我正在与委托进行一些练习，但现在我遇到了 UIView 的问题。这是我的故事板
我想用 3 个 UISlider 改变 UIView 的颜色。UISliders 的范围是从 0 到 255。这是我的代码：
ColorField 是 UIView 自定义类
颜色字段.h
#import <UIKit/UIKit.h>
@protocol ColorFieldDelegate <NSObject>
-(NSArray *)giveMeColors;
@end
@interface ColorField : UIView
@property (nonatomic , weak) IBOutlet id<ColorFieldDelegate> delegate;
@end
颜色域.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
颜色视图控制器.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
颜色视图控制器.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
但是...这是结果：它只显示没有渐变的红色、绿色和蓝色，例如：RGB (255,0,75) is THIS
而不是这个：
我不知道它不能向我显示渐变...
谢谢！！
马可·曼佐尼