wpf - Modal Window with MVVM pattern -

i trying make modal dialog window let user know error messages, or let user edit values. using mvvm pattern, mainwindow has control part , workspace part. in workspace part, opening viewmodels tight datatemplate views (defined usercontrols). 1 of these views want open modal dialog window. following answer error window show modal in mvvm wpf. described in answer, have implemented dialogclass in invoiceviewmodel. have problem showing content of modal window. if set content of window viewmodel class, output simple text namespace path viewmodel. (viewmodel attached view datatemplate.) if set content view - working - view showed but, disobeing mvvm pattern (opening view viewmodel viewmodel has no reference view).

        errorviewmodel newerrorviewmodel = new errorviewmodel();         errorview newerrorview = new errorview();         dialogwindow dialogwindow = new dialogwindow();         //not working         //dialogwindow.content = newerrorviewmodel;          //working but, breaking mvvm          dialogwindow.content = newerrorview;         dialogwindow.showdialog(); 

in errorview.xaml have attached errorviewmodel this.

<datatemplate datatype="{x:type vm:errorviewmodel}">     <vw:errorview/> </datatemplate> 

what doing wrong?

thanks.

you assigning newerrorview dialog's content, instead of newerrorviewmodel