XAML 单击时切换 ListViewItem 可见性

Question

我正在尝试根据所选的 ListViewItem 更改项目可见性。基本上，ListView 中的每一列在网格上都有两个项目、一个标签和一个控件（组合框、日期选择器、文本框等）。如果选择 ListViewItem，那么我希望该行中的所有控件都可见，否则标签应该可见。这是在 UserControl 上，而不是在 Window 上，如果这有什么区别的话。

这是我的视图模型

    public class DailyServiceLogsViewModel

{ 

    public int DailyServiceLogID { get; set; }

    public int EmployeePositionID { get; set; }

    public PositionType SelectedEmployeePosition { get; set; }

    public List<PositionType> EmployeePositionList { get; set; }

    public List<EmployeeSelectionListViewModel> EmployeeList { get; set; }

    public EmployeeSelectionListViewModel SelectedEmployee { get; set; }

    public string EmployeeName { get; set; }

    public string PositionDescription { get; set; }

    public DateTime? Date { get; set; }

    public string WorkArea { get; set; }

    public bool SelectedLog { get; set; }

}

代码隐藏

            private DBContext _dbContext= new DBContext();

            public ObservableCollection<DailyServiceLogsViewModel> DailyServiceLogs { get; set; }

            public void OnLoad()

            {

                _dbContext= new DBContext();

                List<EmployeeSelectionListViewModel> employeeList = _dbContext.Employees.Where(emp => emp.Active).Select(employee => new EmployeeSelectionListViewModel { EmployeeID = employee.EmployeeID, EmployeeName = employee.FirstName + " " + employee.LastName }).ToList();

                DailyServiceLogs = new ObservableCollection<DailyServiceLogsViewModel>();

                foreach (var serviceLog in _dbContext.DailyServiceLogs.Where(d => d.PayPeriodID == CurrentPayPeriod.PayPeriodID).OrderBy(d => 

                  }

                  ListViewTest.DataContext = this;

                  ListViewTest.ItemsSource = DailyServiceLogs;

                }

我尝试过使用 DataTriggers，但我对它们不太熟悉

Answer 1

保持 SelectedLog 更新的正确方法是为 ListView 创建一个 ItemContainerStyle 并将其绑定在那里。这是正确的解决方案。您需要使项目视图模型成为实现 INotifyPropertyChanged 的实际视图模型。事实上，更改该属性永远不会影响 UI 中的任何内容，因为 UI 不会收到更改通知。该解决方案如下。但是，如果视图模型并不特别关心它是否被选中，我们可以删除您的 SelectionChanged 处理程序，从项目类中删除 SelectedLog，然后直接绑定到触发器中 ListViewItem 的实际 IsSelected 属性。请注意，您将组合框设置为在选择项目时可见，但在未选择项目时从未隐藏它。我已经解决了这个问题。当我们被选中时，一个控件会隐藏，而当我们未被选中时，另一个控件会隐藏。<Label Content="{Binding EmployeeName}" >&nbsp; &nbsp; <Label.Style>&nbsp; &nbsp; &nbsp; &nbsp; <Style TargetType="{x:Type Label}">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType=ListViewItem}}" Value="True">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Setter Property="Visibility" Value="Hidden"/>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </DataTrigger>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; </Style>&nbsp; &nbsp; </Label.Style></Label><ComboBox Tag="{Binding ElementName=gdEmployee, Path=Tag}" ItemsSource="{Binding EmployeeList}" SelectedValue="{Binding SelectedEmployee.EmployeeID}" DisplayMemberPath="EmployeeName" SelectedValuePath="EmployeeID" FlowDirection="LeftToRight" Margin="15,5" HorizontalAlignment="Stretch" >&nbsp; &nbsp; <ComboBox.Style>&nbsp; &nbsp; &nbsp; &nbsp; <Style TargetType="{x:Type ComboBox}">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType=ListViewItem}}" Value="False">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Setter Property="Visibility" Value="Hidden"/>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </DataTrigger>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; </Style>&nbsp; &nbsp; </ComboBox.Style></ComboBox>您应该学习如何创建和绑定视图模型属性，这就是该解决方案。首先，我们需要创建“viewmodel”实际的视图模型：public class DailyServiceLogsViewModel : ViewModelBase{&nbsp; &nbsp; public int DailyServiceLogID { get; set; }&nbsp; &nbsp; public int EmployeePositionID { get; set; }&nbsp; &nbsp; public PositionType SelectedEmployeePosition { get; set; }&nbsp; &nbsp; public List<PositionType> EmployeePositionList { get; set; }&nbsp; &nbsp; public List<EmployeeSelectionListViewModel> EmployeeList { get; set; }&nbsp; &nbsp; public EmployeeSelectionListViewModel SelectedEmployee { get; set; }&nbsp; &nbsp; public string EmployeeName { get; set; }&nbsp; &nbsp; public string PositionDescription { get; set; }&nbsp; &nbsp; public DateTime? Date { get; set; }&nbsp; &nbsp; public string WorkArea { get; set; }&nbsp; &nbsp; //&nbsp; Only properties like this will notify the UI when they update.&nbsp;&nbsp; &nbsp; private bool _isSelectedLog = false;&nbsp; &nbsp; public bool IsSelectedLog&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; get => _isSelectedLog;&nbsp; &nbsp; &nbsp; &nbsp; set => SetProperty(ref _isSelectedLog, value);&nbsp; &nbsp; }}public class ViewModelBase : INotifyPropertyChanged{&nbsp; &nbsp; public event PropertyChangedEventHandler PropertyChanged;&nbsp; &nbsp; protected virtual void OnPropertyChanged([CallerMemberName] string propName = null) =>&nbsp; &nbsp; &nbsp; &nbsp; PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));&nbsp; &nbsp; public void SetProperty<T>(ref T field, T value, [CallerMemberName] string propName = null)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; if (!Object.Equals(field, value))&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; field = value;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; OnPropertyChanged(propName);&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }}其次，添加一个 ItemContainerStyle，用于在选择项目时设置 IsSelectedLog。您可以删除 SelectionChanged 处理程序。<ListView ItemsSource="{Binding Items}">&nbsp; &nbsp; <ListView.ItemContainerStyle>&nbsp; &nbsp; &nbsp; &nbsp; <Style TargetType="ListViewItem">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Setter Property="IsSelected" Value="{Binding IsSelectedLog}" />&nbsp; &nbsp; &nbsp; &nbsp; </Style>&nbsp; &nbsp; </ListView.ItemContainerStyle>&nbsp; &nbsp; <ListView.View>&nbsp; &nbsp; &nbsp; &nbsp; <GridView>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <GridViewColumn x:Name="clmServiceEmployeeName" Header="Employee" Width="155">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <GridViewColumn.CellTemplate>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <DataTemplate>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Grid Tag="{Binding DailyServiceLogID}">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Label Content="{Binding EmployeeName}" >&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Label.Style>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Style TargetType="{x:Type Label}">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <DataTrigger Binding="{Binding SelectedLog}" Value="True">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Setter Property="Visibility" Value="Hidden"/>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </DataTrigger>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Style>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Label.Style>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Label>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <ComboBox Tag="{Binding ElementName=gdEmployee, Path=Tag}" ItemsSource="{Binding EmployeeList}" SelectedValue="{Binding SelectedEmployee.EmployeeID}" DisplayMemberPath="EmployeeName" SelectedValuePath="EmployeeID" FlowDirection="LeftToRight" Margin="15,5" HorizontalAlignment="Stretch" >&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <ComboBox.Style>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Style TargetType="{x:Type ComboBox}">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <DataTrigger Binding="{Binding SelectedLog}" Value="False">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <Setter Property="Visibility" Value="Hidden"/>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </DataTrigger>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Style.Triggers>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Style>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </ComboBox.Style>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </ComboBox>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </Grid>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </DataTemplate>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </GridViewColumn.CellTemplate>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </GridViewColumn>&nbsp; &nbsp; &nbsp; &nbsp; </GridView>&nbsp; &nbsp; </ListView.View></ListView>