c# - Black Background occurs when using microsoft.windows.shell -

i using microsoft.windows.shell customize wpf window chrome. fine until added datagrid. problem appearance of window become black sometimes. situation not happen constantly! looks fine has black background. here xaml code:

<window x:class="codegeneratorwpf.config"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         title="config" height="300" width="300" style="{staticresource mainwindowstyle}"          windowstartuplocation="centerowner" loaded="window_loaded">     <grid>         <grid.rowdefinitions>             <rowdefinition height="*"/>             <rowdefinition height="40"/>         </grid.rowdefinitions>         <datagrid name="datagrid" grid.row="0" itemssource="{binding data}"                    alternatingrowbackground="{staticresource {x:static systemcolors.controlbrushkey}}"                    cliptobounds="true" verticalgridlinesbrush="{dynamicresource {x:static systemcolors.controllightbrushkey}}"                   horizontalgridlinesbrush="{dynamicresource {x:static systemcolors.controllightbrushkey}}"                    loadingrow="datagrid_loadingrow">             <datagrid.rowheadertemplate>                 <datatemplate>                     <textblock text="{binding relativesource={relativesource ancestortype=datagridrow},                     path=header}"/>                 </datatemplate>             </datagrid.rowheadertemplate>         </datagrid>         <grid grid.row="1">             <grid.columndefinitions>                 <columndefinition width="*"/>                 <columndefinition width="*"/>             </grid.columndefinitions>             <button name="btnsave" grid.column="0" content="save" style="{staticresource emphasizebutton}" horizontalalignment="stretch" margin="25,5,25,5" click="btnsave_click"/>             <button name="btncancel" grid.column="1" content="cancel" style="{staticresource normalbutton}" margin="25,5,25,5" click="btncancel_click"/>         </grid>     </grid> </window> 

the mainwindowstyle:

             <!--captions buttons control window borderless-->             <dockpanel grid.row="0">                 <dockpanel.background>                     <solidcolorbrush color="#ff5d91dc"></solidcolorbrush>                 </dockpanel.background>                 <image name="imgtitle" source="{templatebinding icon}" dockpanel.dock="left" margin="5"></image>                 <label content="{templatebinding title}" foreground="white"></label>                 <ctrl:captionbuttons  margin="0,0,0,0" grid.row="0" horizontalalignment="right" type="full"                                     foreground="{dynamicresource captionbuttoncolor}" fontsize="14" marginbutton="0,0,5,0"                                     verticalalignment="center" shell:windowchrome.ishittestvisibleinchrome="true">                  </ctrl:captionbuttons>             </dockpanel>             <contentpresenter margin="0" grid.row="1" content="{templatebinding content}"/>         </grid>     </border>  </controltemplate>  <style x:key="mainwindowstyle" targettype="{x:type window}">     <setter property="shell:windowchrome.windowchrome">         <setter.value>             <shell:windowchrome                     resizeborderthickness="6"                     captionheight="25"                     cornerradius="0"                     glassframethickness="0,0,0,1" />         </setter.value>     </setter>     <setter property="template" value="{staticresource mainwindowcontroltemplate}"/> </style> 

can help?