我正在尝试在WPF中创建一个浏览器式的选项卡界面。我已经把它放在一起，它工作了一段时间，但现在所有使选项卡功能的按钮都被禁用了。在实时可视化树中，它显示过度并显示强制设置 IsEnabled = false。父项均未禁用。
我尝试过的几件事。我尝试明确声明所有内容都已启用。这无济于事。我尝试的下一件事是清除所有内容，只使用普通按钮。这奏效了，所以我认为问题出在我的风格中的某个地方。
这行不通
<ItemsControl ItemsSource="{Binding PageViewModels}" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="70,15,0,0">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate >
<Button Background="{x:Null}" Height="24" MinWidth="140" Padding="0,0,0,0" BorderThickness="0" Command="{Binding DataContext.ChangePageCommand, RelativeSource={RelativeSource AncestorType=Window, Mode=FindAncestor} }" CommandParameter="{Binding }">
<Border MinWidth="140" Height="24" >
<Border.Style>
<Style TargetType="Border">
<Style.Triggers>
<DataTrigger Value="True">
<DataTrigger.Binding>
<MultiBinding Converter="{StaticResource IsEqual}">
<Binding Path=".ID"/>
<Binding Path="DataContext.CurrentPageViewModel.ID" RelativeSource="{RelativeSource AncestorType=Window, Mode=FindAncestor}"/>
</MultiBinding>
</DataTrigger.Binding>
<Setter Property="Background" Value="{StaticResource LIGHT_Main_100}"/>
<Setter Property="BorderThickness" Value="0,0,0,3"/>
<Setter Property="BorderBrush" Value="{StaticResource DARK_CYAN_Secondary_100}"/>
</DataTrigger>
</Style.Triggers>
<Setter Property="Background" Value="{StaticResource LIGHT_Main_85}"/>
<Setter Property="BorderThickness" Value="0,0,.5,.5"/>
<Setter Property="BorderBrush" Value="{StaticResource DARK_Faded }"/>
</Style>
</Border.Style>
<DockPanel VerticalAlignment="Stretch" Margin="10,0,0,0">
<Label DockPanel.Dock="Left" Content="{Binding Name}" FontSize="15" Padding="0" Loaded="Label_Loaded" >
<Label.Style>
<Style TargetType="Label">
<Style.Triggers>
<DataTrigger Value="False">
<DataTrigger.Binding>
<MultiBinding Converter="{StaticResource IsEqual}">
<Binding Path=".ID"/>
<Binding Path="DataContext.CurrentPageViewModel.ID" RelativeSource="{RelativeSource AncestorType=Window, Mode=FindAncestor}"/>
</MultiBinding>
</DataTrigger.Binding>
<Setter Property="Foreground" Value="{StaticResource DARK_Faded}"/>
<Setter Property="FontWeight" Value="ExtraLight"/>
</DataTrigger>
</Style.Triggers>
<Setter Property="FontWeight" Value="Bold"/>
</Style>
</Label.Style>
</Label>
<Button DockPanel.Dock="Right" Background="{x:Null}" Content="⤫" Height="24" Width="28" FontSize="15" Padding="0,-6,0,0" HorizontalAlignment="Right" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" BorderThickness="0" Command="{Binding ClosePage }" CommandParameter="{Binding}">
<Button.Style>
<Style TargetType="Button">
<Style.Triggers>
<DataTrigger Value="True">
<DataTrigger.Binding>
<MultiBinding Converter="{StaticResource IsEqual}">
<Binding Path=".ID"/>
<Binding Path="DataContext.CurrentPageViewModel.ID" RelativeSource="{RelativeSource AncestorType=Window, Mode=FindAncestor}"/>
</MultiBinding>
</DataTrigger.Binding>
<Setter Property="Visibility" Value="Visible"/>
</DataTrigger>
</Style.Triggers>
<Setter Property="Visibility" Value="Hidden"/>
</Style>
</Button.Style>
</Button>
</DockPanel>
</Border>
</Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
这确实有效
<ItemsControl ItemsSource="{Binding PageViewModels}" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="70,15,0,0">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate >
<Button Content="Test"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
编辑
这可能是导致我问题的原因。不久前，我从在线示例中复制了此代码，但并不理解它，但它有效。我认为canExecute是错误的，因为我没有发送字符串参数，而是一个对象。感谢您的帮助@Neil
public ICommand ChangePageCommand
{
get
{
if (_changePageCommand == null)
{
_changePageCommand = new RelayCommand(
p => ChangeViewModel((string) p),
p => p is string);
}
return _changePageCommand;
}
}
public class RelayCommand : ICommand
{
#region Fields
readonly Action<object> _execute;
readonly Predicate<object> _canExecute;
#endregion // Fields
#region Constructors
/// <summary>
/// Creates a new command that can always execute.
/// </summary>
/// <param name="execute">The execution logic.</param>
public RelayCommand(Action<object> execute)
: this(execute, null)
{
}
/// <summary>
/// Creates a new command.
/// </summary>
/// <param name="execute">The execution logic.</param>
/// <param name="canExecute">The execution status logic.</param>
public RelayCommand(Action<object> execute, Predicate<object> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
#endregion // Constructors
#region ICommand Members
public bool CanExecute(object parameters)
{
return _canExecute == null ? true : _canExecute(parameters);
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public void Execute(object parameters)
{
_execute(parameters);
}
#endregion // ICommand Members
}
ChangePageCommand 命令的 CanExecute 可能返回 false。要进行检查，只需删除命令绑定并查看按钮是否仍处于禁用状态。
Command="{Binding DataContext.ChangePageCommand, RelativeSource={RelativeSource AncestorType=Window, Mode=FindAncestor} }"