Ion-pane with ion-nav-bar

i have a simple view as this:

<ion-nav-bar class="bar-energized">

details are removed. when i do this, the ion-pane appeared overlapped with nav-bar but it is supposed to be below it. i tried adding class=‘has-header’, it moves below but leaves a blank space after nav-bar making my pane content not shown completely. is there anyway to make ion-pane appear immediately after ion-nav-bar?