How to get head text in datagrid header renderer

[xiva]

Hi,
I will create a checkbox in one of datagrid's header. And I write a header
renderer.
Now I want to use the data grid's column header text as the label of the
checkbox, but I don't know how can I get the text.
And another question is, how can I operate the checkbox on the header?
I use an unskillful method, that is, bindng the checkbox with a variable in
the parent document.
in the renderer,
headCheckBox = createObjectClass(....)
parentDocument.headCheckBox = headCheckBox ;
When I want to operate the headerCheckBox, eg, set it to be selected, I always
operate on the one in parentDocument. But if I have multi columns in one
datagrid, this method won't work. It seems I have to write many header
renderers, each renderer for one header and binding to one of the variable in
parent document.
Can anybody give me some advise on any of the 2 issues?
Thanks a lot.
Qin

[xiva]

I have a solution of the issues. But it sounds a bit of silly.
First of all, in the headerRenderer of the datagrid, setValue(str:String,
item:Object, sel:Boolean), the "str" parameter refers to the datagrid column's
headerText.
Then, I get the columnIndex by match all the datagrid columns'
headertext,--hope there is no 2 columns with same headerText.
then, I extends mx datagrid column to myDataGridColumn. In the class, there's
another object, a checkBox, named as dgHeaderCheckBox
When create the datagrid, instead of <mx: DataGridColumn I use
<myDataGridColumn
Then in the headerRenderer, format getColumnAt(columnIndex) to
myDataGridColumn, and set the checkBox created by render to the dgHeaderCheckBox
then can get this checkbox by
myDataGridColum(datagrid.getItemAt(columnIndex)).d gHeaderCheckBox