<转>代码判断邮箱是否合法

-(BOOL)validateEmail:(NSString*)email{

if( (0 != [email rangeOfString:@"@"].length) &&  (0 != [email rangeOfString:@"."].length) )
{
NSMutableCharacterSet *invalidCharSet = [[[[NSCharacterSet alphanumericCharacterSet] invertedSet]mutableCopy]autorelease];
[invalidCharSet removeCharactersInString:@"_-"];

NSRange range1 = [email rangeOfString:@"@" options:NSCaseInsensitiveSearch];

// If username part contains any character other than "."  "_" "-"

NSString *usernamePart = [email substringToIndex:range1.location];
NSArray *stringsArray1 = [usernamePart componentsSeparatedByString:@"."];
for (NSString *string in stringsArray1) {
NSRange rangeOfInavlidChars=[string rangeOfCharacterFromSet: invalidCharSet];
if(rangeOfInavlidChars.length !=0 || [string isEqualToString:@""])
return NO;
}

NSString *domainPart = [email substringFromIndex:range1.location+1];
NSArray *stringsArray2 = [domainPart componentsSeparatedByString:@"."];

for (NSString *string in stringsArray2) {
NSRange rangeOfInavlidChars=[string rangeOfCharacterFromSet:invalidCharSet];
if(rangeOfInavlidChars.length !=0 || [string isEqualToString:@""])
return NO;
}

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