https://www.cnblogs.com/xuliangxing/p/7993267.html
str = System.Text.RegularExpressions.Regex.Replace(str, @"[^0-9]+", "")
str = Regex.Replace(str, @"[^\d.\d]", "")//带小数点
2022-01-09 01:44:50
https://www.cnblogs.com/xuliangxing/p/7993267.html
str = System.Text.RegularExpressions.Regex.Replace(str, @"[^0-9]+", "")
str = Regex.Replace(str, @"[^\d.\d]", "")//带小数点