How to write this regex?

Question

I'm trying to replace all characters except letters, numbers and some special characters with whitespace. This is the line of code I'm using:

documentText = Regex.Replace(documentText, @"^((?![a-zA-Z0-9%\-\@\$&']).*)$", " ");

It doesn't work. I tested it on a sample text like this:

[]\^|+*(){} ~#%=/<>-!@$&_'",.?;:
this should stay

and it removes everything.

Answer 1

Use the following regex:

[^a-zA-Z0-9%\-@$&']

Using ^ inverts the character class, which is perfect for what you're looking for without using a negative lookahead.

Answer 2

你正在寻找。*这意味着0或者更多的任何角色....这就是为什么它会删除所有东西。