c# - Command - binding from DataGridTemplateColumn -

<datagrid itemssource="{binding occerences}"            autogeneratecolumns="false"           isreadonly="true">     <datagrid.columns>         <datagridtextcolumn header="start index" binding="{binding start}" />         <datagridtextcolumn header="end index"  />         <datagridtextcolumn header="length"  />         <datagridtextcolumn header="pattern"  />         <datagridtemplatecolumn header="sequence">             <datagridtemplatecolumn.celltemplate>                 <datatemplate>                     <button content="sequence" command="{binding sequencecommand}" />                 </datatemplate>             </datagridtemplatecolumn.celltemplate>         </datagridtemplatecolumn>         <datagridtemplatecolumn header="export">             <datagridtemplatecolumn.celltemplate>                 <datatemplate>                     <button content="export" />                 </datatemplate>             </datagridtemplatecolumn.celltemplate>         </datagridtemplatecolumn>     </datagrid.columns>        </datagrid>   <button content="sequence" command="{binding sequencecommand}" /> 

this not working. how bind sequencecommand (myviewmodel, icommand sequencecommand)?

i can't use frameworks (mvvm light tool kit, prism, etc).

the datacontext in datatemplate celltemplate changed bind current item sequencecommand not found. have set relativesource datagrid , set path datacontext.sequencecommand this:

<button content="sequence"          command="{binding relativesource={relativesource ancestortype=datagrid},         path=datacontext.sequencecommand}" />