文本处理

-(int)calculateTextNumber:(NSString *) textA
{
    float number = 0.0;
    int index = 0;
    for (index; index < [textA length]; index++) {
        
        NSString *character = [textA substringWithRange:NSMakeRange(index, 1)];
        
        if ([character lengthOfBytesUsingEncoding:NSUTF8StringEncoding] == 3) {
            number++;
        } else {
            number = number+0.5;
        }
    }
    return ceil(number);
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    textField.text = [textField.text  stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    
    if ([textField.text length] > 6) {
        NSString *text = textField.text;
        textField.text = [text substringToIndex:6];
    }
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    
    if ([string isEqualToString:@" "]) {
        return NO;
    }
    
    if([textField.text length] >= 6 && range.length != 1)
        return NO;
    
    return YES;
}