在第一个下拉列表中执行ng-change后，保留两个下拉值的默认值，以获取第二个下拉列表的选项值

Question

只有医院下拉代码在下拉显示中显示“HOSPITAL 1”，但是当我刷新页面时，病房下拉代码没有显示“WARD 1”。

每次刷新页面时，都会调用医院下拉菜单中的ng-change，并根据所选医院“HOSP1”检索相应的病房，但病房下拉菜单的显示将设置为“请选择病房”而不是“WARD1”。

我试图保留旧的wardCode =='WARD1'，就像我在控制器中为hosp所做的那样，但是在ng-change被触发后值变化无效。

有人知道我在这种情况下是否可以使用角度复制吗？

HTML

<div class="form-group">
<label class="control-label">Hosp</label>
<select ng-model='search.hosp'select-options=" {{hosp}}" select-data=" 
{{search.hospCode}}" ng-change="wardDropdown()" id="hospCode" 
name="hospCode">

    <option value="">Please Select Hosp</option>
    <option ng-repeat="obj in hosp" value="{{obj.VALUE}}">{{obj.LABEL}} 
</option>
</select>
</div>


<div class="form-group">
    <label class="control-label">Ward</label>
    <select ng-model='search.wardCode' select-options="{{wards}}" 
    select-data="{{search.wards}}" id="wardCode" name="wardCode">

        <option value="">Please Select Ward</option>
        <option ng-repeat="obj in wards" value="{{obj.VALUE}}"> 
        {{obj.LABEL}}
        </option>
    </select>
</div>

JS

$scope.search = {}
$scope.search.hosp = 'HOSP1';
$scope.search.wardCode = 'WARD1';

//Start, hosp dropdown list
$scope.hosp = function () {
var url = /searchHosp',
method = methodType.POST,
    functionName = 'searchHosp',
    params = {};

if (data.status == messageStatus.success) {
    $scope.hospitals = data.result;

} else {
    $scope.errorMessage = promptMessage.searchRecordFailure;
}
},
function (error) {
    $scope.errorMessage = promptMessage.exception;
    )
};
$scope.hospitalList();
//End, hosp dropdown 

//Start, ward dropdown 
$scope.wardDropdown = function () {
var url = searchWard,
    method = methodType.POST,
    functionName = 'searchWard',
    params = {};
    params.hosp = $scope.search.hosp;

if (data.status == messageStatus.success) {
    $scope.wards = data.result;
}
} 
else {
$scope.errorMessage = promptMessage.searchRecordFailure;
}

$scope.wardDropdown();

//End, ward dropdown list