Hi tmark
Try using the fitColumns option. ie
<table id="dg" class="easyui-datagrid" title="DataGrid with Toolbar" data-options="fitColumns:true, fit:true">
<thead>
<tr>
<th field="itemid" width="100%">Col 1</th>
</tr>
</thead>
<tbody>
<tr>
<td>7</td>
</tr>
</tbody>
</table>
Note: I had to set the column width to 100%. Without this, the column width is first set to a calculated width (header text width). Then when you resize the column (does not matter what size), it automatically jumps to the max size.