change toolbarhelper values override in the program
<p>in the following, I can't seem to change the _<em>StartDate</em> and _<em>EndDate</em>. I wanted to show data for only past week but the values are coming from toolbarhelper for past month, how can I over ride these to the past week only?</p>

<pre><code>protected override ObservableCollection&lt;Object&gt; CreateToolBar()
{
    return new ObservableCollection&lt;Object&gt;()
    {
        ToolBarHelper.PrintButton(),
        ToolBarHelper.DateRange(_StartDate, _EndDate, (s, e) =&gt; { _StartDate = s; _EndDate = e; }),
        ToolBarHelper.UnitSelection(unit =&gt; { _Unit = unit; }),
        ToolBarHelper.RefreshButton(RefreshData),
    };
}
</code></pre>
