JavaScript/ AngularJS：只有当我单击两次按钮时才会显示错误消息

Question

我有一个angularJS视图，允许用户上传Excel数据并将其导入SQL服务器表。我添加了数据的客户端验证，但仅当我再次单击“上载/导入”按钮时，才会显示错误消息。我不确定代码中的哪个部分导致了此问题。是否可以寻求帮助以尝试解决此问题？我想我可能需要移动变量赋值的位置，但在哪里？$scope.Message我包括Javascript / angularjs代码和html视图。AngularJS//Parse Excel Data   $scope.ParseExcelDataAndSave = function () {    var file = $scope.SelectedFileForUpload;    if (file) {        var reader = new FileReader();        reader.onload = function (e) {            var filename = file.name;            // pre-process data            var binary = "";            var bytes = new Uint8Array(e.target.result);            var length = bytes.byteLength;            for (var i = 0; i < length; i++) {                binary += String.fromCharCode(bytes[i]);            }            // call 'xlsx' to read the file            var data = e.target.result;            var workbook = XLSX.read(binary, { type: 'binary', cellDates: true, cellStyles: true });            var sheetName = workbook.SheetNames[0];            var excelData = XLSX.utils.sheet_to_row_object_array(workbook.Sheets[sheetName]);            exceljsonObj = excelData;            var errors = [];            var rowCounter = 1;            for (var j = 0; j < exceljsonObj.length; j++) {                var xdata = exceljsonObj[j];                if (xdata['Meeting ID'] === undefined || xdata['MeetingID'] === undefined) {                    errors.push('Row: ' + rowCounter + ' is missing the Meeting ID value.' +                                ' Please, verify that the data you are trying to upload meets the required criteria, ' +                                'and then try to upload your file again.');                }};

Answer 1

$scope摘要问题。分配$scope后调用 $scope.apply（）。消息

if (errors.length > 0) {

            $scope.Message = 'Please, verify that the file you are trying to upload is correctly formatted, \n ' +

                                'and that the data it contains, meets the expected criteria, then click the upload button again. \n Thank you!'

    $scope.$apply();

 }