WPF - SharedSizeGroup +可见性

Question

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
  <Window.Resources>
    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
  </Window.Resources>

  <Grid Grid.IsSharedSizeScope="True">
    <Grid.RowDefinitions>
      <RowDefinition Height="Auto"/>
      <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>

    <Grid.ColumnDefinitions>
      <ColumnDefinition Width="Auto" SharedSizeGroup="FirstColumn"/>
      <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>

    <ToggleButton Name="m_chkTest"
                  Grid.Row="0"
                  Grid.Column="1"                       
                  HorizontalAlignment="Left"
                  Content="Test"
                  Margin="4"/>
    <Grid Grid.Row="1" 
          Grid.ColumnSpan="2"
          Visibility="{Binding IsChecked, ElementName=m_chkTest, Converter={StaticResource ResourceKey=BooleanToVisibilityConverter}}">
      <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
      </Grid.RowDefinitions>

      <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" SharedSizeGroup="FirstColumn"/>
        <ColumnDefinition Width="Auto"/>
        <ColumnDefinition Width="*"/>
      </Grid.ColumnDefinitions>

      <Label Grid.Row="0" Grid.Column="0" Content="Test1"/>
      <Label Grid.Row="0" Grid.Column="1" Content="Test2"/>
      <Label Grid.Row="0" Grid.Column="2" Content="Test3"/>
    </Grid>
  </Grid>
</Window>

当我切换测试切换按钮时，内容从左到中（由于新的可见内容）。我想要的是默认情况下切换按钮是居中的（因为隐藏的内容，不仅因为我改变它的水平对齐。

此图显示了3种可用状态。我通过单击测试切换按钮实现另一种状态。我不想发生的是第一个。

Answer 1

您需要一个与BooleanToVisibility不同的转换器，因为该转换器返回Collapsed是为了可见性而不是Hidden，如下所示：

public class BoolHiddenConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value is bool && ((bool)value))
            return Visibility.Visible;
        return Visibility.Hidden;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value is Visibility && (Visibility)value == Visibility.Visible)
            return true;
        return false;
    }
}