[iOS开发]-判断是否合法邮箱

方法一:直接使用cocoa库中NSString的各个属性来处理判断。

此方法来源:http://www.devdiv.com/home.php?mod=space&uid=8639&do=blog&id=4090

//判断邮箱是否合法的代码
-(BOOL)validateEmail:(NSString*)email
{
if((0 != [email rangeOfString:@"@"].length) &&
(0 != [email rangeOfString:@"."].length))
{

NSCharacterSet* tmpInvalidCharSet = [[NSCharacterSet alphanumericCharacterSet] invertedSet];
NSMutableCharacterSet* tmpInvalidMutableCharSet = [[tmpInvalidCharSet mutableCopy] autorelease];
[tmpInvalidMutableCharSet removeCharactersInString:@"_-"];

//使用compare option 来设定比较规则，如
//NSCaseInsensitiveSearch是不区分大小写
//NSLiteralSearch 进行完全比较,区分大小写
//NSNumericSearch 只比较定符串的个数，而不比较字符串的字面值
NSRange range1 = [email rangeOfString:@"@"
options:NSCaseInsensitiveSearch];

//取得用户名部分
NSString* userNameString = [email substringToIndex:range1.location];
NSArray* userNameArray   = [userNameString componentsSeparatedByString:@"."];

for(NSString* string in userNameArray)
{
NSRange rangeOfInavlidChars = [string rangeOfCharacterFromSet: tmpInvalidMutableCharSet];
if(rangeOfInavlidChars.length != 0 || [string isEqualToString:@""])
return NO;
}

NSString *domainString = [email substringFromIndex:range1.location+1];
NSArray *domainArray   = [domainString componentsSeparatedByString:@"."];

for(NSString *string in domainArray)
{
NSRange rangeOfInavlidChars=[string rangeOfCharacterFromSet:tmpInvalidMutableCharSet];
if(rangeOfInavlidChars.length !=0 || [string isEqualToString:@""])
return NO;
}

return YES;
}
else // no ''@'' or ''.'' present
return NO;
}

BOOL NSStringIsValidEmail(NSString *checkString)
{
NString *stricterFilterString = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
NSString *laxString = @".+@.+\.[A-Za-z]{2}[A-Za-z]*";
NSString *emailRegex = stricterFilter ? stricterFilterString : laxString;
NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
return [emailTest evaluateWithObject:checkString];
}

方法二：使用第三方类RegexKitLite

RegexKitLite应该说是ios开发必备第三方类库，因为它几经完美的实现了所以正则处理：

BOOL isEmailType = [noString isMatchedByRegex:@"\\b([a-zA-Z0-9%_.+\\-]+)@([a-zA-Z0-9.\\-]+?\\.[a-zA-Z]{2,6})\\b"];