Objective c 验证iphone中UITextField中的电子邮件地址

可能重复：

我有一个

UITextField

，其中我从他们输入的用户那里获取电子邮件地址，我想验证该电子邮件地址，比如我希望它应该检查它是否包含@符号和其他电子邮件字符等符号

如果电子邮件地址中有错误，则应显示一个

UIAlertView

，该视图将显示“输入有效的电子邮件地址”。

添加到项目中并找到以下解决方案

---

您可以使用NSPredicate执行此操作

//suppose emailID is your entered email address NSString
NSString *emailFormat1 = @"[A-Z0-9a-z._]+@[A-Za-z0-9]+\\.[A-Za-z]{2,4}";     


NSPredicate *emailTest1 = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailFormat1]; 


if ([emailTest1 evaluateWithObject:emailID]||[emailTest2 evaluateWithObject:emailID]) {
   //yes it is valid
}
else
    //no it is invalid

---

客观C风格

NSString *emailRegEx = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,10}";
NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegEx];

if ([emailTest evaluateWithObject:email.text] == NO) {

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Test!" message:@"Please Enter Valid Email Address." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
    [alert release];

    return;
}

快速风格

class func isValidEmail(emailString:String) -> Bool {

    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,10}"
    var emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)

    let result = emailTest?.evaluateWithObject(emailString)
    return result!
}