String.Replace无法正常工作

Question

I have the following problem with String.Replace:

string str = "0˄0";
str = str.Replace("˄", "&&");

when I print out str, it will be "0&0" instead of "0&&0". To get "0&&0", I have to write

str = str.Replace("˄", "&&&&");

Why is that?

Answer 1

& is a special character in WinForms, used to indicate keyboard shortcuts. Using && is how WinForms escapes the & symbol.

So, to display it in WinForms you are necessarily going to have to place two & characters in your string as you have here:

str = str.Replace("˄", "&&&&");

This is strictly a WinForms "thing" and has nothing to do with a C# or .NET string escaping specifically. It has been this way at least as far back as Visual Basic 4 - probably before then.

Answer 2

You may want to check out this post: http://moiashvin-tech.blogspot.com/2008/05/escape-ampersand-character-in-c.html

Labels are handled differently in WinForms. You should be able to do as the post suggests and set the UseMnemonic property to false, see if that works.

Answer 3

The answer is in the first comment - '&' is a special character for WinForms (and the underlying Win32 API) which is/was used to indicate a shortcut character for menu/dialog items.

'&' in strings means nothing special to C#, but if you want to put it on a form/dialog label, then you need to escape the '&' by adding another one in front.

Personally, I would get the string how I really wanted it in my 'business logic' first, then escape the '&' characters as part of displaying the string on the form.