Flex DataGird导出到excel

/**
* Simple script to convert a Datagrid to a HTML table and then
* pass it on to an external excel exporter
*
*/

//Libs that are mostly used
//(only a number are necessary for the datagrid conversion and export)
import flash.errors.*;
import flash.events.*;
import flash.external.*;
import flash.net.URLRequest;
import flash.net.URLVariables;

/**
* Convert the datagrid to a html table
* Styling etc. can be done externally
*
* @param: dg Datagrid Contains the datagrid that needs to be converted
* @returns: String
*/
private function convertDGToHTMLTable(dg:DataGrid):String {
//Set default values
var font:String = dg.getStyle('fontFamily');
var size:String = dg.getStyle('fontSize');
var str:String = '';
var colors:String = '';
var style:String = 'style="font-family:'+font+';font-size:'+size+'pt;"';
var hcolor:Array;

//Retrieve the headercolor
if(dg.getStyle("headerColor") != undefined) {
hcolor = [dg.getStyle("headerColor")];
} else {
hcolor = dg.getStyle("headerColors");
}

//Set the htmltabel based upon knowlegde from the datagrid
str+= '<table width="'+dg.width+'" border="1"><thead><tr width="'+dg.width+'" style="background-color:#' +Number((hcolor[0])).toString(16)+'">';

//Set the tableheader data (retrieves information from the datagrid header
for(var i:int = 0;i<dg.columns.length;i++) {
colors = dg.getStyle("themeColor");

if(dg.columns[i].headerText != undefined) {
str+="<th "+style+">"+dg.columns[i].headerText+"</th>";
} else {
str+= "<th "+style+">"+dg.columns[i].dataField+"</th>";
}
}
str += "</tr></thead><tbody>";
colors = dg.getStyle("alternatingItemColors");

//Loop through the records in the dataprovider and
//insert the column information into the table
for(var j:int =0;j<dg.dataProvider.length;j++) {
str+="<tr width=\""+Math.ceil(dg.width)+"\">";

for(var k:int=0; k < dg.columns.length; k++) {

//Do we still have a valid item?
if(dg.dataProvider.getItemAt(j) != undefined && dg.dataProvider.getItemAt(j) != null) {

//Check to see if the user specified a labelfunction which we must
//use instead of the dataField
if(dg.columns[k].labelFunction != undefined) {
str += "<td width=\""+Math.ceil(dg.columns[k].width)+"\" "+style+">"+dg.columns[k].labelFunction(dg.dataProvider.getItemAt(j),dg.columns[k].dataField)+"</td>";

} else {
//Our dataprovider contains the real data
//We need the column information (dataField)
//to specify which key to use.
str += "<td width=\""+Math.ceil(dg.columns[k].width)+"\" "+style+">"+dg.dataProvider.getItemAt(j)[dg.columns[k].dataField]+"</td>";
}
}
}
str += "</tr>";
}
str+="</tbody></table>";

return str;
}

/**
* Load a specific datagrid into Excel
* This method passes the htmltable string to an backend script which then
* offers the excel download to the user.
* The reason for not using a copy to clipboard and then javascript to
* insert it into Excel is that this mostly will fail because of the user
* setup (Webbrowser configuration).
*
* @params: dg Datagrid The Datagrid that will be loaded into Excel
* @params: url String The location of the excel export file
*/
private function loadDGInExcel(dg:DataGrid,url:String):void {

//Pass the htmltable in a variable so that it can be delivered
//to the backend script
var variables:URLVariables = new URLVariables();
variables.htmltable    = convertDGToHTMLTable(dg);

//Setup a new request and make sure that we are
//sending the data through a post
var u:URLRequest = new URLRequest(url);
u.data = variables; //Pass the variables
u.method = URLRequestMethod.POST; //Don't forget that we need to send as POST

//Navigate to the script
//We can use _self here, since the script will through a filedownload header
//which results in offering a download to the user (and still remaining in you Flex app.)
navigateToURL(u,"_self");
}