crescenzo ha ragione. se devi caricare da un file estensione XML
file dati.xml
codice:
<elenco>
<item numero="50423" cod_ieri="PF50423" data="1"></item>
<item numero="2"  cod_ieri="PF50423" data="4"></item>
<item numero="3"  cod_ieri="PF50423" data="5"></item>
</elenco>
AS
codice:
stop();
import mx.controls.gridclasses.DataGridColumn;
//inizializza header

var columns = [
{label:"numero", width:100},
{label:"cod_ieri", width:250},
{label:"data", width:50}
];
for(var i = 0; i < columns.length; i++)
{
var column = new DataGridColumn(columns[i].label);
column.width = columns[i].width;
datagrid.addColumn(column);
}

var item = "";
var tot = 0;
var path = this;
dati_xml = new XML();
dati_xml.ignoreWhite = true;
dati_xml.onLoad = function(success)
{
path.datagrid.removeAll();
if (success) {
var nodes = this.firstChild.childNodes;
tot = nodes.length;
path.datagrid.dataProvider = nodes;
path.datagrid.setSelectedIndex(0);
} else {
path.datagrid.setEnabled(false);
}
};
dati_xml.load("dati.xml");

per il file di testo ovviamente la sintassi del caricamento e' differente.
il file di testo deve essere cosi':

file dati.txt
codice:
newsdata=50423|PF50423|356609962|10/08/2007||03617|179286|836675904|10/08/2007||
il simbolo "|" identifica la fine del contenuto della cella
il simbolo "||" identifica la fine della riga

AS
datagrid sullo stage istanziato "datagrid"
codice:
stop();
import mx.controls.DataGrid;
//inizializza header
var dp:Array = [];
var statusQuo:String = "";
var myNews:LoadVars = new LoadVars();
myNews.load("dati_xml.txt");
myNews.onLoad = function(success) {
if (success) {
var tmpArr:Array = this.newsdata.split("||");
for (var i:Number = 0; i<tmpArr.length-1; i++) {
dp[i] = {CODICE:tmpArr[i].split("|")[0],IERI:tmpArr[i].split("|")[1], OGGI:tmpArr[i].split("|")[2], DATA_VAR:tmpArr[i].split("|")[3] };
datagrid.editable = false;
datagrid.sortableColumns = true;
//datagrid.showHeaders = false;
datagrid.dataProvider = dp;
//datagrid.setStyle("borderStyle", "alert");
datagrid.setStyle("themeColor", 0xeeeeee);
datagrid.getColumnAt(0).width = 60;
datagrid.getColumnAt(0).setStyle("textAlign", "center");
datagrid.getColumnAt(1).width = 70;
datagrid.getColumnAt(1).setStyle("textAlign", "center");
datagrid.getColumnAt(2).width = 70;
datagrid.getColumnAt(2).setStyle("textAlign", "center");
datagrid.getColumnAt(3).width = 80;
datagrid.getColumnAt(3).setStyle("textAlign", "center");
//datagrid.getColumnAt(1).width = 200;
//datagrid.getColumnAt(2).width = 80;
//datagrid.getColumnAt(3).width = 100;
datagrid.resizableColumns = false;
//datagrid.setStyle("color", 0x5B6C80);
datagrid.setStyle("fontFamily", "Times");
datagrid.getColumnAt(3).setStyle("textAlign", "right");
datagrid.getColumnAt(2).setStyle("color", 0x43525F);
datagrid.getColumnAt(1).setStyle("color", 0x43525F);
datagrid.getColumnAt(0).setStyle("color", 0x43525F);
datagrid.vScrollPolicy = "auto";
//datagrid.getColumnAt(0).setStyle("fontWeight", "bold");
}
}
}