the datagrid's getChecked() dos not work right

[cdtuql]

when I  check the datagrid on the title and  uncheck  all the rows  later the getchecked method return  a row (the last row)。
the code like :
columns:[[ 
          {field:'checkf',title:'checked',width:150,checkbox:true},



var rows = $('#BaseInfo_Gasdispenser_datagrid').datagrid('getChecked');

thanks

[jarry]

Please look at this example https://www.jeasyui.com/demo/main/index.php?plugin=DataGrid&theme=default&dir=ltr&pitem=CheckBox%20Selection%20on%20DataGrid. It works fine.