Question

我正在开发一个Web界面，用于扫描和上传使用AngularJS客户端的文档，以及Dynamsoft的Dynamic Web TWAIN与扫描仪连接。

我正在尝试使用从Dynamsoft的DWObject检索到的可用数据源数组填充<select>，但这些选项不会被填充。我认为问题可能是在页面加载后初始化DWObject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>

的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会填充选项，但select选项不会更新。

$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}]"

更新：添加了所需信息

Answer 1

当第三方代码更新范围数据时，您需要触发Angular摘要周期才能使更改生效，因为angular不知道已经进行了更改。

调用$ digest或$ apply告诉angular更新并触发任何手表。

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

如果您尝试并行执行此操作，还可以将更改包装在angular $ timeout函数中以防止“错误：$ digest已在进行中”。

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

使用AngularJS为选择选项填充一组扫描仪源

1 个答案: