导出数据到Excel

/// <summary>
/// 导出数据到一个excel文件
/// </summary>
/// <returns>文件名称</returns>
public string ExportToExcel()
{
//You use these variables throughout the application.
string fileExcel;
string fileName;
string strLine;
FileStream objFileStream;
StreamWriter objStreamWriter;
Random nRandom = new Random(DateTime.Now.Millisecond);
//Create a random file name.
fileExcel = "t" + nRandom.Next().ToString() + ".xls";
//Set a virtual folder to save the file.
fileName = filePath + "\\" + fileExcel;
//Use FileSystem objects to create the .xls file.
objFileStream = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Write);
objStreamWriter = new StreamWriter(objFileStream,System.Text.Encoding.Default);
objStreamWriter.WriteLine(fileHeader);
//Reinitialize the string for data.
strLine = "";
//Enumerate the database that is used to populate the file.
for (int j=0;j<=DataDt.Rows.Count-1;j++)
{
for (int i = 0; i <=DataDt.Columns.Count-1; i++)
{
strLine = strLine +DataDt.Rows[j][i].ToString()+Convert.ToChar(9);
}
objStreamWriter.WriteLine(strLine);
strLine="";
}
//Clean up.
objStreamWriter.Close();
objFileStream.Close();
return filePath + "\\" + fileExcel;
//return fileExcel;
}