c# - Rename the Closed File -

when close c# window, hope append timestamp filename. however, when run following codes, got such error:

'system.notsupportedexception'

and

"the given path's format not supported.".

is there method modify parameters?

private void window_closed(object sender, eventargs e) {     sw_bea.close();     string file_time = datetime.now.tostring("h:mm:ss tt").tostring();     system.io.file.move(@"c:\users\abc\desktop\tmp_bea.txt", @"c:\users\abc\desktop\tmp_bea"+file_time+".txt"); } 

as have commented, proximate problem colons in filename.

in general, if want ensure filename doesn't contain illegal characters, can like

for (char c in path.getinvalidfilenamechars())     filename=filename.replace(c, '_');