先。IOException:由另一个进程使用的文件。

I've been working on this small piece of code that seems trivial but still, i cannot really see where is the problem. My functions do a pretty simple thing. Opens a file, copy its contents, replace a string inside and copy it back to the original file (a simple search and replace inside a text file then). I didn't really know how to do that as I'm adding lines to the original file, so I just create a copy of the file, (file.temp) copy also a backup (file.temp) then delete the original file(file) and copy the file.temp to file. I get an exception while doing the delete of the file. Here is the sample code:I've been working on this small piece of code t