列表框不显示滚动条答案

【问题标题】：ListBox not showing scrollbar列表框不显示滚动条
【发布时间】：2016-07-25 12:39:20
【问题描述】：

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，但是当元素超出窗口时，必须有滚动条以便我可以看到整个内容。

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，我已经测试了所有可能性：

它在一个网格中。
网格的列定义为 *
我添加了一个滚动查看器

但没有任何效果。

列表项

【问题讨论】：

标签： c# wpf listbox scrollbar

【解决方案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，那么问题在于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。

【讨论】：

【解决方案2】：

查看列定义

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

自动占据您需要的所有空间
试试：

<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>

【讨论】：

【解决方案3】：

我怎么看你有两个选择，你需要“限制”包含网格：

正如其他答案中所建议的那样，设置包含网格宽度或最大宽度，仅当 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>

使用包含ListBoxItems 的RowDefinitions 创建一个“超级网格”（“子网格”），RowDefinitions 将限制子网格（在示例中，不超过 1/3 窗口高度）：

<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>

【讨论】：