How to use file in file system for HttpPostedFile
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20-12-2019 - |
문제
I have the following code for creating PDF Thumbnails, but this code only works for input files with HttpPostedFile. But my files are in the file system an I don't know how to handle them without HttpPostedFile. How can I create thumbnails of files in the file system?
This is the code:
<%@ Page language="c#" %>
<%@ Register TagPrefix="tc" Assembly="TallComponents.PDFThumbnail" Namespace="TallComponents.Web.PDF" %>
<script runat="server">
protected void DisplayThumbs_Click(object sender, System.EventArgs e)
{
thumbnails.Controls.Clear();
HttpPostedFile postedFile = Request.Files[ "pdf" ];
if ( null != postedFile )
{
byte[] buffer = new byte[ postedFile.ContentLength ];
postedFile.InputStream.Read( buffer, 0, buffer.Length );
string unique = Guid.NewGuid().ToString();
Session[ unique ] = buffer;
int n = Thumbnail.GetPageCount( postedFile.InputStream );
for ( int i=1; i<=n; i++ )
{
Thumbnail thumbnail = new Thumbnail();
thumbnail.SessionKey = unique;
thumbnail.Index = i;
thumbnails.Controls.Add( thumbnail );
}
}
}
</script>
<HTML>
<body>
<form id="Form1" method="post" runat="server" enctype="multipart/form-data">
<input width="100%" type="file" size="50" name="pdf" /> <br/>
<asp:button Runat="server" Text="Display thumbs" ID="DisplayThumbs" OnClick="DisplayThumbs_Click" /> <br/>
<asp:Panel ID="thumbnails" runat="server" />
</form>
</body>
</HTML>
Thanks in advance
해결책
If you use it to process a file-system based stream, you only need the "core logical code" from the asp.net code. You may use it like this:
private static IList<Thumbnail> GetThumbnails(System.IO.File pdfFile)
{
string unique = Guid.NewGuid().ToString();
using(System.IO.Stream stream = pdfFile.OpenRead())
{
int n = Thumbnail.GetPageCount( stream );
List<Thumbnail> thumbnails = new List<Thumbnail>();
for ( int i=1; i<=n; i++ ) // Note: please confirm the loop should really start from the index 1 (instead of 0?)
{
Thumbnail thumbnail = new Thumbnail();
thumbnail.SessionKey = unique;
thumbnail.Index = i;
thumbnails.Add( thumbnail );
}
return thumbnails;
}
}
다른 팁
You can use the SaveAs
function of the HttpPostedFile class to save and use the file,
here's the link that explains all: http://msdn.microsoft.com/en-us/library/system.web.httppostedfile.saveas(v=vs.110).aspx
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