检查电子邮件地址在 iOS 上是否有效

问题描述:

可能的重复:
验证电子邮件地址的最佳做法在 iOS 2.0 上的 Objective-C 中?

我正在开发一个 iPhone 应用程序,我需要用户在登录时提供他的电子邮件地址.

I am developing an iPhone application where I need the user to give his email address at login.

检查电子邮件地址是否为有效电子邮件地址的最佳方法是什么?

What is the best way to check if an email address is a valid email address?

好可可功能:

-(BOOL) NSStringIsValidEmail:(NSString *)checkString
{
   BOOL stricterFilter = NO; // Discussion http://blog.logichigh.com/2010/09/02/validating-an-e-mail-address/
   NSString *stricterFilterString = @"^[A-Z0-9a-z\._%+-]+@([A-Za-z0-9-]+\.)+[A-Za-z]{2,4}$";
   NSString *laxString = @"^.+@([A-Za-z0-9-]+\.)+[A-Za-z]{2}[A-Za-z]*$";
   NSString *emailRegex = stricterFilter ? stricterFilterString : laxString;
   NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
   return [emailTest evaluateWithObject:checkString];
}

关于松散与严格的讨论 - http://blog.logichigh.com/2010/09/02/validating-an-e-mail-address/

Discussion on Lax vs. Strict - http://blog.logichigh.com/2010/09/02/validating-an-e-mail-address/

而且因为类别更好,您还可以添加一个界面:

And because categories are just better, you could also add an interface:

@interface NSString (emailValidation) 
  - (BOOL)isValidEmail;
@end

实施

@implementation NSString (emailValidation)
-(BOOL)isValidEmail
{
  BOOL stricterFilter = NO; // Discussion http://blog.logichigh.com/2010/09/02/validating-an-e-mail-address/
  NSString *stricterFilterString = @"^[A-Z0-9a-z\._%+-]+@([A-Za-z0-9-]+\.)+[A-Za-z]{2,4}$";
  NSString *laxString = @"^.+@([A-Za-z0-9-]+\.)+[A-Za-z]{2}[A-Za-z]*$";
  NSString *emailRegex = stricterFilter ? stricterFilterString : laxString;
  NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
  return [emailTest evaluateWithObject:self];
}
@end

然后利用:

if([@"emailString@email.com" isValidEmail]) { /* True */ }
if([@"InvalidEmail@notreallyemailbecausenosuffix" isValidEmail]) { /* False */ }