使用BooleanToVisibility转换器隐藏WPF中布局元素的网格中的列

Question

我正尝试使用布尔值将可见性转换器的GRID列的可见性属性绑定到可见性转换器。即使布尔值为假，网格始终可见。请帮我解决这个问题。该代码对于数据网格完全正常，但不适用于网格。这里是代码。

<Window x:Class="MyApp.FirstWindow" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:viewmodel="clr-namespace:MyApp.ViewModel" 
    xmlns:i="clr-namespace:System.Windows.Interactivity; assembly=System.Windows.Interactivity" 
    xmlns:y="clr-namespace:MyApp.Framework.Converter" 
    xmlns:cmd="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.WPF4" 
    DataContext="{Binding MyAppViewModel, Source={StaticResource Locator}}" 
    MinHeight="530" MinWidth="275" Height="530" Width="275" Title="{Binding Title}" > 

<Window.Resources>  
    <y:BoolToVisibilityConverter x:Key="boolToVisibilityConverter" /> 
</Window.Resources> 
    <Grid Margin="5"> 
    <Grid.RowDefinitions> 
     <RowDefinition Height="Auto"/> 
     <RowDefinition/> 
    </Grid.RowDefinitions> 
    <Grid.ColumnDefinitions> 
     <ColumnDefinition/> 
    </Grid.ColumnDefinitions>  
    <Grid Grid.Row="1" Grid.Column="1" Name="gridTest" 
     DataContext="{Binding GridDataContext, Mode=TwoWay}" 
     Visibility="{Binding GridVisibility, Mode= TwoWay, Converter= {StaticResource boolToVisibilityConverter}}" > 
     <Grid.RowDefinitions> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition Height="Auto"/> 
      <RowDefinition/> 
     </Grid.RowDefinitions> 
     <Grid.ColumnDefinitions> 
      <ColumnDefinition Width="Auto"/> 
      <ColumnDefinition/> 
     </Grid.ColumnDefinitions> 

     <Label >Date</Label> 
     <Label Grid.Column="1" Content="{Binding Date}" /> 

     <Label Grid.Row="1">Time</Label> 
     <Label Grid.Row="1" Grid.Column="1" Content="{Binding Time}"/> 
     </Grid> 
</Grid> 

BoolToVisibilityconverter.cs

using System; 
    using System.Collections.Generic; 
    using System.Linq; 
    using System.Text; 
    using System.Windows; 
    using System.Windows.Data; 
    using System.Globalization; 

    namespace MyApp.Framework.Converter 
    { 
    public sealed class BoolToVisibilityConverter : IValueConverter 
    { 

    public object Convert(object value, Type targetType, object  parameter,   System.Globalization.CultureInfo culture) 
    { 
     if (parameter == null) 
     { 
      return ((bool)value == true) ? Visibility.Visible : Visibility.Hidden; 
     } 
     else if (parameter.ToString() == "Inverse") 
     { 
      return ((bool)value == true) ? Visibility.Collapsed : Visibility.Visible; 
     } 
     return false; 
    } 

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 
    { 
     throw new NotImplementedException(); 
    } 

MyAppViewModel.cs

public class MyAppViewModel : ViewModelBase, INotifyPropertyChanged 
{ 

    private bool _isGridVisible = false; 

    private bool _isLabelVisible = false; 
    private MyItem _gridDataContext; 
    public MyItem GridDataContext 
    { 
     get { return _gridDataContext; } 
     set 
     { 
      _gridDataContext = value; 
      OnPropertyChanged("GridDataContext"); 
     } 
    } 

    public bool IsLabelVisible 
    { 
     get 
     { 
      return _isLabelVisible; 
     } 

     set 
     { 
      if (_isLabelVisible == value) 
      { 
       return; 
      } 

      _isLabelVisible = value; 
      OnPropertyChanged("IsLabelVisible"); 
     } 
    } 
    public bool GridVisibility 
    { 
     get 
     { 
      return _isGridVisible; 
     } 

     set 
     { 
      if (_isGridVisible == value) 
      { 
       return; 
      } 

      _isGridVisible = value; 
      OnPropertyChanged("GridVisibility"); 
     } 
    } 


    /// <summary>- 
    /// Initializes a new instance of the AppViewModel class. 
    /// </summary>  
    public AppViewModel() 
    { 
     _gridDataContext = new MyItem(); 
     //other code. 
    } 
    private void UpdateMyItem() 
    { 
     try 
     { 
      bool wasSet = false; 

      if (test== null) 
      { 
       SetVisible(false, "No feature selected."); 
      } 
      else 
      { 
       SetVisible(false, String.Format("No test   
       information selected for my item {0}.",  
       test.name.ToString().PadLeft(5, '0'))); 
      } 
     } 
    private void SetVisible(bool wasSet, string msg) 
    { 

     //under construction 
     if (wasSet) 
     { 
      Dispatcher.CurrentDispatcher.DynamicInvoke(delegate() 
      { 
       GridVisibility = true; 
       IsLabelVisible = false; 

      }); 
     } 
     else if (!wasSet)    
     { 
      Dispatcher.CurrentDispatcher.DynamicInvoke(delegate() 
      { 
       GridVisibility = false; 
       IsLabelVisible = true; 
       LabelContent = msg; 

      }); 
     } 
    } 

} 

}

我还没找到适合我做的任何答案。博客有隐藏/显示Datagrid列的答案，而不是网格布局元素。这可能吗？我的XAML的网格可见性属性是否正常？谢谢你的帮助。

解决方案：MyAppViewModel.cs

 private void SetVisible(bool wasSet, string msg) 
     { 
     if (wasSet) 
     { 
      Dispatcher.CurrentDispatcher.DynamicInvoke(delegate() 
      { 
       GridDataContext.GridVisibility = true; 
       IsLabelVisible = false;     
      }); 
     } 
     else if (!wasSet)    
     { 
      Dispatcher.CurrentDispatcher.DynamicInvoke(delegate() 
      { 
       GridDataContext.GridVisibility = false;   

       IsLabelVisible = true; 
       LabelContent = msg;     
      }); 
     } 
    } 

Answer 1

至于因不同DataContexts规定由@ Ayyappan萨勃拉曼尼亚它。

窗口的上下文是其具有实现GridVisibility属性，但网格的上下文是内MyAppViewModel（typeof运算MyItem）GridDataContext属性的值的MyAppViewModel。

所以你需要指向正确的DataContext结合Visibility

<Grid Grid.Row="1" 
     Grid.Column="1" 
     Name="gridTest" 
     DataContext="{Binding GridDataContext}" 
     Visibility="{Binding DataContext.GridVisibility, 
        Mode=TwoWay, 
        RelativeSource={RelativeSource FindAncestor, AncestorType=Window}, 
        Converter={StaticResource BoolToVisibilityConverter}}"> 

时，或者，如果这不是一个选择，改变MyItem实施，包括给定的属性。

public class MyItem : ViewModelBase 
{ 
    // Current implementation goes here... 

    // GridVisibility implementation 
    private bool _isGridVisible = false; 
    public bool GridVisibility 
    { 
     get { return _isGridVisible; } 
     set 
     { 
      _isGridVisible = value; 
      RaisePropertyChanged(); 
     } 
    } 
}