@property (weak, nonatomic) UITextField *bankCardNumber;
self.bankCardNumber.delegate = self;
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if (textField == self.bankCardNumber) {
// 4位分隔银行卡卡号
NSString *text = [textField text];
NSCharacterSet *characterSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789\b"];
string = [string stringByReplacingOccurrencesOfString:@" " withString:@""];
if ([string rangeOfCharacterFromSet:[characterSet invertedSet]].location != NSNotFound) {
return NO;
}
text = [text stringByReplacingCharactersInRange:range withString:string];
text = [text stringByReplacingOccurrencesOfString:@" " withString:@""];
NSString *newString = @"";
while (text.length > 0) {
NSString *subString = [text substringToIndex:MIN(text.length, 4)];
newString = [newString stringByAppendingString:subString];
if (subString.length == 4) {
newString = [newString stringByAppendingString:@" "];
}
text = [text substringFromIndex:MIN(text.length, 4)];
}
newString = [newString stringByTrimmingCharactersInSet:[characterSet invertedSet]];
if ([newString stringByReplacingOccurrencesOfString:@" " withString:@""].length >= 21) {
return NO;
}
[textField setText:newString];
return NO;
}
return YES;
}
