列表框不显示滚动条

Question

我有一个列表框，里面有各种元素。它位于具有列定义的网格内，但是当元素超过 window 时，必须有滚动条以便我可以看到全部内容。

而 xaml 是：

<Grid >
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <ListBox x:Name="lbxOptionsTab3" Background="{x:Null}" BorderBrush="Gainsboro" 
                 SelectionChanged="ListBox_SelectionChanged"
                 HorizontalContentAlignment="Stretch" Margin="10" 
                 ScrollViewer.HorizontalScrollBarVisibility="Visible"  
                 ScrollViewer.CanContentScroll="True">
            <ListBox.Effect>
                <DropShadowEffect ShadowDepth="4" Direction="330" Color="Black" Opacity="0.5" BlurRadius="4"/>
            </ListBox.Effect>
        </ListBox>
        <Border x:Name="Border2Tab3" BorderBrush="Gainsboro" 
                Background="{x:Null}"  MinWidth="100" 
                BorderThickness="5" Grid.Column="1" Margin="10,10,10,10">
            ...

我已经阅读了很多这样的解决方案one 简而言之，我已经测试了所有的可能性：

它在一个网格中。
网格的列定义为 *
我添加了滚动查看器

但没有任何效果。

列表项

Answer 1

我会尝试将列表框的宽度或最大宽度设置为某个值，例如 100。如果出现滚动条，则问题是列表框的宽度没有限制。所以他根据需要扩展，因此根本不需要显示它的滚动条。

Answer 2

查看列定义

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

自动占用您需要的所有空间
尝试：

<Grid.ColumnDefinitions>
    <ColumnDefinition Width="*" />
    <ColumnDefinition Width="2*" />
</Grid.ColumnDefinitions>

样本

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*" />
        <ColumnDefinition Width="2*" />
    </Grid.ColumnDefinitions>
    <ListBox Grid.Row="0" Grid.Column="0" 
        ScrollViewer.HorizontalScrollBarVisibility="Visible" >
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
        <ListBoxItem Content="ppp this need to be long longer longest" />
    </ListBox>
    <Border Grid.Row="0" Grid.Column="1" BorderThickness="5" Margin="10" BorderBrush="Red"/>
</Grid>

Answer 3

我怎么看你有两个选择，你都需要 "restrained" 包含网格：

正如其他答案中所建议的那样，设置包含的网格宽度或最大宽度，只有当 ListBoxItems 高度大于网格高度时才会显示滚动条：

<Grid Height="50">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
     </Grid.ColumnDefinitions>
    <ListBox x:Name="lbxOptionsTab3" Background="{x:Null}" BorderBrush="Gainsboro" SelectionChanged="ListBox_SelectionChanged" HorizontalContentAlignment="Stretch" Margin="10" ScrollViewer.HorizontalScrollBarVisibility="Visible" ScrollViewer.CanContentScroll="True">
        <ListBox.Effect>
            <DropShadowEffect ShadowDepth="4" Direction="330" Color="Black" Opacity="0.5" BlurRadius="4"/>
        </ListBox.Effect>
    </ListBox>
    <Border x:Name="Border2Tab3" BorderBrush="Gainsboro" Background="{x:Null}"  MinWidth="100" BorderThickness="5" Grid.Column="1" Margin="10,10,10,10"  >
</Grid>

创建一个 "Super grid" with RowDefinitions 包含 ListBoxItems 包含网格 ("Sub grid")，RowDefinitions 将约束子网格（在例如，不超过 1/3 window 高度）：

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="*" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>

    <Grid Grid.Row="1">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>

       <ListBox x:Name="lbxOptionsTab3"  ScrollViewer.HorizontalScrollBarVisibility="Visible" ScrollViewer.CanContentScroll="True">
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
            <ListBoxItem Content="ppp" />
        </ListBox>
     </Grid>
</Grid>

列表框不显示滚动条

ListBox not showing scrollbar

c#

wpf

listbox

scrollbar