Csharp 我如何控制包装板，这样如果我删除了一个项目，订单就不会'；t更改

您应该设置该卡的一个属性，以指示您要显示该特定卡的另一个模板，而不是从源集合中移除该卡.

例如，您可以将IsEmpty属性添加到包含Cardstr和Cardclr属性的类中，然后使用带有DataTrigger的ContentControl来动态更改模板:

<ListView ItemsSource="{Binding TodoItemViewModels}"
    ScrollViewer.VerticalScrollBarVisibility="Disabled"
    Drop="Card_Drop"
    AllowDrop="True"
    DragLeave="Card_DragLeave"
    IsEnabled="{Binding Disable, ElementName=root}"
    Background="Green">

    <ListView.Resources>
        <DataTemplate x:Key="cardTemplate">
            <Border BorderThickness="2"
                 BorderBrush="BlanchedAlmond" 
                 Opacity="1"
                 Background="BlanchedAlmond"
                 Width="25" Height="30"
                 MouseMove="Card_MouseMove"
                 CornerRadius="5"
                 HorizontalAlignment="Stretch"
                 VerticalAlignment="Stretch">

                <TextBlock Text="{Binding Cardstr}"
                     HorizontalAlignment="Stretch"
                     VerticalAlignment="Stretch"
                     Foreground="{Binding Cardclr}"
                     Background="BlanchedAlmond" />
            </Border>
        </DataTemplate>
        <DataTemplate x:Key="emptyTemplate">
            <Border>
                <TextBlock>empty...</TextBlock>
            </Border>
        </DataTemplate>
    </ListView.Resources>

    <ListView.ItemTemplate>
        <DataTemplate>
            <ContentControl Content="{Binding}">
                <ContentControl.Style>
                    <Style TargetType="ContentControl">
                        <Setter Property="ContentTemplate" Value="{StaticResource cardTemplate}" />
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding IsEmpty}" Value="True">
                                <Setter Property="ContentTemplate" Value="{StaticResource emptyTemplate}" />
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </ContentControl.Style>
            </ContentControl>
        </DataTemplate>
    </ListView.ItemTemplate>

    <ListView.ItemsPanel>
        <ItemsPanelTemplate>
            <WrapPanel Margin="0" Orientation="Vertical" />
        </ItemsPanelTemplate>
    </ListView.ItemsPanel>

</ListView>

确保您的类实现了INotifyPropertyChanged接口:

public class Card : INotifyPropertyChanged
{
    ...

    private bool _isEmpty;
    public bool IsEmpty
    {
        get { return _isEmpty; }
        set { _isEmpty = value; NotifyPropertyChanged(); }
    }

    public event PropertyChangedEventHandler PropertyChanged; 
    private void NotifyPropertyChanged(string propertyName = "")
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

然后，您只需设置要"删除"的项的IsEmpty属性.