No. I think there is no working solution for all pdf files, since the actual text underlaying the displayed visual text can be stored in various flavours.
When pdfs are generated by LaTeX for example, it depends on several configuration options, how some non-ascii-characters are embedded. Sometimes I got :o
instead of ö
, sometimes o:
and sometimes the character was embedded directly. Each of these variants where displayed as ö
though.
If you copy and paste the text with your favorite pdf-viewer or try to search for the corrupted word, you perhaps will see the same effects.
To come around those issues one may use ocr software - with all disadvantages on recognition of these tools.