我有以下问题:
我正在将 ASP.Net GridView 直接导出到 excel 文件。
我在此方法中将图像设置为标题:
private static void insertPageHeaderFooter(ExcelInterfaceSoftArtisans excel,DateTime generatedDateTime)
{
StringBuilder builderFooterLeft = new StringBuilder();
builderFooterLeft.Append("&08Comfone AG Tel: +41 31 341 10 10");
builderFooterLeft.Append("\r");
builderFooterLeft.Append("&08Nussbaumstrasse 25 Fax: +41 31 341 10 11");
builderFooterLeft.Append("\r");
builderFooterLeft.Append("&08CH-3000 Bern 22 www.comfone.com");
StringBuilder builderFooterRight = new StringBuilder();
String sDateTime = generatedDateTime.ToString(CultureInfoHandler.ShortDateShortTimeFormat);
builderFooterRight.Append("&08&F");
builderFooterRight.Append("\r");
builderFooterRight.Append(string.Format("&08 {0}", sDateTime));
builderFooterRight.Append("\r"); //new line
builderFooterRight.Append("&08Page &P of &N");
excel.SetHeader("&G", 0.6, HeaderFooterSection.Section.Left, false);
excel.SetFooter(builderFooterLeft.ToString(), HeaderFooterSection.Section.Left, false);
excel.SetFooter(builderFooterRight.ToString(), HeaderFooterSection.Section.Right, false);
}
protected void SetHeader(string sText, double dImageSizeFactor, HeaderFooterSection.Section section, Worksheet sheet)
{
string headerAbsolutePath = HttpContext.Current.Server.MapPath("~/Resources/Mandates/CHECF.png");
Stream imageStream = new FileStream(headerAbsolutePath, FileMode.Open, FileAccess.Read);
Size imageSize = Image.FromStream(imageStream).Size;
imageStream = new FileStream(headerAbsolutePath, FileMode.Open, FileAccess.Read);
HeaderFooterSection header = sheet.PageSetup.GetHeader(section);
header.SetContent(sText, imageStream);
header.SetContent(sText);
header.GetPicture().Height = (int)(imageSize.Height * dImageSizeFactor);
header.GetPicture().Width = (int)(imageSize.Width * dImageSizeFactor);
imageStream.Close();
}
正如你在最后一行看到的,我关闭了 Stream。
现在,我想以这种方式保存我的 excel 文件:
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
excel.SaveWorkbook(sFileName, HttpContext.Current.Response, false);
/// <summary>
/// Saves the current Workbook under the given filename
/// </summary>
/// <param name="filename"></param>
/// <param name="response"></param>
/// <param name="openInBrowser"></param>
public void SaveWorkbook(string filename, HttpResponse response, bool openInBrowser)
{
if (book != null)
{
application.Save(book, response, filename, openInBrowser);
}
}
但是当我在 SetHeader 方法中关闭流时,出现以下错误:
Error Message: Cannot access a closed file.
Stack Trace: at System.IO.__Error.FileNotOpen()
at System.IO.FileStream.Seek(Int64 offset, SeekOrigin origin)
当我不关闭 SetHeader 方法中的流时,文件被正确保存。
你知道这个错误吗?我怎么可能需要打开流才能保存 excel 文件?我能做些什么来解决这个问题?
我附上了我正在使用的整个课程,这样你就可以更好地识别问题。
感谢您对此问题的快速回答和解决方案。