ribbon:RibbonSplitButton check项目的添加

                <ribbon:RibbonSplitButton ToolTipDescription="{Resx Ribbon.StandDisplayGroup.ToolTip}"
                                          ToolTipTitle="{Resx Ribbon.StandDisplayGroup.ToolTipTitle}"
                                          KeyTip="DG"
                                          Label="{Resx Ribbon.DisplayGroup}"
                                          Name="DisplayGroupButton"
                                          LargeImageSource="pack://application:,,,/ResourcesClient.Modules.Stand;component/Resources/Images/selectresourcegroup32.png">
                    <ribbon:RibbonApplicationMenuItem Header="All" />
                    <ribbon:RibbonApplicationMenuItem  IsChecked="True"
                                                       Header="Stand Group 1" />
                    <ribbon:RibbonApplicationMenuItem IsChecked="True"
                                                      Header="Stand Group 2" />
                    <ribbon:RibbonApplicationMenuItem Header="Stand Group 3" />
                </ribbon:RibbonSplitButton>