Question

So, I have the slider adding UITextFields but it’s not updating/subtracting UITextField’s when selecting less than the previous Slider Value. Does [self.view addSubview:textField]; need to be outside of the for loop? Thanks in advance.

- (IBAction) sliderValueChanged:(UISlider *)sender {
float senderValue = [sender value];
int roundedValue = senderValue * 1;
ingredientLabel.text = [NSString stringWithFormat:@"%d", roundedValue];
int moveYBy = 35;
int baseY = 140;
for(int y = 0; y < roundedValue; y++){
    UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(20, baseY, 227, 31)];
    textField.text = [NSString stringWithFormat:@"%d", roundedValue];
    textField.borderStyle = UITextBorderStyleRoundedRect;
    baseY = baseY + moveYBy;
    [self.view addSubview:textField];
    [textField release];
    NSLog(@"Adding %d fields!", roundedValue);
}
NSLog(@"%d", roundedValue);
}

Answer 1

You are creating N text fields everytime the slider value changes (where n is the rounded value).

Instead, you should make an NSMutableArray an iVar and store all the text fields there, when roundedValue is bigger than the number of text fields in that array, we add more. When it’s smaller, we remove some.

(I’m using an iVar called textFieldsArray, and I also changed a little the way the y is calculated for the arrays)

- (IBAction) sliderValueChanged:(UISlider *)sender {
    float senderValue = [sender value];
    int roundedValue = senderValue * 1;
    ingredientLabel.text = [NSString stringWithFormat:@"%d", roundedValue];
    for(int y = 0; y < roundedValue; y++){
        if(y > [textFieldsArray count]){
            UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(20, 140 + 35 * y, 227, 31)];
            textField.text = [NSString stringWithFormat:@"%d", roundedValue];
            textField.borderStyle = UITextBorderStyleRoundedRect;
            [self.view addSubview:textField];
            [textFieldsArray addObject:textField];
            [textField release];
            NSLog(@"Adding %d fields!", roundedValue);
        }
    }
    while([textFieldsArray count] > roundedValue){
        UITextField *textField = [textFieldsArray lastObject];
        [textField removeFromSuperview];
        [textFieldsArray removeLastObject];
    }
    NSLog(@"%d", roundedValue);
}