dynamically change the fields shown in a datagrid

TracySchloss

I have a map services with many fields.  There are logical names to the fields like "Pasture_2002_Acres", Pasture_2007_Acres", "Crops_2002_Acres", "Crops_2007_Acres"

I created an array of fields that I'd like to have show up in a datagrid.  Based on whether the user wants to see Pasture information vs Crop information, the fields you'd want to see would be different.

I've run a querytask that generates a graphics layer and it contains all the attributes.  If the user wants to see just Pasture information, I made an array of just the fields related to that.  These become the fieldnames for a newly creaed datagrid.  The year is set from a radio button.  The results is an ArrayCollection I populated during the OnResults function of the querytask and it does have the right data in it.

   var fieldNameArray:Array = ["COUNTY","SQMILES",year+"_PASTURE_ACRES",year+"_PASTURE_SQMILES_TREATED",year+"_ PCTAREA_PASTURE"]; var selectDGcolumns:Array = [];    for each (var fieldName:String in fieldNameArray) {     var dgColumn:DataGridColumn = new DataGridColumn;     dgColumn.dataField = fieldName;     trace (dgColumn.dataField);     dgColumn.setStyle("textAlign","right");     selectDGcolumns.push(dgColumn);     }    dg.columns = selectDGcolumns;    dg.dataProvider = results;

This works just great the first time around. I have an "Open Table" button that opens a titleWindow that displays the datagrid.   The grid populates with the fields and values I expect.  The problem comes in when I want to change to a different subject.

The field array traces just fine (shows the change in the year).But when I go back through the 'for each' loop, the columns in the datagrid continue to be the ones I had chosen from the first time I used the tool.  I think I have emptied the array out by maybe I'm not understanding how to empty out all my arrays etc properly.

TracySchloss

There is no 'removeAll' option on the data provider.  The dg.columns = [];  sounded promising.  But no go!

I have the datagrid as a separate custom component (it has listeners etc back to the graphicslayer) and the titlewindow is also custom.

I'm making a new datagrid each time

var dg:Fields_DataGrid = new Fields_DataGrid;

but the titlewindow was a variable set at the top.  This turned out to be the problem, I needed to create a new one.  (You'd think I would have seen a bunch of datagrid all getting added to the same titlewindow, but it didn't work out that way!)

Thanks for your assistance, I need an extra pair of eyes, and I don't have anyone around me to ask!