CODEWITHSUNDEEP
objective-cuislider
Kaisa Koivisto
Kaisa Koivisto

Reputation: 11

UISlider values

I'm trying to create an app that has three UISlider used for selecting R, G and B values. The slider should change the colour of a label according to the sliders values.

ViewController.h

#import <UIKit/UIKit.h>

 @interface ViewController : UIViewController
{
NSInteger color;

IBOutlet UISlider *redSlider;
IBOutlet UISlider *greenSlider;
IBOutlet UISlider *blueSlider;
IBOutlet UILabel  *colorLabel;
}

@property (nonatomic, retain) UISlider *redSlider;
@property (nonatomic, retain) UISlider *greenSlider;
@property (nonatomic, retain) UISlider *blueSlider;

colorLabel.textColor = [UIColor colorWithRed: redSlider.value green:greenSlider.value
blue:blueSlider.value alpha:1];


 @end

ViewController.m

 #import "ViewController.h"

 @interface ViewController ()


 @end

 @implementation ViewController

 - (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@synthesize redSlider, greenSlider, blueSlider;




@end

This is what I have so far and I'm totally stuck.

Upvotes: 0

Views: 700

Answers (3)

Kundan
Kundan

Reputation: 3082

Your ViewController.h :-

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
{    
IBOutlet UISlider *redSlider;
IBOutlet UISlider *greenSlider;
IBOutlet UISlider *blueSlider;
IBOutlet UILabel  *colorLabel;
}

@property (nonatomic, retain) UISlider *redSlider;
@property (nonatomic, retain) UISlider *greenSlider;
@property (nonatomic, retain) UISlider *blueSlider;

 @end

and your ViewController.m will be like this:-

#import "ViewController.h"

@interface ViewController ()
 @end

@implementation ViewController
@synthesize redSlider, greenSlider, blueSlider;
 - (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self changeLabelColor];
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

-(Void) changeLabelColor
    {
colorLabel.backgroundcolor = [UIColor colorWithRed:redSlider.value green:redSlider.value blue:redSlider.value alpha:1.0];
     }
        @end

As i didn’t copied paste and i have written it, there might be some typo.. textcolor wouldn’t change label color so i changed it to backgroundcolor. you can also add slider method with IBAction.

Upvotes: 0

Fogmeister
Fogmeister

Reputation: 77631

You can do this like...

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@end

ViewController.m

#import "ViewController.h"

@interface ViewController ()

// you need to make sure these are actually created
// and give them all a target of self and action sliderValueChanged
@property (nonatomic, retain) UISlider *redSlider;
@property (nonatomic, retain) UISlider *greenSlider;
@property (nonatomic, retain) UISlider *blueSlider;

// not sure where this is set up
@property (nonatomic, strong) UILabel *colorLabel;

@end

@implementation ViewController

 - (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    // You may have to create your labels and sliders in here...
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)sliderValueChanged
{
    // the sliders have changed so set the colour of the label
    // based on the new values of the sliders.
    self.colorLabel.textColor = [UIColor colorWithRed:self.redSlider.value
                                                green:self.greenSlider.value
                                                 blue:self.blueSlider.value
                                                alpha:1.0];
}

@end

Upvotes: 3

Popeye
Popeye

Reputation: 12093

Because you don't actually have a question I'm going to take a guess that your code doesn't compile, because it wouldn't.

colorLabel.textColor = [UIColor colorWithRed: redSlider.value green:greenSlider.value blue:blueSlider.value alpha:1];

The above line doesn't belong in you interface. I would recommend you change the code you currently have to something like.

ViewController.h

@interface ViewController : UIViewController

// You don't need the ivars anymore these get generated with the properties below  

@property (nonatomic, retain) IBOutlet UISlider *redSlider;
@property (nonatomic, retain) IBOutlet UISlider *greenSlider;
@property (nonatomic, retain) IBOutlet UISlider *blueSlider;
@property (nonatomic, retain) IBOutlet UILabel *colorLabel
@property (assign) NSInteger color;

@end

ViewController.m

@implementation ViewController

// Also no need for the synthesize as these also get generated automatically

- (void)viewDidLoad
{
    [super viewDidLoad];
    // To change the actual color when changing the value of a slider move this to a method that gets called on slider changed.
    colorLabel.textColor = [UIColor colorWithRed:self.redSlider.value green:self.greenSlider.value self.blue:blueSlider.value alpha:1];
}

@end

And once you actually ask a question I might also be able to help you with that.

Upvotes: 1

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