通过cagradientLayer类封装uiimageview动画色度差

#import <UIKit/UIKit.h>

typedef NS_ENUM(NSInteger, EcolorDirectionType)

{

    EcolorDirectionUp,    //上

    EcolorDirectionDown,  //下

    EcolorDirectionRight, //右

    EcolorDirectionLeft,  //左

};

@interface ColorImageView : UIImageView



/**

 *  @brief 确定方向

 */

@property(nonatomic,assign) EcolorDirectionType direction;



/**

 *  @brief  颜色

 */

@property(nonatomic,strong) UIColor *color;



/**

 *  @brief  百分比

 */

@property(nonatomic,assign) CGFloat percent;



@end

#import "ColorImageView.h"

@interface ColorImageView ()

{

    CAGradientLayer *_gradientLayer;

}

@end

@implementation ColorImageView

@synthesize color     = _color;

@synthesize percent   = _percent;

@synthesize direction = _direction;



- (instancetype)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self)

    {

        _gradientLayer = [CAGradientLayer layer];

        _gradientLayer.frame = self.bounds;

        _gradientLayer.borderWidth = 1.0f;

        _gradientLayer.colors = @[ (__bridge id)[UIColor clearColor].CGColor,

                                   (__bridge id)[UIColor redColor].CGColor

                                  ];

        _gradientLayer.locations = @[@(0.1),@(1)];

        

        [self.layer addSublayer:_gradientLayer];

    }

    return self;

}

/**

 *  @brief  设置颜色

 *  @param color 重写setter方法

 */

- (void)setColor:(UIColor *)color

{

    _color = color;

    _gradientLayer.colors = @[ (__bridge id)[UIColor clearColor].CGColor,

                               (__bridge id)color.CGColor

                               ];

}

- (UIColor *)color

{

    return _color;

}

/**

 *  @brief  设置颜色分割点

 *  @param percent 重写setter方法

 */

- (void)setPercent:(CGFloat)percent

{

    _percent = percent;

    _gradientLayer.locations= @[@(percent),@(1)];

}



-(CGFloat)percent

{

    return _percent;

}



/**

 *  @brief  设置颜色渐变方向

 *  @param direction 重写setter方法

 */

-(void)setDirection:(EcolorDirectionType)direction

{

    _direction=direction;

    switch (direction) {

        case EcolorDirectionUp:

        {

            _gradientLayer.startPoint = CGPointMake(0, 0);

            _gradientLayer.endPoint   = CGPointMake(0, 1);

        }

            break;

        case EcolorDirectionDown:

        {

            _gradientLayer.startPoint = CGPointMake(0, 1);

            _gradientLayer.endPoint   = CGPointMake(0, 0);



        }

            break;

        case EcolorDirectionLeft:

        {

            _gradientLayer.startPoint = CGPointMake(0, 0);

            _gradientLayer.endPoint   = CGPointMake(1, 0);



        }

            break;

        case EcolorDirectionRight:

        {

            _gradientLayer.startPoint = CGPointMake(1, 0);

            _gradientLayer.endPoint   = CGPointMake(0, 0);

        }

            break;

        default:

        {

            _gradientLayer.startPoint = CGPointMake(0, 0);

            _gradientLayer.endPoint   = CGPointMake(0, 1);

        }

            break;

    }

}

-(EcolorDirectionType)direction

{

    return _direction;

}

@end

#import "ViewController.h"

#import "ColorImageView.h"

@interface ViewController ()

{



    ColorImageView *_imvColor;

}

@end



@implementation ViewController



- (void)viewDidLoad

{

    [super viewDidLoad];



    _imvColor=[[ColorImageView alloc]initWithFrame:CGRectMake(0, 0, 220, 185)];

    _imvColor.image = [UIImage imageNamed:@"1"];

    _imvColor.center = self.view.center;

    

    [self.view addSubview:_imvColor];

    [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(event) userInfo:nil repeats:YES];

   // [self performSelector:@selector(event) withObject:nil afterDelay:2.0f];



}

- (void)event

{

    _imvColor.direction=EcolorDirectionUp;

    _imvColor.color=[UIColor cyanColor];

    _imvColor.percent=arc4random()%100/100.f;

}

@end