tks, I selected the second way and It`s OK.
But I don`t know reason.

If it`s not bug. do I need to remove this topic?

idField:'objectID',
columns:[[
         {field:'username',title:'username',width:200,sortable:true},
         {field:'action',title:'',width:50,formatter:function(value,row,rowIndex){
            var $_buttons = $("<div><a href='#' class='easyui-linkbutton' onclick='OPT_SYSTEMUSER_REMOVE("
                        + row.objectID + ");'></a></div>");
            $_buttons.find('.easyui-linkbutton').linkbutton({plain:true,iconCls:"icon-remove"});
            return $_buttons.html();
         }}
      ]],
-------------------------------------------
notice: the field 'action'
-------------------------------------------
OPT_SYSTEMUSER_REMOVE = function( _objectID ){
   $('#dataTabAll').datagrid('selectRecord',_objectID);
   var row = $('#dataTabAll').datagrid('getSelected');
   var index = $('#dataTabAll').datagrid('getRowIndex',row);
   $('#dataTabAll').datagrid('unselectRow',index);
   $('#dataTabAll').datagrid('deleteRow',index);
};
------------------------------------------
Bug Desc:
When I remove the last one, tip:" Uncaught TypeError: Cannot read property 'action' of undefined  " And Remove successfully.

[|| $.inArray(f.val(),val)>=0]

$('#id').form('load',data);  when checkbox, err
----------------------------------------------
Fix eg:
-------------------------
if(f.val()==String(val)){
$.fn.prop?f.prop("checked",true):f.attr("checked",true);
}
-------------------------
to
-------------------------
if(f.val()==String(val) || $.inArray(f.val(),val)>=0){
$.fn.prop?f.prop("checked",true):f.attr("checked",true);
}
-------------------------