如何在堆栈面板中固定距主窗口四个角固定距离的WPF数据网格

Question

I have the following wpf layout given to me by my employer. It makes use of multiple nested stack panels. I'm trying to anchor a data grid which is inside a stack panel a fixed distance away from the main window's four corners. And whenever the grid contains data of which some of it is hidden because of the parent window's size, it is supposed to display scroll bars which must disappear if not needed.

---

I set the data grid's and the stack panel's width to Auto so that it fills the width and that makes the horizontal and vertical scroll bars behave as i want them to. BUT the grid doesn't have the required height.

---

But when i try to set the data grid's height property to auto both the horizontal and vertical scroll bars disappear resulting in hidden data. I tried setting the data grids height property to a fixed size and updating it whenever the window is resized but the scroll bars are still hidden how can i fix this?

<UserControl x:Class="WpfApplication1.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="441" d:DesignWidth="300">
    <Grid>
        <StackPanel Margin="0" Name="stackPanel1">
            <ListBox Height="100" Name="listBox1" Width="253" />
            <Button Content="Button" Height="23" Name="button1" Width="256" Click="button1_Click" />
            <StackPanel Name="stackPanel2">
                <StackPanel Height="34" Name="stackPanel3" Width="249" />
                <DataGrid AutoGenerateColumns="False" Name="dataGrid1" Height="282" />
            </StackPanel>
        </StackPanel>
    </Grid>
</UserControl>

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:my="clr-namespace:WpfApplication1" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" x:Class="WpfApplication1.MainWindow"
        Title="MainWindow" Height="502" Width="525" StateChanged="Window_StateChanged">
    <Grid Margin="0">
        <my:UserControl1 x:Name="userControl11" Loaded="userControl11_Loaded" />
    </Grid>
</Window>

Answer 1

When you put items into a vertical StackPanel they like to pretend they have infinite vertical space. Switch over to specifying rows on your Grid , and place your DataGrid in one of those rows. When it's inside a Grid it knows how much space it has available and should show the scrollbars appropriately.

Answer 2

I don't understand all this StackPanel inside StackPanel stuff. You should simply use Grid for your layout:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition/>
    </Grid.RowDefinitions>
    <ListBox Grid.Row="0" Height="100" Name="listBox1" Width="253" />
    <Button Grid.Row="1" Content="Button" Height="23" Name="button1" Width="256" />
    <StackPanel Grid.Row="2" Height="34" Name="stackPanel3" Width="249" />
    <DataGrid Grid.Row="3" AutoGenerateColumns="False" Name="dataGrid1" />
</Grid>

And having an empty StackPanel stackPanel3 as spaceholder seems awkward. Thats what WPF elements have a Margin property for.