extjs 如何给column 加上提示

<script type="text/javascript" src="${pageContext.request.contextPath }/extjs/examples/simple-widgets/qtips.js"></script> renderer : function(value, metaData, record, rowIndex, colIndex, store) { // provide the logic depending on business rules // name of your own choosing to manipulate the cell // depending upon // the data in the underlying Record object. // metaData.css : String : A CSS class name to add // to the TD element of the cell. // metaData.attr : String : An html attribute // definition string to apply to // the data container element within the table // cell (e.g. 'style="color:red;"'). metaData.attr = 'ext:qtip="' + value + '"'; return value; }