Question

我的$scope中有一个var，我需要减少它，向上滚动时增加，向下滚动时增加。我怎样才能做到这一点？我应该使用js滚动吗？有没有办法不重新发明轮子？

Answer 1

使用javascript <ContentPresenter Content="{TemplateBinding SelectionBoxItem}" > <ContentPresenter.ContentTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding}" /> <Image x:Name="imgArrow" RenderOptions.BitmapScalingMode="HighQuality"> <Image.Style> <Style TargetType="Image"> <Setter Property="Source" Value="{DynamicResource ComboBoxArrowNormalImage}" /> <Style.Triggers> <DataTrigger Binding="{Binding IsDropDownOpen, RelativeSource={RelativeSource AncestorType=ComboBox}}" Value="True"> <Setter Property="Source" Value="{DynamicResource ComboBoxArrowHoverImage}" /> </DataTrigger> </Style.Triggers> </Style> </Image.Style> </Image> </Grid> </DataTemplate> </ContentPresenter.ContentTemplate> </ContentPresenter>功能。

＆＃13;

window.scrollTo

＆＃13;

Answer 2

您的问题不明确，但如果我理解正确，您希望根据滚动方向增加/减少计数器。

你可以采用的方式是点击'scroll'（jQuery）事件，如：

angular.element($window).on('scroll', function(event) {
    // Do something here.
});

最好你可以编写一个自定义指令，然后发出自定义事件，然后你就可以在你的控制器中监听这个事件并对它采取行动。

注意：您也可以去除滚动事件。

P.S。：请始终提供代码段或jsfiddle / codepen，以便其他人可以更好地理解您的问题。

angular.module('app', [])
  .controller('MainController', function($rootScope, $scope) {
    var changeBy = 5;
    $scope.scrollCounter = 0;

    // Tap into custom 'scrollHappened' event.
    $rootScope.$on('scrollHappened', function(event, scrollUpHappened) {

      // If the scroll direction is 'down'.
      if (scrollUpHappened) {
        $scope.scrollCounter += changeBy;
      } else { // Scroll direction is 'up'.
        $scope.scrollCounter -= changeBy;
      }
    });
  })
  .directive('scrollCounter', function($rootScope, $window) {
    return {
      restrict: 'A',
      link: function() {
        var lastScrollPos = 0;

        // Add a scroll event on $window object.
        angular.element($window).on('scroll', function(event) {
        console.log(angular.element(event.target))
          var scrollPos = angular.element(event.target).scrollTop();

          // Emit custom 'scrollHappened' event.
          $rootScope.$emit('scrollHappened', (scrollPos > lastScrollPos));

          // As all this is happening outside of the angular world
          // wrap the update logic inside $apply, so that update will
          // be visible to the angular.
          $rootScope.$apply(function() {
            lastScrollPos = scrollPos;
          });
        });
      }
    }
  })

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.1/angular.min.js"></script>

<div data-ng-app="app" data-ng-controller="MainController">

  <div scroll-counter="" style="height: 400px">
    <span>Current scroll counter = {{ scrollCounter }}</span>
    <br/><br/>
    <span>Current scroll counter = {{ scrollCounter }}</span>
    <br/><br/>
    <span>Current scroll counter = {{ scrollCounter }}</span>
    <br/><br/>
    <span>Current scroll counter = {{ scrollCounter }}</span>
    <br/><br/>
    <span>Current scroll counter = {{ scrollCounter }}</span>
    <br/><br/>
    <span>Current scroll counter = {{ scrollCounter }}</span>
    <br/><br/>
  </div>

</div>

滚动时的角度变化var

2 个答案: