使用 AngularJS 填充 Select 选项的扫描仪源数组

Question

我正在开发一个用于扫描和上传文档的 Web 界面，该界面使用 AngularJS 客户端和 Dynamsoft 的 Dynamic Web TWAIN 与扫描仪进行交互。

我正在尝试使用从 Dynamsoft 的 DWObject 检索到的可用源数组来填充 <select>，但选项没有被填充。我认为问题可能是 DWObject 在页面加载后初始化，但我可能错了。（我是 AngularJS 的新手）。

这是我的代码： HTML

<select ng-options="item.label for item in asyncSources track by item.value" ng-model="source">
    <option value="">Select Option</option>
</select>

JavaScript

function scannerController($scope) {

    // Register OnWebTwainReady event. This event fires as soon as Dynamic Web TWAIN is initialized and ready to be used
    Dynamsoft.WebTwainEnv.RegisterEvent('OnWebTwainReady', $scope.Dynamsoft_OnReady);

    // The DWObject is the object that interfaces with all scanner devices
    var DWObject;
    $scope.source = {
        name: '',
        value: 0
    };
    $scope.asyncSources = [];

    // Load the scanner sources
    $scope.loadSources = function () {
        if (DWObject) {
            var count = DWObject.SourceCount; // Populate how many sources are installed in the system

            for (var i = 0; i < count; i++) {
                arr.push({ label: DWObject.GetSourceNameItems(i), value: i })
            }
            $scope.asyncSources = angular.copy(arr);
        }
    }

// Initialise the Dynamsoft Scanner interface
    $scope.Dynamsoft_OnReady = function () {
        Dynamsoft.WebTwainEnv.Unload();
        Dynamsoft.WebTwainEnv.Load();// load all the resources of Dynamic Web TWAIN

        // Delay the retrieval of the Dynamic Web TWAIN Object until AngularJS had fully loaded the page template.
        setTimeout(function () {
            DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');// Get the Dynamic Web TWAIN object that is embeded in the div with id 'dwtcontrolContainer'
            if (DWObject) {
                // Allow users to scan more than 2
                DWObject.IfAllowLocalCache = true;
                DWObject.SelectionImageBorderColor = 0xff0000;
                $scope.loadSources();
                // Try load settings from cookies first
                getSourceFromCookie();
                if ($scope.initialSettingsLoad) $scope.initializeSettings();
            }
        }, 2000);
    }

asyncSources 填充了选项，但 select 选项未更新。

$scope.asyncSources
[[object Object],[object Object]]
[prototype]: []
length: 2
[0]: {...}
[1]: {...}

JSON.stringify($scope.asyncSources)
"[{\"label\":\"PaperStream IP fi-7160 #2\",\"value\":0},{\"label\":\"HP HD Webcam [Fixed]\",\"value\":1}]"

已更新：添加了请求的信息

Answer 1

当第 3 方代码更新范围数据时，您需要触发 Angular 摘要循环以使更改生效，因为 angular 不知道已进行更改。

调用 $digest 或 $apply 告诉 angular 更新并触发任何监视。

$scope.asyncSources = angular.copy(arr);
$scope.$apply();

您还可以将您的更改包装在 angular $timeout 函数中，以防止 "Error: $digest already in progress" 如果您尝试并行执行此操作。

$timeout(function(){
  $scope.asyncSources = angular.copy(arr);
});

使用 AngularJS 填充 Select 选项的扫描仪源数组

Populate an array of Scanner Sources for Select Options with AngularJS

angularjs

ng-options

dynamic-web-twain