C# Excel导入导出

/// <summary>
/// 导出Excel
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="list">数据源List<T></param>
/// <param name="fileName">页面文件 输出名称 *.xls</param>
public void Export<T>(IList<T> list, string fileName)
{

//得到DataTable
System.Data.DataTable dt = ListToTableHelper.ToDataTable(list);

//导出Excel的临时文件
string exportPath = Server.MapPath("~/Excel/") + DateTime.Now.Ticks + fileName;

CreateExcel(dt, exportPath);
FileInfo fileInfo = new FileInfo(exportPath);
if (fileInfo.Exists)
{
const long ChunkSize = 102400;//100K 每次读取文件，只读取100K，这样可以缓解服务器的压力
byte[] buffer = new byte[ChunkSize];
Response.Clear();
System.IO.FileStream iStream = System.IO.File.OpenRead(exportPath);
long dataLengthToRead = iStream.Length;//获取下载的文件总大小
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));
while (dataLengthToRead > 0 && Response.IsClientConnected)
{
int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小
Response.OutputStream.Write(buffer, 0, lengthRead);
Response.Flush();
dataLengthToRead = dataLengthToRead - lengthRead;
}
iStream.Close();
Response.Close();
}

// 删除生成的Excel 临时文件
File.Delete(exportPath);

}

/// <summary>
/// 打开模板Excel,重新写入 另存Excel 文件格式 xls 97-2003
/// </summary>
/// <param name="dt"></param>
/// <param name="excelPath"></param>
/// <param name="tempExcelPath"></param>
public void CreateExcel(System.Data.DataTable dt, string savePath)
{
savePath = savePath.Replace("/", "\\");
Application application = new ApplicationClass();
application.Visible = false;

//创建 新的Excel
Workbook workbook = application.Workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);

//插入 现有的Excel
//application.Workbooks._Open(tempExcelPath, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);
Worksheet worksheet = (Worksheet)workbook.Sheets[1];
int rowNum = 1;
int excelColumNum = 0;
try
{
int count = dt.Rows.Count;

for (int i = 0; i < dt.Columns.Count; i++)
{
worksheet.Cells[1, i + 1] = dt.Columns[i].ColumnName;
Range range = (Microsoft.Office.Interop.Excel.Range)worksheet.Cells[1, i + 1];
range.Interior.ColorIndex = 15;
range.Font.Bold = true;
}

foreach (System.Data.DataRow row in dt.Rows)
{
rowNum++;
//Console.WriteLine("当前处理记录:{0}/{1}", rowNum, count);
for (int i = 1; i <= dt.Columns.Count; i++)
{
excelColumNum = i;
string text = row[i - 1].ToString();
Range range = (Range)worksheet.Cells[rowNum, excelColumNum];
range.Value2 = text;
}
}
workbook.Saved = true;
workbook.SaveAs(savePath, XlFileFormat.xlExcel8, Missing.Value, Missing.Value, Missing.Value, Missing.Value, XlSaveAsAccessMode.xlNoChange, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);

workbook.Close(true, Type.Missing, Type.Missing);
workbook = null;
application.Quit();
GC.Collect();
}
catch
{
workbook.Saved = false;
workbook.Close(true, Type.Missing, Type.Missing);
workbook = null;
application.Quit();
GC.Collect();
}

}

protected void btn_ExportExcel_Click(object sender, EventArgs e)
{

IList<SongInfo> list = new List<SongInfo>();// 数据源

string fileName = "data.xls"; //页面文件 输出名称
Export(list, fileName);  //调用方法

ScriptManager.RegisterStartupScript(this, this.GetType(), "", "alert('成功!')", true); //完成后显示消息
}