可以'；t通过绑定从代码后面更新元素的可见性(WP8)

本文关键字：元素 更新 可见性 WP8 代码 绑定 可以 | 更新日期: 2023-09-27 18:05:01

XAML：

<ListBox x:Name="RegionList" Loaded="RegionList_Loaded" Grid.Row="1" Foreground="Black" Margin="0,0,0,10" SelectionChanged="RegionList_SelectionChanged">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <selectors:RegionDataTemplateSelector Content="{Binding}">
                        <selectors:RegionDataTemplateSelector.ItemTemplateFirstLayer>
                            <DataTemplate>
                                <TextBlock Text="{Binding DisplayedName}" Visibility="{Binding VisibilityOption, Mode=TwoWay}" FontSize="24" Margin="5,5,5,5"></TextBlock>
                            </DataTemplate>
                        </selectors:RegionDataTemplateSelector.ItemTemplateFirstLayer>
                        <selectors:RegionDataTemplateSelector.ItemTemplateSecondLayer>
                            <DataTemplate>
                                <TextBlock Text="{Binding DisplayedName}" Visibility="{Binding VisibilityOption, Mode=TwoWay}" Margin="25,5,5,5" TextWrapping="Wrap" Width="350" FontSize="24"/>
                            </DataTemplate>
                        </selectors:RegionDataTemplateSelector.ItemTemplateSecondLayer>
                        <selectors:RegionDataTemplateSelector.ItemTemplateThirdLayer>
                            <DataTemplate>
                                <TextBlock Text="{Binding DisplayedName}" Visibility="{Binding VisibilityOption, Mode=TwoWay}" Margin="45,5,5,5" TextWrapping="Wrap" Width="350" FontSize="24"/>
                            </DataTemplate>
                        </selectors:RegionDataTemplateSelector.ItemTemplateThirdLayer>
                    </selectors:RegionDataTemplateSelector>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

C#：

private void FilterBtn_Click(object sender, RoutedEventArgs e)
    {
        var allRegions = (RegionList.ItemsSource as ObservableCollection<RegionTree>);
        foreach (var region in allRegions)
        {
            if (region.DisplayedName.IndexOf(RegionFilter.Text) >= 0)
            {
                region.VisibilityOption = Visibility.Visible;
            }
            else
            {
                region.VisibilityOption = Visibility.Collapsed;
            }
        }
        RegionList.ItemsSource = allRegions;
    }

当我的列表第一次加载时，所有项目都具有VisibilityOption=Visibility.Visible。当我按下按钮时，其中一些项目从那时起具有Visibility Option=Visiility.Collapsed。但我仍然可以在UI中看到它们。出了什么问题？

编辑：

区域树：

public class RegionTree : BindableBase
{
    public bool IsFirstLayer { get; set; }
    public bool IsSecondLayer { get; set; }
    public bool IsThirdLayer { get; set; }
    public Visibility VisibilityOption { get; set; }
    public string Name;
    public string Code;
    public string RUName;
    public string SWNE;
    public string DisplayedName
    {
        get
        {
            if (Thread.CurrentThread.CurrentUICulture.ToString() == "ru-RU" && RUName != null)
            {
                return RUName;
            }
            else { return Name; }
        }
    }
}

可以'；t通过绑定从代码后面更新元素的可见性(WP8)

属性更改时，您必须引发PropertyChanged事件，否则绑定将不会更新。您的BindingBase类实现了INotifyPropertyChanged，您可以/应该将其用于视图的通知

(http://msdn.microsoft.com/de-de/library/vstudio/system.componentmodel.inotifypropertychanged)

你的房产应该是这样的：

public Visibility VisibilityOption
{
  get { return _visibilityOption; }
  set
  {
    if (_visibilityOption != value)
    {
      _visibilityOption = value;
      OnPropertyChanged("VisibilityOption");
    }
  }
}

public Visibility VisibilityOption { get; set; }

这不是添加属性的正确方式，必须使用OnPropertyChanged("VisibilityOption")才能更新set中的UI。只需修改该属性即可。

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