摘抄自 http://www.cnblogs.com/daxia/archive/2008/01/08/1030779.html
供学习之用
导入导出EXCEL
#region 导入导出EXCEL
/**//// <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 exportExcel(System.Web.UI.Page page, 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.LightGray;
datagrid.HeaderStyle.HorizontalAlign = HorizontalAlign.Center;
datagrid.HeaderStyle.Font.Bold = true;
datagrid.DataBind();
httpresponse.AppendHeader("content-disposition", "attachment;filename=" + HttpUtility.UrlDecode(filename, System.Text.Encoding.UTF8)); //filename="*.xls";
httpresponse.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
httpresponse.ContentType = "application/ms-excel";
System.IO.StringWriter tw = new StringWriter();
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);
datagrid.RenderControl(hw);
string filepath = page.Server.MapPath("..") + "\\ExcelFolder\\" + filename;
System.IO.StreamWriter sw = System.IO.File.CreateText(filepath);
sw.Write(tw.ToString());
sw.Close();
downfileForExcel(httpresponse, filename, filepath);
httpresponse.End();
}
private static bool downfileForExcel(System.Web.HttpResponse response, string filename, string fullpath)
{
try
{
response.ContentType = "application/octet-stream";
response.AppendHeader("content-disposition", "attachment;filename=" +
HttpUtility.UrlDecode(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;
}
}
/**//// <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 ImportExcel(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$]", conn);
OleDbDataAdapter myData = new OleDbDataAdapter(myOleDbCommand);
myData.Fill(rs);
conn.Close();
}
catch//如果数据连接可以打开但是读入数据失败，则从文件中提取出工作表的名称，再读入数据
{
string sheetName = GetSheetName(filePath);
if (sheetName.Length > 0)
{
OleDbCommand myOleDbCommand = new OleDbCommand("SELECT * FROM [" + sheetName + "$]", conn);
OleDbDataAdapter myData = new OleDbDataAdapter(myOleDbCommand);
myData.Fill(rs);
conn.Close();
}
}
}
else
{
System.IO.StreamReader tmpStream = File.OpenText(filePath);
string tmpStr = tmpStream.ReadToEnd();
tmpStream.Close();
rs = GetDataTableFromString(tmpStr);
tmpStr = "";
}
return rs;
}
/**//// <summary>
/// 将指定Html字符串的数据转换成DataTable对象 --根据“<tr><td>”等特殊字符进行处理
/// </summary>
/// <param name="tmpHtml">Html字符串</param>
/// <returns></returns>
private static DataTable GetDataTableFromString(string tmpHtml)
{
string tmpStr = tmpHtml;
DataTable TB = new DataTable();
//先处理一下这个字符串，删除第一个<tr>之前合最后一个</tr>之后的部分
int index = tmpStr.IndexOf("<tr");
if (index > -1)
tmpStr = tmpStr.Substring(index);
else
return TB;
index = tmpStr.LastIndexOf("</tr>");
if (index > -1)
tmpStr = tmpStr.Substring(0, index + 5);
else
return TB;
bool existsSparator = false;
char Separator = Convert.ToChar("^");
//如果原字符串中包含分隔符“^”则先把它替换掉
if (tmpStr.IndexOf(Separator.ToString()) > -1)
{
existsSparator = true;
tmpStr = tmpStr.Replace("^", "^$&^");
}
//先根据“</tr>”分拆
string[] tmpRow = tmpStr.Replace("</tr>", "^").Split(Separator);
for (int i = 0; i < tmpRow.Length - 1; i++)
{
DataRow newRow = TB.NewRow();
string tmpStrI = tmpRow[i];
if (tmpStrI.IndexOf("<tr") > -1)
{
tmpStrI = tmpStrI.Substring(tmpStrI.IndexOf("<tr"));
if (tmpStrI.IndexOf("display:none") < 0 || tmpStrI.IndexOf("display:none") > tmpStrI.IndexOf(">"))
{
tmpStrI = tmpStrI.Replace("</td>", "^");
string[] tmpField = tmpStrI.Split(Separator);
for (int j = 0; j < tmpField.Length - 1; j++)
{
tmpField[j] = RemoveString(tmpField[j], "<font>");
index = tmpField[j].LastIndexOf(">") + 1;
if (index > 0)
{
string field = tmpField[j].Substring(index, tmpField[j].Length - index);
if (existsSparator) field = field.Replace("^$&^", "^");
if (i == 0)
{
string tmpFieldName = field;
int sn = 1;
while (TB.Columns.Contains(tmpFieldName))
{
tmpFieldName = field + sn.ToString();
sn += 1;
}
TB.Columns.Add(tmpFieldName);
}
else
{
newRow[j] = field;
}
}//end of if(index>0)
}
if (i > 0)
TB.Rows.Add(newRow);
}
}
}
TB.AcceptChanges();
return TB;
}
/**//// <summary>
/// 从指定Html字符串中剔除指定的对象
/// </summary>
/// <param name="tmpHtml">Html字符串</param>
/// <param name="remove">需要剔除的对象--例如输入"<font>"则剔除"<font ???????>"和"</font>>"</param>
/// <returns></returns>
public static string RemoveString(string tmpHtml, string remove)
{
tmpHtml = tmpHtml.Replace(remove.Replace("<", "</"), "");
tmpHtml = RemoveStringHead(tmpHtml, remove);
return tmpHtml;
}
/**//// <summary>
/// 只供方法RemoveString()使用
/// </summary>
/// <returns></returns>
private static string RemoveStringHead(string tmpHtml, string remove)
{
//为了方便注释，假设输入参数remove="<font>"
if (remove.Length < 1) return tmpHtml;//参数remove为空：不处理返回
if ((remove.Substring(0, 1) != "<"||remove.Substring(remove.Length - 1) != ">"))
return tmpHtml;//参数remove不是<?????>：不处理返回
int IndexS = tmpHtml.IndexOf(remove.Replace(">", ""));//查找“<font”的位置
int IndexE = -1;
if (IndexS > -1)
{
string tmpRight = tmpHtml.Substring(IndexS, tmpHtml.Length - IndexS);
IndexE = tmpRight.IndexOf(">");
if (IndexE > -1)
tmpHtml = tmpHtml.Substring(0, IndexS) + tmpHtml.Substring(IndexS + IndexE + 1);
if (tmpHtml.IndexOf(remove.Replace(">", "")) > -1)
tmpHtml = RemoveStringHead(tmpHtml, remove);
}
return tmpHtml;
}
/**//// <summary>
/// 将指定Excel文件中读取第一张工作表的名称
/// </summary>
/// <param name="filePath"></param>
/// <returns></returns>
private static string GetSheetName(string filePath)
{
string sheetName = "";
System.IO.FileStream tmpStream = File.OpenRead(filePath);
byte[] fileByte = new byte[tmpStream.Length];
tmpStream.Read(fileByte, 0, fileByte.Length);
tmpStream.Close();
byte[] tmpByte = new byte[]{Convert.ToByte(11),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),
Convert.ToByte(11),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),
Convert.ToByte(30),Convert.ToByte(16),Convert.ToByte(0),Convert.ToByte(0)};
int index = GetSheetIndex(fileByte, tmpByte);
if (index > -1)
{
index += 16 + 12;
System.Collections.ArrayList sheetNameList = new System.Collections.ArrayList();
for (int i = index; i < fileByte.Length - 1; i++)
{
byte temp = fileByte[i];
if (temp != Convert.ToByte(0))
sheetNameList.Add(temp);
else
break;
}
byte[] sheetNameByte = new byte[sheetNameList.Count];
for (int i = 0; i < sheetNameList.Count; i++)
sheetNameByte[i] = Convert.ToByte(sheetNameList[i]);
sheetName = System.Text.Encoding.Default.GetString(sheetNameByte);
}
return sheetName;
}
/**//// <summary>
/// 只供方法GetSheetName()使用
/// </summary>
/// <returns></returns>
private static int GetSheetIndex(byte[] FindTarget, byte[] FindItem)
{
int index = -1;
int FindItemLength = FindItem.Length;
if (FindItemLength < 1) return -1;
int FindTargetLength = FindTarget.Length;
if ((FindTargetLength - 1) < FindItemLength) return -1;
for (int i = FindTargetLength - FindItemLength - 1; i > -1; i--)
{
System.Collections.ArrayList tmpList = new System.Collections.ArrayList();
int find = 0;
for (int j = 0; j < FindItemLength; j++)
{
if (FindTarget[i + j] == FindItem[j]) find += 1;
}
if (find == FindItemLength)
{
index = i;
break;
}
}
return index;
}
#endregion
