相关疑难解决方法(0)

这是我的XAML代码:

<Window x:Class="CarFinder.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Search for cars in TuMomo" Height="480" Width="600">
    <DockPanel Margin="8">
        <Border CornerRadius="6"
                BorderBrush="Gray"
                Background="LightGray"
                BorderThickness="2"
                Padding="8">
            <StackPanel Orientation="Horizontal"
                    DockPanel.Dock="Top"
                    Height="25">
                <TextBlock FontSize="14" Padding="0 0 8 0">
                    Search:
                </TextBlock>
                <TextBox x:Name="txtSearchTerm" Width="400" />
                <Image Source="/CarFinder;component/Images/Chrysanthemum.jpg" />            
            </StackPanel>
        </Border>
        <StackPanel Orientation="Horizontal"
                    DockPanel.Dock="Top"
                    Height="25">

        </StackPanel>
    </DockPanel>
</Window>

边框设置在整个窗口周围.而且,当我创建另一个StackPanel时,它会添加到我之前的StackPanel的右侧,而不是添加到它下面.这是什么原因？