1.帶有小數點的數字輸入框限制

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    CGFloat maxNumber = 6666.66;
    NSString *validStr = nil;
    NSUInteger nDotLoc = [textField.text rangeOfString:@"."].location;
    if (NSNotFound == nDotLoc && 0
 
 != range.location) {

        validStr = @"0123456789.\n";
    } else {

        validStr = @"0123456789\n";
    }
    NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:validStr] invertedSet];
    NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""
 
];

    if (![string isEqualToString:filtered]) {

        return NO;
    }

    if (NSNotFound != nDotLoc && range.location > nDotLoc + 2) {

        return NO;
    }



    NSString *num = [NSString stringWithFormat:@"%@%@",textField.text,string];

    if (num.floatValue > maxNumber) {

        if
 
 (![string isEqualToString:@""]) {

            return NO;
        }
    }

    return YES;
}

2.處理鍵盤上方聯想輸入

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(textFiledEditChanged:) name:UITextFieldTextDidChangeNotification object:inputTextField];

- (void)textFiledEditChanged:(NSNotification *)obj {

    //限制條件
    NSInteger length = 10;
    UITextField *textField = (UITextField *)obj.object;
    NSString *language = [[UIApplication sharedApplication]textInputMode].primaryLanguage;
    if ([language isEqualToString:@"zh-Hans"]) {

        UITextRange *selectedRange = [textField markedTextRange];
        UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:0];
        if (!position) {

            if (textField.text.length > length) {

                textField.text = [textField.text substringToIndex:length];
            }
        }
    } else {

        if (textField.text.length > length) {

            textField.text = [textField.text substringToIndex:length];
        }
    }
}