Question

有没有办法在WPF中隐藏组合框的项目？在我的usercontrol中有一个ListBox，其复选框项绑定到ObservableCollection和带有组合框的数据网格。

<ListBox x:Name="AvailableAttributes" Grid.Row="0" Grid.Column="2" SelectionMode="Single" >
    <ListBox.ItemContainerStyle>
        <Style TargetType="{x:Type ListBoxItem}">
            <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=OneWay}"/>
        </Style>
    </ListBox.ItemContainerStyle>

    <ListBox.ItemTemplate>
        <DataTemplate>
            <CheckBox Content="{Binding Name}" IsChecked="{Binding IsSelected}"/>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

... 

<DataGrid Name="datagrid" AutoGenerateColumns="False" >
    <DataGrid.Columns>
        <DataGridTextColumn Binding="{Binding Name}" />
            <DataGridComboBoxColumn 
                SelectedValueBinding="{Binding CBID}" 
                DisplayMemberPath="Name" 
                SelectedValuePath="ID">

                <DataGridComboBoxColumn.ElementStyle>
                    <Style TargetType="{x:Type ComboBox}">
                        <Setter Property="ItemsSource" 
                            Value="{Binding Path=CBItems, RelativeSource={RelativeSource AncestorType={x:Type UserControl}}}" />
                    </Style>
                </DataGridComboBoxColumn.ElementStyle>
                <DataGridComboBoxColumn.EditingElementStyle>
                    <Style TargetType="{x:Type ComboBox}">
                        <Setter Property="ItemsSource" 
                            Value="{Binding Path=CBItems, RelativeSource={RelativeSource AncestorType={x:Type UserControl}}}" />
                    </Style>
                </DataGridComboBoxColumn.EditingElementStyle>
            </DataGridComboBoxColumn>
        </DataGrid.Columns>
    </DataGrid>

我使用this solution来管理组合框项目，并添加了属性＆＃39; IsSelected＆＃39;

public class GridItem
{
    public string Name { get; set; }
    public int CBID { get; set; }
}

public class CBItem
{
    public int ID { get; set; }
    public string Name { get; set; }
    public bool IsSelected { get; set; }
}

现在我想使用＆＃39; IsSelected＆＃39;隐藏/显示组合框中项目的属性。有人能告诉我怎样才能实现这个目标？

Answer 1

非常简单：只需给组合框项目添加一个带有触发器的样式，该触发器根据ComboBoxItem.Visibility IsSelected ComboBoxItem上DataContext的值设置<Style TargetType="{x:Type ComboBox}" BasedOn="{StaticResource {x:Type ComboBox}}"> <Setter Property="ItemsSource" Value="{Binding Path=CBItems, RelativeSource={RelativeSource AncestorType={x:Type UserControl}}}" /> <Setter Property="ItemContainerStyle"> <Setter.Value> <Style TargetType="ComboBoxItem" BasedOn="{StaticResource {x:Type ComboBoxItem}}"> <Style.Triggers> <DataTrigger Binding="{Binding IsSelected}" Value="False"> <Setter Property="Visibility" Value="Collapsed" /> </DataTrigger> </Style.Triggers> </Style> </Setter.Value> </Setter> </Style>：

IsSelected

如果在网格中加载ComboBox后，您可能会在这些项目中更新CBItem的值，则需要在//this will start at 0.5 and keep it half way (1 second) and then aniate the fade to 1 @keyframes fadein { 0% { opacity: 0.5; } 50% { opacity: 0.5; } 100% { opacity: 1; } } //you can do all sorts like blinking etc @keyframes fadein { 0% { opacity: 0.5; } 30% { opacity: 1; } 50% { opacity: 0.5; } 100% { opacity: 1; } }上implement INotifyPropertyChanged以便UI将反映变化。

Answer 2

如果您想显示特定属性并根据另一个属性值过滤项目，您应该一起使用 ItemTemplate 和 ItemContainerStyle。在此示例中，ItemSource 已设置为 ObservableCollection 类型属性，该属性是另一个组合框 ItemSource

的一部分

  <ComboBox x:Name="combo2" ItemsSource="{Binding SelectedItem.Devices,ElementName=combo1}">
     <ComboBox.ItemTemplate>
        <DataTemplate>
           <TextBlock Text="{Binding Name}"></TextBlock>
        </DataTemplate>
      </ComboBox.ItemTemplate>
      <ComboBox.ItemContainerStyle>
         <Style TargetType="ComboBoxItem">
            <Style.Triggers>
               <DataTrigger Binding="{Binding DeviceId}" Value="125">
                  <Setter Property="Visibility" Value="Collapsed"></Setter>
               </DataTrigger>
            </Style.Triggers>
         </Style>
      </ComboBox.ItemContainerStyle>
 </ComboBox>

如何在WPF中隐藏组合框的项目

2 个答案: