DataTable中的数据导出Excel文件
/// <summary>
/// 将DataTable中的数据导出到指定的Excel文件中
/// </summary>
/// <param name="page">Web页面对象</param>
/// <param name="tab">包含被导出数据的DataTable对象</param>
/// <param name="FileName">Excel文件的名称</param>
public static void Export(System.Web.UI.Page page,System.Data.DataTable tab,string FileName)
{
System.Web.HttpResponse httpResponse = page.Response;
System.Web.UI.WebControls.DataGrid dataGrid=new System.Web.UI.WebControls.DataGrid();
dataGrid.DataSource=tab.DefaultView;
dataGrid.AllowPaging = false;
dataGrid.HeaderStyle.BackColor = System.Drawing.Color.Green;
dataGrid.HeaderStyle.HorizontalAlign = HorizontalAlign.Center;
dataGrid.HeaderStyle.Font.Bold = true;
dataGrid.DataBind();
httpResponse.AppendHeader("Content-Disposition","attachment;filename="+HttpUtility.UrlEncode(FileName,System.Text.Encoding.UTF8)); //filename="*.xls";
httpResponse.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");
httpResponse.ContentType ="application/ms-excel";
System.IO.StringWriter tw = new System.IO.StringWriter() ;
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter (tw);
dataGrid.RenderControl(hw);

string filePath = page.Server.MapPath("..")+"\\Files\\" +FileName;
System.IO.StreamWriter sw = System.IO.File.CreateText(filePath);
sw.Write(tw.ToString());
sw.Close();

DownFile(httpResponse,FileName,filePath);

httpResponse.End();
}
private static bool DownFile(System.Web.HttpResponse Response,string fileName,string fullPath)
{
try
{
Response.ContentType = "application/octet-stream";

Response.AppendHeader("Content-Disposition","attachment;filename=" +
HttpUtility.UrlEncode(fileName,System.Text.Encoding.UTF8) + ";charset=GB2312");
System.IO.FileStream fs= System.IO.File.OpenRead(fullPath);
long fLen=fs.Length;
int size=102400;//每100K同时下载数据
byte[] readData = new byte[size];//指定缓冲区的大小
if(size>fLen)size=Convert.ToInt32(fLen);
long fPos=0;
bool isEnd=false;
while (!isEnd)
{
if((fPos+size)>fLen)
{
size=Convert.ToInt32(fLen-fPos);
readData = new byte[size];
isEnd=true;
}
fs.Read(readData, 0, size);//读入一个压缩块
Response.BinaryWrite(readData);
fPos+=size;
}
fs.Close();
System.IO.File.Delete(fullPath);
return true;
}
catch
{
return false;
}
}

将指定Excel文件中的数据转换成DataTable
/// <summary>
/// 将指定Excel文件中的数据转换成DataTable对象，供应用程序进一步处理
/// </summary>
/// <param name="filePath"></param>
/// <returns></returns>
public static System.Data.DataTable Import(string filePath)
{
System.Data.DataTable rs = new System.Data.DataTable();
bool canOpen=false;

OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;"+
"Data Source=" + filePath + ";" +
"Extended Properties=\"Excel 8.0;\"");

try//尝试数据连接是否可用
{
conn.Open();
conn.Close();
canOpen=true;
}
catch{}

if(canOpen)
{
try//如果数据连接可以打开则尝试读入数据
{
OleDbCommand myOleDbCommand = new OleDbCommand("SELECT * FROM [Sheet1$]",conn);
OleDbDataAdapter myData = new OleDbDataAdapter(myOleDbCommand);
myData.Fill(rs);
conn.Close();
}
catch//如果数