Change UIView's background color - iphone

Question

I am doing some exercises with delegate, but now I have a problem with a UIView. This is my storyboard
I want to change the color of the UIView with 3 UISliders. The range of UISliders is from 0 to 255.
And this is my code:
ColorField is the UIView custom class
ColorField.h
#import <UIKit/UIKit.h>
#protocol ColorFieldDelegate <NSObject>
-(NSArray *)giveMeColors;
#end
#interface ColorField : UIView
#property (nonatomic , weak) IBOutlet id<ColorFieldDelegate> delegate;
#end
ColorField.m
#import "ColorField.h"
#implementation ColorField
#synthesize delegate = _delegate;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
NSArray *arrayOfColors = [self.delegate giveMeColors];
int red = [[arrayOfColors objectAtIndex:0] intValue];
int green = [[arrayOfColors objectAtIndex:1] intValue];
int blue = [[arrayOfColors objectAtIndex:2] intValue];
NSLog(#"Red --> %d" ,red);
NSLog(#"Green --> %d" ,green);
NSLog(#"Blue --> %d \n\n" ,blue);
self.backgroundColor = [UIColor colorWithRed:red green:green blue:blue alpha:1.0];
}
#end
ColorViewController.h
#import <UIKit/UIKit.h>
#import "ColorField.h"
#interface ColorViewController : UIViewController <ColorFieldDelegate>
#property (nonatomic) IBOutlet ColorField *colorField;
#property (weak, nonatomic) IBOutlet UISlider *redSlider;
#property (weak, nonatomic) IBOutlet UISlider *greenSlider;
#property (weak, nonatomic) IBOutlet UISlider *blueSlider;
#end
ColorViewController.m
#import "ColorViewController.h"
#interface ColorViewController ()
#property (nonatomic) double redQuantity;
#property (nonatomic) double greenQuantity;
#property (nonatomic) double blueQuantity;
#end
#implementation ColorViewController
#synthesize colorField = _colorField;
#synthesize redSlider;
#synthesize greenSlider;
#synthesize blueSlider;
#synthesize redQuantity;
#synthesize blueQuantity;
#synthesize greenQuantity;
- (void)viewDidLoad
{
[super viewDidLoad];
[self.colorField setDelegate:self];
[self.colorField setNeedsDisplay];
self.redQuantity = 125.0;
self.blueQuantity = 125.0;
self.greenQuantity = 125.0;
[self.colorField setNeedsDisplay];
// Do any additional setup after loading the view, typically from a nib.
}
-(ColorField *)colorField
{
if (_colorField == nil) {
_colorField = [[ColorField alloc] init];
}
return _colorField;
}
- (void)viewDidUnload
{
[self setColorField:nil];
[self setRedSlider:nil];
[self setGreenSlider:nil];
[self setBlueSlider:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
-(IBAction)changeRedQuantity:(UISlider *)sender
{
//methods of UISliders
self.redQuantity = [sender value];
[self.colorField setNeedsDisplay];
}
-(IBAction)changeBlueQuantity:(UISlider *)sender
{
self.blueQuantity = [sender value];
[self.colorField setNeedsDisplay];
}
-(IBAction)changeGreenQuantity:(UISlider *)sender
{
self.greenQuantity = [sender value];
[self.colorField setNeedsDisplay];
}
-(NSArray *)giveMeColors
{
NSNumber *redNumber = [NSNumber numberWithDouble:self.redQuantity];
NSNumber *greenNumber = [NSNumber numberWithDouble:self.greenQuantity];
NSNumber *blueNumber = [NSNumber numberWithDouble:self.blueQuantity];
NSArray *array = [[NSArray alloc] initWithObjects:redNumber, greenNumber,blueNumber, nil];
return array;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
#end
BUT...this is the result: It show me only RED, GREEN and BLUE colors without gradation, for example: RGB (255,0,75) is THIS
and not THIS:
I don't know with it can't show me gradation...
Thanks!!
Marco Manzoni

Answer 1

You have to divide your slidervalues by 255.0.
[UIColor colorWithRed:red/255.0 green:green/255.0 blue:blue/255.0 alpha:1.0];
colorWithRed only accepts values 0.0-1.0