wpf DataGrid Scroll with mouseclick scrollBar Error when Row Drag and Drop -

i wrote dodragdrop in datagrid.

however, can't click , drag scroll bar on datagrid because drag error occurred.

but can scroll mouse wheel.

how can fix it? here part of code.

.cs file

private void datagrid_mousemove(object sender, mouseeventargs e)     {         if (e.leftbutton == mousebuttonstate.pressed)         {             point currentposition = e.getposition(incidentlist);             object selecteditem = datagrid.selecteditem;             if (selecteditem != null)             {                 datagridrow container = (datagridrow)datagrid.itemcontainergenerator.containerfromitem(selecteditem);                 var dataobj = new dataobject();                 dataobj.setdata("dragsource", container);                 if (container != null)                 {                      dragdrop.dodragdrop(container, dataobj, dragdropeffects.copy);                 }             }         }                 } 

.xaml file

<datagrid x:name="datagrid" columnheaderstyle="{staticresource mycolumnheader}"                style="{dynamicresource datagridstyle}" canuseraddrows="false" verticalalignment="stretch"               height="{binding relativesource={relativesource findancestor, ancestortype={x:type grid}}, path=actualheight}"               horizontalalignment="stretch" minheight="150" selectionmode="single"               itemssource="{binding mylistdata, updatesourcetrigger=propertychanged}" autogeneratecolumns="false"                           selecteditem="{binding selectmyrow}"                mousemove="datagrid_mousemove"> ..... 

register handler on row instead of datagrid:

<datagrid>     <datagrid.rowstyle>         <style targettype="datagridrow">             <eventsetter event="mousemove" handler="rowmovehandler"/>         </style>     </datagrid.rowstyle> 

and take sender-row container:

private void rowmovehandler(object sender, mouseeventargs e) {     var container = sender datagridrow;     if (container != null && e.leftbutton == mousebuttonstate.pressed)     {         var dataobj = new dataobject();         dataobj.setdata("dragsource", container);         dragdrop.dodragdrop(container,                     dataobj,                     dragdropeffects.copy);     } }