Remove trailing whitespace at the end of aspx file

I am trying to remove trailing whitespace including \r and \n at the end of aspx files by using Find and Replace using the pattern

\s+(?!.)

trying to replace whitespace followed by nothing with nothing.

The result is that everything will come on the same line.

Why?

I also tried \s+$ with the same result.

>Solution :

You may add a negative lookahead to the end of your current pattern:

(\s+\r?\n)+$(?!.)

This will ensure that only final lines with whitespace only are matched. See the demo here.