C# 如何在dock panel中添加两个或更多按钮？

我正在使用WPF和DevExpress。我想在dock面板中添加两个按钮。当我添加第二个按钮时，它说：

内容设置了不止一次。为什么会这样？我有没有犯过什么错误，或者码头面板不允许这样做

<dxdo:DockLayoutManager Margin="0,-3,-156,0" HorizontalAlignment="Right" VerticalAlignment="Top" Background="White" Height="243" Width="109">
    <dxdo:LayoutGroup Caption="LayoutRoot" Margin="0,0,0,172">
        <dxdo:LayoutGroup Orientation="Vertical">
            <dxdo:LayoutPanel  x:Name="Panel1"  ShowCloseButton="False" ShowMaximizeButton="False" ShowPinButton="False" ShowRestoreButton="False" ShowControlBox="False" AllowDock="False" AllowDrag="False" AllowFloat="False" AllowHide="False" AllowClose="False" AllowActivate="False" AllowMinimize="False" AllowMaximize="False">
                <Button x:Name="ToggleButton1" Content="New" Click="ToggleButton_Click" HorizontalAlignment="Left" VerticalAlignment="Top"/>
                <Button Content="Delete Focused Row"
                Click="DeleteButton_Click33"
                Grid.Column="1" />
            </dxdo:LayoutPanel>
            <dxdo:LayoutPanel  x:Name="Panel2" ShowCloseButton="False" ShowMaximizeButton="False" ShowPinButton="False" ShowRestoreButton="False" ShowControlBox="False" AllowDock="False" AllowDrag="False" AllowFloat="False" AllowHide="False" AllowClose="False" AllowActivate="False" AllowMinimize="False" AllowMaximize="False">
                <Button x:Name="ToggleButton2" Content="Close" Click="ToggleButton2_Click" HorizontalAlignment="Left" VerticalAlignment="Top"/>
            </dxdo:LayoutPanel>
        </dxdo:LayoutGroup>
    </dxdo:LayoutGroup>
</dxdo:DockLayoutManager>

您可以在属性中放置多个控件。只需将按钮包装到面板中：

<dxdo:LayoutPanel ... >
    <StackPanel Orientation="Vertical">
        <Button x:Name="button1" ... />
        <Button x:Name="button2" ...  />
    </StackPanel>
</dxdo:LayoutPanel>



相关示例：
如何将它们放在同一行？@AnnieSheikh使用水平堆叠面板或任何其他适合您需要的面板。。。或者参考我链接的示例。或者甚至将DevExpress放入面板内容，并通过LayoutControl功能排列所有按钮。我可以在按钮之间添加空间吗？使用此布局控件：）