Update App Config During Runtime In C#

NameValueCollection sAll = ConfigurationManager.AppSettings;

            foreach (string str in sAll.AllKeys)

            {

                if (str == appkey)

                {

                    label2.Text = sAll.Get(str);

                }

            } 

// Get AppSettings section from the Config

            Configuration config = ConfigurationManager.OpenExeConfiguration(this.GetType().Assembly.Location);

            AppSettingsSection App_Section = (AppSettingsSection)config.GetSection("appSettings");

            KeyValueConfigurationCollection app_settings = App_Section.Settings;

            KeyValueConfigurationElement element = app_settings[appkey];

            // Grab Key-Value pair & Make your Change

            if (element != null)

            {

                //Create the object

                if (element.Value != label2.Text)

                {

                    element.Value = label2.Text;

                    app_settings.Remove(appkey);

                    app_settings.Add(element);

                    //save to apply changes

                    config.Save();

                    ConfigurationManager.RefreshSection("appSettings");

                    MessageBox.Show("Succeefully changed the Link.\nPlease exit Application and reopen to change reflection..!");                  

                    this.Close();                   

                }   

            }

            else

            {

                MessageBox.Show("Setting not Modified");

            }

SharePoint online - Multi attachments- inside list

 //change event

  <div class="form-group col-md-6">

  <span id="attach">

      <input id="uploadFileID" type="file" ng-file-model="files" multiple />                                               

      <span class="attach-Text" ng-repeat="file in files">

          <span>{{file.name}}</span><a title='Click to Remove' ng-click="removeFile(file, $index)"> X </a>                                                    

      </span>

  </span>

</div>

--------------------------------Controller

$scope.name = 'UploadAttachements';

$scope.files = [];

$scope.removeFile = function (attachedFile, index) {

    var removedItem = $scope.files.indexOf(attachedFile);

    $scope.files.splice(removedItem, 1);

};       

$scope.saveAttachment = function (ListName,ListItemId) {

    if ($scope.files.length > 0) {

        var numberOfFiles = $scope.files.length;

        angular.forEach($scope.files, function (fileValues, key) {

            getFileBuffer(fileValues._file)

                .then(function (bufferVal) {

                    uploadFileSP(bufferVal, fileValues._file.name, ListName, ListItemId);

                    numberOfFiles--;

                    if (numberOfFiles == 0) {

                        console.log("attachment insert success");

                    }

                });

        });

    }

    else {

        alert('no files');

    }

}

function uploadFileSP(bufferVal, fileName, listName, itemID) {         

      var urlValue = _spPageContextInfo.webAbsoluteUrl + "/_api/web/lists/GetByTitle('" + listName + "')/items(" + itemID + ")/AttachmentFiles/add(FileName='" + fileName + "')";

      $.ajax({

          url: urlValue,

          type: "POST",

          data: bufferVal,

          async: false,

          processData: false,

          headers: {

              "X-RequestDigest": $("#__REQUESTDIGEST").val(),

              "accept": "application/json;odata=verbose",

              "content-type": "application/json; odata=verbose"

          },

          success: fileSuccess,

          error: fileError

      });

      function fileSuccess(data) {

          console.log('File Added Successfully.');

      }

      function fileError(error) {

          console.log(error.statusText + "\n\n" + error.responseText);

      }

  }

  function getFileBuffer(file) {

      var deferred = $.Deferred();

      var reader = new FileReader();

      reader.onloadend = function (e) {

          deferred.resolve(e.target.result);

      }

      reader.onerror = function (e) {

          deferred.reject(e.target.error);

      }

      reader.readAsArrayBuffer(file);

      return deferred.promise();

  }

------------------------- add directive--------------------------

 app.directive('ngFileModel', ['$parse', function ($parse) {

      return {

          restrict: 'A',

          link: function (scope, element, attrs) {

              var model = $parse(attrs.ngFileModel);

              var isMultiple = attrs.multiple;

              var modelSetter = model.assign;

              element.bind('change', function () {

                  var values = [];

                  angular.forEach(element[0].files, function (item) {

                      var value = {

                          // File Name

                          name: item.name,

                          //File Size

                          size: item.size,

                          //File URL to view

                          url: URL.createObjectURL(item),

                          // File Input Value

                          _file: item

                      };

                      values.push(value);

                  });

                  scope.$apply(function () {

                      if (isMultiple) {

                          modelSetter(scope, values);

                      } else {

                          modelSetter(scope, values[0]);

                      }

                  });

              });

          }

      };

  }]);

Find Last 5 Weeks Number in C#

public static int GetIso8601WeekOfYear(DateTime time)

{

    DayOfWeek day = CultureInfo.InvariantCulture.Calendar.GetDayOfWeek(time);

    if (day >= DayOfWeek.Monday && day <= DayOfWeek.Wednesday)

    {

        time = time.AddDays(3);

    }

    return CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(time, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);

}

 int week1 = GetIso8601WeekOfYear(DateTime.Today);

int week2 = GetIso8601WeekOfYear(DateTime.Today.AddDays(-(int)DateTime.Today.DayOfWeek - 6));

int week3 = GetIso8601WeekOfYear(DateTime.Today.AddDays(-(int)DateTime.Today.DayOfWeek - 12));

int week4 = GetIso8601WeekOfYear(DateTime.Today.AddDays(-(int)DateTime.Today.DayOfWeek - 18));

int week5 = GetIso8601WeekOfYear(DateTime.Today.AddDays(-(int)DateTime.Today.DayOfWeek - 21));