eg:double n=2.50000; // or 250000
string resultstring=Format("{0:#.#}",n.) ;
eg:decimal d=00500;
d.ToString("0.##"); // .## 最多保留2位有效數字,但是不包含0。比如:d=0.5000,結果是0.5
eg:decimai d=0.0500;
string.Format("{0:0.##}",d000);
eg:string SubjectString = "2.500000";
string ResultString = null;
ResultString = Regex.Replace(SubjectString, "\\.?0*$", "");
eg:decimal.Parse( "2.50000" ).ToString();
eg:string str = "abcd000";
str = str.TrimEnd('0');
結果str為 "abcd"