RegExp驗證小數點2位

^[0-9]+(.[0-9]{2})?$

demo:
https://regex101.com/r/CizAEg/1

RegExp驗證台灣手機門號10碼

^(?=.*[0])^(?=.*[9])(?=.*[0-9]).{10,10}$

demo:
https://regex101.com/r/3KRRPn/1

RegExp判斷密碼必須是6~7碼英數字(至少需要一個數字和一個英文字)

^(?=.*\d)(?=.*[a-zA-Z]).{6,7}$


Demo:
https://regex101.com/r/jza4od/1



使用 Regular Expression 驗證密碼複雜度
http://blog.miniasp.com/post/2008/05/09/Using-Regular-Expression-to-validate-password.aspx

參考保哥部落格寫法

1. 至少有一個數字 => (?=.*\d)
2. 至少有一個大寫或小寫英文字母 =>(?=.*[a-zA-Z])
3. 至少有一個特殊符號 =>(?=.*\W) =>不是數字、字母、底線[azAZ09_]
4. 字串長度在 6 ~ 30 個字母之間  =>.{6,30}

^(?=.*\d)(?=.*[a-zA-Z])(?=.*\W).{6,30}$

 demo:
https://regex101.com/r/Xobl5s/1

RegExp判斷五碼數字(郵遞區號5碼)

^\d{5}$

demo:
https://regex101.com/r/o2TPJ0/1


NNN|NNNNN
^[0-9]{3,3}|[0-9]{5,5}$
https://msdn.microsoft.com/zh-tw/library/partnercenter/dn974938.aspx

利用FileHelpers檢查csv格式

先把你的專案檔打開
在Visual Studio的套件管理器主控台輸入Install-Package FileHelpers

安裝完畢後，你的專案就會出現FileHelpers參考被引用、packages.config
 

如果無法使用Install-Package方式安裝
可以下載編譯好的DLL: FileHelpers_3.1.5_Build.zip (目前最新版本)
原始碼可以到該專案的Github下載
需要建立一個對映的Record Mapping Class
如果csv檔不符合對映就會出FileHelpers.BadUsageException





 


另一種處理CSV工具:CsvHelper
使用 CsvHelper - Part.2 資料讀取
http://kevintsengtw.blogspot.tw/2015/04/csvhelper-part2.html

REF:
How to validate a .csv file before storage in C#?
http://stackoverflow.com/questions/16608486/how-to-validate-a-csv-file-before-storage-in-c

How to validate CSV in C#?
http://stackoverflow.com/questions/24765492/how-to-validate-csv-in-c

C#判斷使用者輸入的本機路徑路徑是有效的

在stackoverflow看到的一片文章:Check if a string is a valid Windows directory (folder) path
可以使用Path.GetFullPath去判斷使用者輸入的本機路徑路徑是有效的
如果是無效的會丟出System.ArgumentException
只是空白字元算有效字元，如果怕使用者誤多輸入空白，可以自己判斷
if (inputPath.Contains(" ") )

Naming Files, Paths, and Namespaces
https://msdn.microsoft.com/en-us/library/aa365247

Use any character in the current code page for a name, including Unicode characters and characters in the extended character set (128–255), except for the following:

• The following reserved characters:
  • < (less than)
  • > (greater than)
  • : (colon)
  • " (double quote)
  • / (forward slash)
  • \ (backslash)
  • | (vertical bar or pipe)
  • ? (question mark)
  • * (asterisk)
• Integer value zero, sometimes referred to as the ASCII NUL character.
• Characters whose integer representations are in the range from 1 through 31, except for alternate data streams where these characters are allowed. For more information about file streams, see File Streams.
• Any other character that the target file system does not allow.

What characters are forbidden in Windows and Linux directory names?
http://stackoverflow.com/questions/1976007/what-characters-are-forbidden-in-windows-and-linux-directory-names