In the tutorial "Add search functionality in DataGrid", the datagrid is declared as below:
<table id="tt" class="easyui-datagrid" style="width:700px;height:250px"
url="datagrid24_getdata.php"
title="Searching" iconCls="icon-search" toolbar="#tb"
rownumbers="true" pagination="true">
...
</table>
The 'nowrap' property is not set, set it to false to display rows with multiple lines.