Question

Hello其他程序员！

我试图在ListBox中隐藏第一个ListBoxItem，我做错了什么？我疯狂地搜索，不能让它工作。如果有人可以帮助，将是一种乐趣:)。 ......但没有任何东西被隐藏起来:(。

<ListBox x:Name="DemoItemsListBox" Margin="0 16 0 16" SelectedIndex="0" AlternationCount="2147483647"
     ItemsSource="{Binding NavItems}"
     PreviewMouseLeftButtonUp="UIElement_OnPreviewMouseLeftButtonUp"
          Cursor="Hand">

    <ListBox.ItemContainerStyle>
        <Style TargetType="{x:Type ListBoxItem}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding (ItemsControl.AlternationIndex), RelativeSource={RelativeSource FindAncestor, AncestorType=ListBoxItem}}" Value="0">
                    <Setter Property="Visibility" Value="Hidden"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </ListBox.ItemContainerStyle>

    <ListBox.ItemTemplate>
        <DataTemplate DataType="domain:DemoItem">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>

                <materialDesign:PackIcon Kind="{Binding PackIconName}" Height="24" Width="24" Grid.Row="0" Grid.Column="0" />
                <TextBlock Text="{Binding Name}" Margin="32 0 32 0" Grid.Row="0" Grid.Column="1" VerticalAlignment="Center" />
            </Grid>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

修改我得到它部分工作，第一项是不可见的，但我仍然可以点击它并在悬停时看到它。它也消耗空间。

<ListBox x:Name="DemoItemsListBox" Margin="0 16 0 16" SelectedIndex="0" AlternationCount="2147483647"
     ItemsSource="{Binding NavItems}"
     PreviewMouseLeftButtonUp="UIElement_OnPreviewMouseLeftButtonUp"
          Cursor="Hand">

    <ListBox.ItemTemplate>
        <DataTemplate DataType="domain:DemoItem">
            <Grid>
                <Grid.Style>
                    <Style TargetType="{x:Type Grid}">
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding (ItemsControl.AlternationIndex), RelativeSource={RelativeSource FindAncestor, AncestorType=ListBoxItem}}" Value="0">
                                <Setter Property="Visibility" Value="Hidden"/>
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </Grid.Style>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>

                <materialDesign:PackIcon Kind="{Binding PackIconName}" Height="24" Width="24" Grid.Row="0" Grid.Column="0" />
                <TextBlock Text="{Binding Name}" Margin="32 0 32 0" Grid.Row="0" Grid.Column="1" VerticalAlignment="Center" />
            </Grid>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

编辑2 我让它像这样工作。如何使用键来应用Style？我试过像x：Key =＆＃34; MyCoolStyle＆＃34;但我找不到放在哪里。

<Style TargetType="{x:Type ListBoxItem}">
    <Style.Triggers>
        <Trigger Property="ItemsControl.AlternationIndex" Value="0">
            <Setter Property="Visibility" Value="Collapsed"></Setter>
        </Trigger>
    </Style.Triggers>
</Style>

Answer 1

将Visiblity设置为Collaplity未显示且不占用空间。

Answer 2

您可以像这样使用，

    <ListBox x:Name="DemoItemsListBox" Margin="0 16 0 16" SelectedIndex="0" AlternationCount="2147483647"
                     ItemsSource="12345678"
                          Cursor="Hand">
        <ListBox.ItemContainerStyle>
            <Style TargetType="{x:Type ListBoxItem}">
                <Style.Triggers>
                    <Trigger Property="ItemsControl.AlternationIndex" Value="0">
                        <Setter Property="Visibility" Value="Collapsed"/>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </ListBox.ItemContainerStyle>
        <ListBox.ItemTemplate>
            <DataTemplate DataType="domain:DemoItem">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>

                    <TextBlock Text="{Binding}" Margin="32 0 32 0" Grid.Row="0" Grid.Column="1" VerticalAlignment="Center" />
                </Grid>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

为方便起见，我更改了ItemsSource。

如何隐藏ListBox WPF中的第一个项目

2 个答案: