getEditor: Get the specified editor, the options contains two properties:
index: the row index.(正在编辑的行的下标,从0开始)
field: the field name.(编辑的列名称,column配置的)
var ed = $('#dg').datagrid('getEditor', {index:1,field:'svrCustNo'});
var value=$(ed.target).combobox('getValue')
alert(value)