Who can tell me how to use flex advanceddatagrid?

Note:The first column is the tree with checkbox.

 

For more information, see:

Labelfield is unable to display the attributes of the Element Object (carinfo. car_name). It seems that only attributes of the same level can be displayed. How can this problem be solved? Hope you can help me, thanks!

 

<Mx: advanceddatagrid id = "ADG" width = "100%" Height = "100%" dataprovider = "{instance. Cars }"
Variablerowheight = "true" wordwrap = "true" verticalgridlinecolor = "0x339900" headercolors = "[0x339900, 0 xffebcd]" horizontalgridlinecolor = "0x8b4513">
<Mx: columns>
<Mx: advanceddatagridcolumn headertext = "vehicle Name" datafield = "carinfo. car_name"/>
<Mx: advanceddatagridcolumn headertext = "terminal key" datafield = "carinfo. terminal_key"/>
<Mx: advanceddatagridcolumn headertext = "SIM code" datafield = "carinfo. sim_code"/>
</MX: columns>
</MX: advanceddatagrid>

 

/***** VO. Car ****/

[Bindable]

Public class car
{
Private VaR _ term: baseterminal;
Private VaR _ imagename: string;
Private VaR _ icon: icon;
Private VaR _ carinfo: carinfo;

...............

}

 

 

[Bindable]
[Remoteclass (alias = "VO. Car")]
Public class carinfo
{
Public var car_name: string;
Public var car_id: string;
Public var group_name: string;
Public var speed: int;
Public var terminal_key: string;
Public var sim_code: string;
Public var fuel_min: int;
Public var fuel_max: int;
Public var fuel_size: int;

...........

}