问题...我有一串允许的字符"0123456789".如何从键盘中允许退格...当我从下面实现代码时...退格键不再有效......我该如何解决这个问题？
- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSCharacterSet *nonNumberSet = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789."] invertedSet];
return ([string stringByTrimmingCharactersInSet:nonNumberSet].length > 0);
}