "AF - Veteran"},
                {"name": "Civilian", "value": "AF - Civilian"},
                {"name": "Air National Guard", "value": "AF - Air National Guard"}
            ]
        },{
            label: "U.S. Army",
            options: [
                {"name": "Active Duty", "value": "AR - Active Duty (AD)"},
                {"name": "Selective Reserve", "value": "AR - Selective Reserve (SR)"},
                {"name": "Spouse", "value": "AR - Spouse of AD or SR"},
                {"name": "Veteran", "value": "AR - Veteran"},
                {"name": "Civilian", "value": "AR - Civilian"},
                {"name": "Army National Guard", "value": "Army - Air National Guard"}
            ]
        },{
            label: "U.S. Coast Guard",
            options: [
                {"name": "Active Duty", "value": "CG - Active Duty (AD)"},
                {"name": "Selective Reserve", "value": "CG - Selective Reserve (SR)"},
                {"name": "Spouse", "value": "CG - Spouse of AD or SR"},
                {"name": "Veteran", "value": "CG - Veteran"},
                {"name": "Civilian", "value": "CG - Civilian"}
            ]
        },{
            label: "U.S. Marine Corps",
            options: [
                {"name": "Active Duty", "value": "MC - Active Duty (AD)"},
                {"name": "Selective Reserve", "value": "MC - Selective Reserve (SR)"},
                {"name": "Spouse", "value": "MC - Spouse of AD or SR"},
                {"name": "Veteran", "value": "MC - Veteran"},
                {"name": "Civilian", "value": "MC - Civilian"}
            ]
        },{
            label: "U.S. Navy",
            options: [
                {"name": "Active Duty", "value": "NV - Active Duty (AD)"},
                {"name": "Selective Reserve", "value": "NV - Selective Reserve (SR)"},
                {"name": "Spouse", "value": "NV - Spouse of AD or SR"},
                {"name": "Veteran", "value": "NV - Veteran"},
                {"name": "Civilian", "value": "NV - Civilian"}
            ]
        },{
            label: "U.S. Department of Defense",
            options: [
                {"name": "DoD Civilian", "value": "DoD - Civilian"}
            ]
        }
    ];

<select id="military" name="military" ng-model="military" ng-change="militaryChange()" style="color: #000;">
    <optgroup label="{{value.label}}" ng-repeat="(key,value) in militaryObject">
        <option value="{{v.value}}" ng-repeat="v in value.options">{{v.name}}</option>
    </optgroup>
</select>

$scope.military = 'AF - Civilian';