extjs CheckboxSelectionModel单选

var sm= new Ext.grid.CheckboxSelectionModel({header:'',singleSelect:true});

var cm = new Ext.grid.ColumnModel([new Ext.grid.RowNumberer(), sm, {
align :'center',
header : '操作',
dataIndex : 'id',
width : 130,
renderer : function(value,cellData,record){
var content = '';
if(!Ext.isEmpty(record.get('parentid'))){
content = '上移 | 下移';
}
return content;
}
},{
align :'center',
header : '分类名称',
dataIndex : 'name',
width : 130
}
}]);