各项技术对正则表达式的支持

.NET

System.Text.RegularExpressions

string s = "+.055";
Regex r = new Regex(@"^[+-]?(\d*\.\d+|\d+|\d+\.\d*)$", RegexOptions.IgnoreCase);
Match m = r.Match(s);
if (m.Success)
{
    double d = Convert.ToDouble(m.Value);
}