正则表达式和字符串

Question

Consider the following:

string keywords = "(load|save|close)";
Regex x = new Regex(@"\b"+keywords+"\b");

I get no matches. However, if I do this:

Regex x = new Regex(@"\b(load|save|close)\b");

I get matches. How come the former doesn't work, and how can I fix this? Basically, I want the keywords to be configurable so I placed them in a string.

Answer 1

The last \\b in the first code snippet needs a verbatim string specifier ( @ ) in front of it as well as it is a seperate string instance.

string keywords = "(load|save|close)"; 
Regex x = new Regex(@"\b"+keywords+@"\b");  

Answer 2

您缺少另一个逐字字符串说明符（ @末尾\\b前缀）：

Regex x = new Regex(@"\b" + keywords + @"\b");

Answer 3

Regex x = new Regex(@"\b"+keywords+@"\b");

您在第二个"\\b"之前忘记了其他@