问题
I'm trying to create a relative link in pdf file created with iTextSharp
everything works good with ASCII letters, but if I add other unicode symbols in path they are just skipped
This works fine:
Chunk chunk = new Chunk(text, font);
chunk.SetAnchor("./Attachments/1.jpg");
This creates incorrect link (link is created like this: //1.jpg, Вложения - part is missing):
Chunk chunk = new Chunk(text, font);
chunk.SetAnchor("./Вложения/1.jpg");
Is there any way to create correct link with unicode symbols? Thanks
回答1:
By using Chunk.SetAnchor in iText 5 you effectively generate an URI Action. The URI parameter thereof is specified as
URI ASCII string (Required) The uniform resource identifier to resolve, encoded in 7-bit ASCII.
(ISO 32000-1, Table 206 – Additional entries specific to a URI action)
Thus, it can be considered ok that non-ASCII characters like your Cyrillic ones are not accepted by Chunk.SetAnchor. (It is not ok, though, that they are simply dropped; if the method does not accept its input, it should throw an exception.)
But by no means does that mean you cannot reference a file in a path that is using some non-ASCII characters. Instead you can make use of the fact that the path is considered an URI: This in particular means that you can apply the URL encoding scheme for special characters!
Thus, simply replace
chunk.SetAnchor("./Вложения/1.jpg");
by
chunk.SetAnchor(WebUtility.UrlEncode("./Вложения/1.jpg"));
and your link works again! (At least it did in my tests.)
PS: In .Net you actually have quite a choice of classes to do the URL encoding, cf. for example this answer. WebUtility.UrlEncode worked for me in the case at hand but depending on your use case one of the others might be more appropriate.
PPS: The situation changes a bit in the newer PDF specification:
URI ASCII string (Required) The uniform resource identifier to resolve, encoded in UTF8.
(ISO 32000-2, Table 210 — Additional entries specific to a URI action)
(I think the "ASCII" in the type column is a specification error and the UTF8 in the value column is to be taken seriously.)
But iText 5 has no PDF 2.0 support and, therefore, does not support UTF8 encoding here. One should probably test with iText 7 which claims PDF 2.0 support...
来源：https://stackoverflow.com/questions/53264518/unicode-symbols-in-itextsharp-relative-link