RegEx用于C＃中的模式

Question

I am still learning RegEx so I need some help on this one. 我仍在学习RegEx，因此在此方面需要一些帮助。

Rules are as below: 规则如下：

Min/Max Length of string: 1-5 最小/最大字符串长度：1-5
String has to be a whole word 字符串必须完整
String can contain: AZ and/or az and/or 0-9 or combination of both only (eg _ - . * are not allowed) 字符串可以包含：AZ和/或z和/或0-9或仅两者的组合（例如_-。*不允许）

Examples: 例子：

12345 – allowed
Os342 – allowed
2O3d3 – allowed
3sdfds dsfsdf – not allowed
Sdfdf.sdfdf –now allowed

Answer 1

What about: 关于什么：

string input = "12345";
bool match = Regex.IsMatch(input, "^[a-z0-9]{1,5}$", RegexOptions.IgnoreCase);

Answer 2

怎么样

^[A-Za-z0-9]{1,5}$

Answer 3

^[a-zA-Z0-9]{1,5}$

[a-zA-Z0-9] specifies the ranges allowed [a-zA-Z0-9]指定允许的范围
^ specifies start of string ^指定字符串的开头
$ specifies end of string $指定字符串的结尾
{1,5} indicates minimum and maximum number of characters for the range {1,5}表示该范围的最小和最大字符数