WPF: ListBox with WrapPanel, vertical scrolling problem

问题

I have a UserControl (XAML below) that has a ListBox that I want to display images inside a WrapPanel, where images are displayed as many as will fit on one row and then wrap onto the next row etc. It works, except when the ListBox grows higher than the available space in the window, I'm not getting a vertical scrollbar, i.e. the contents get clipped. If I set a fixed height on the ListBox, the scrollbar appears and works as expected. How can I get this listbox to grow to the available space and then show a vertical scrollbar? This control is inside StackPanel inside a Grid in the main window. If I wrap the StackPanel inside a ScrollViewer, I get the scrollbar I'm after, but that's not really a good solution if I wanted to add some more controls to the UserControl above the ListBox (e.g. image size "zoom" etc) as I wouldn't want them to scroll with the images.

Thanks!! :)

<UserControl x:Class="GalleryAdmin.UI.GalleryView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ListBox Name="itemListBox" BorderThickness="0" ItemsSource="{Binding}" ScrollViewer.HorizontalScrollBarVisibility="Disabled">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <StackPanel Background="LightGray" Margin="5" >
                    <StackPanel Margin="5">
                        <Image Source="{Binding Path=LocalThumbPath}" Height="100" />
                        <TextBlock Text="{Binding Path=Name}" TextAlignment="Center"></TextBlock>
                    </StackPanel>
                </StackPanel>
            </DataTemplate>
        </ListBox.ItemTemplate>
        <ListBox.ItemsPanel>
            <ItemsPanelTemplate>
                <WrapPanel />
            </ItemsPanelTemplate>
        </ListBox.ItemsPanel>
    </ListBox>

回答1:

I think you better go with override the ItemPanelTemplate:

<Grid>
<ListBox ScrollViewer.HorizontalScrollBarVisibility="Disabled">
    <ListBox.ItemsPanel>
        <ItemsPanelTemplate>
            <WrapPanel IsItemsHost="True" />
        </ItemsPanelTemplate>
    </ListBox.ItemsPanel>
    <ListBoxItem>listbox item 1</ListBoxItem>
    <ListBoxItem>listbox item 2</ListBoxItem>
    <ListBoxItem>listbox item 3</ListBoxItem>
    <ListBoxItem>listbox item 4</ListBoxItem>
    <ListBoxItem>listbox item 5</ListBoxItem>
</ListBox>

回答2:

Well, I finally stumbled upon the solution. I was adding my UserControl to a placeholder panel that looked like this:

            <ScrollViewer Margin="20" >
                <StackPanel Name="contentPanel"></StackPanel>
            </ScrollViewer>

However, when I switched it to a Grid instead, things started to work the way I wanted:

<Grid Name="contentPanel" Margin="20" />

I think it has to do with the StackPanel not taking up all the vertical space by default, like the Grid is doing.

回答3:

All I had to do was set the following, and the problem went away:

<ListBox ScrollViewer.HorizontalScrollBarVisibility="Disabled">

回答4:

I was just looking through several questions about this issue, and although this is an old thread, this one gave me the answer, but just to clarify....

The layout GRID is the answer to most issues like this. To get the proper ListBox/WrapPanel operation to fill the available space, the following code does the trick:

                    <Grid Grid.Row="1" MaxHeight="105">
                        <ListBox ItemTemplate="{DynamicResource StoreGroupTemplate01}" ItemsSource="{Binding StoreGroupHeader}"
                            ScrollViewer.HorizontalScrollBarVisibility="Disabled">
                            <ListBox.ItemsPanel>
                            <ItemsPanelTemplate>
                                    <WrapPanel Orientation="Horizontal"/>
                            </ItemsPanelTemplate>
                            </ListBox.ItemsPanel>
                        </ListBox>
                    </Grid>

I have this in another grid to place the list at the bottom of my screen (ie.. the Grid.Row="1") and you can adjust MaxHeight (or remove it) to control the visible area before the vertical scroll bar will show up.

回答5:

Put your listbox inside of a ScrollViewer and then set the scrollviewer's VerticalScrollBarVisibility property to "Auto"

        <ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Disabled">
    <ListBox Name="itemListBox" BorderThickness="0" ItemsSource="{Binding}" >
    <ListBox.ItemTemplate>
        <DataTemplate>
            <StackPanel Background="LightGray" Margin="5" >
                <StackPanel Margin="5">
                    <Image Source="{Binding Path=LocalThumbPath}" Height="100" />
                    <TextBlock Text="{Binding Path=Name}" TextAlignment="Center"></TextBlock>
                </StackPanel>
            </StackPanel>
        </DataTemplate>
    </ListBox.ItemTemplate>
    <ListBox.ItemsPanel>
        <ItemsPanelTemplate>
            <WrapPanel />
        </ItemsPanelTemplate>
    </ListBox.ItemsPanel>
</ListBox>
</ScrollViewer>

HTH

来源：https://stackoverflow.com/questions/818876/wpf-listbox-with-wrappanel-vertical-scrolling-problem

标签

wpf

listbox

scrollbar

wrappanel