Question

I’m trying to get a UISlider into my UIToolbar and to take the value from it and process it. I also want to be able to change the slider.value via other methods.
So, I set it up for the UISlider by it’s self (not on a UIToolBar) and everything worked fine. Then, when I put it into the UIToolBar, the value stopped getting sent to and from it (I am NSLogging it whenever it changes and I keep getting 0 returned to me).
Here’s the relevant section of my code – does anybody have any ideas?

- (void)setupToolBarAndSlider {
    CGRect frame = CGRectMake(0.0, 0.0, 200.0, 30.0);
    UISlider *slider = [[UISlider alloc] initWithFrame:frame];
    [slider addTarget:self action:@selector(sliderValueChanged) forControlEvents:UIControlEventValueChanged];
    [slider setBackgroundColor:[UIColor clearColor]];
    slider.minimumValue = 0;
    slider.maximumValue = 8;
    slider.continuous = YES;
    slider.value = questionNumberForArray;
    //Change slider for UIToolbar
    UIBarButtonItem *skipQuestionSlider = [[UIBarButtonItem alloc] initWithCustomView:slider];
    // Set the width of aSlider
    [skipQuestionSlider setWidth:400.0];
    //Set up UIToolBar with Slider in it.
    UIToolbar *toolBar;
    CGRect rect2 = CGRectMake(0, toolBar.frame.origin.y , self.view.frame.size.width , 44);
    toolBar = [[UIToolbar alloc]initWithFrame:rect2];
    toolBar.barStyle = UIBarStyleBlackTranslucent;
    [toolBar setItems:[NSArray arrayWithObjects:skipQuestionSlider, nil]];
    [self.view addSubview:toolBar];
}
- (void)sliderValueChanged {
    NSInteger roundedSliderNumber = round(skipQuestionSlider.value);
    NSLog(@"Slider Value = %d", roundedSliderNumber);
} 

Sam

Answer 1

A UIBarButtonItem (in your case, skipQuestionSlider) does not have a value property, it just houses the item. You need to reference the item you put in the UIBarButtonItem.

NSInteger roundedSliderNumber = round(slider.value);