你可以创建一个自定义类GradientView:

斯威夫特5

class GradientView: UIView {
    override open class var layerClass: AnyClass {
       return CAGradientLayer.classForCoder()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        let gradientLayer = layer as! CAGradientLayer
        gradientLayer.colors = [UIColor.white.cgColor, UIColor.black.cgColor]
    }
}

在故事板中，将类类型设置为你想要有渐变背景的任何视图:

这在以下方面是更好的:

不需要设置框架的克莱尔 像往常一样在UIView上使用NSConstraint 不需要创建子层(更少的内存使用)

因为我只需要一种类型的梯度在我的应用程序，我创建了一个子类的UIView和预配置梯度层初始化固定的颜色。 UIView的初始化器调用configuregradientlayer -方法，它配置CAGradientLayer:

DDGradientView.h:

#import <UIKit/UIKit.h>

@interface DDGradientView : UIView {

}
@end

DDGradientView.m:

#import "DDGradientView.h"

@implementation DDGradientView

// Change the views layer class to CAGradientLayer class
+ (Class)layerClass
{
    return [CAGradientLayer class];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if(self) {
        [self configureGradientLayer];
    }
    return self;
}

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if(self) {
        [self configureGradientLayer];
    }
    return self;
}

// Make custom configuration of your gradient here   
- (void)configureGradientLayer {
    CAGradientLayer *gLayer = (CAGradientLayer *)self.layer;
    gLayer.colors = [NSArray arrayWithObjects:(id)[[UIColor whiteColor] CGColor], (id)[[UIColor lightGrayColor] CGColor], nil];
}
@end

我的解决方案是创建具有CAGradientLayer可访问的UIView子类作为只读属性。这将允许你自定义你想要的渐变，你不需要自己处理布局变化。子类实现:

@interface GradientView : UIView

@property (nonatomic, readonly) CAGradientLayer *gradientLayer;

@end

@implementation GradientView

+ (Class)layerClass
{
    return [CAGradientLayer class];
}

- (CAGradientLayer *)gradientLayer
{
    return (CAGradientLayer *)self.layer;
}

@end

用法:

self.iconBackground = [GradientView new];
[self.background addSubview:self.iconBackground];
self.iconBackground.gradientLayer.colors = @[(id)[UIColor blackColor].CGColor, (id)[UIColor whiteColor].CGColor];
self.iconBackground.gradientLayer.startPoint = CGPointMake(1.0f, 1.0f);
self.iconBackground.gradientLayer.endPoint = CGPointMake(0.0f, 0.0f);

试试这个对我来说很有魔力，

Objective - C

我已经设置了RGB渐变背景颜色为UIview

   UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0,0,320,35)];
   CAGradientLayer *gradient = [CAGradientLayer layer];
   gradient.frame = view.bounds;
   gradient.startPoint = CGPointZero;
   gradient.endPoint = CGPointMake(1, 1);
   gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor colorWithRed:34.0/255.0 green:211/255.0 blue:198/255.0 alpha:1.0] CGColor],(id)[[UIColor colorWithRed:145/255.0 green:72.0/255.0 blue:203/255.0 alpha:1.0] CGColor], nil];
   [view.layer addSublayer:gradient];

更新: Swift3 +

代码:

 var gradientView = UIView(frame: CGRect(x: 0, y: 0, width: 320, height: 35))
 let gradientLayer:CAGradientLayer = CAGradientLayer()
 gradientLayer.frame.size = self.gradientView.frame.size
 gradientLayer.colors = 
 [UIColor.white.cgColor,UIColor.red.withAlphaComponent(1).cgColor] 
//Use diffrent colors
 gradientView.layer.addSublayer(gradientLayer)

你可以添加渐变颜色的起点和终点。

  gradientLayer.startPoint = CGPoint(x: 0.0, y: 1.0)
  gradientLayer.endPoint = CGPoint(x: 1.0, y: 1.0)

更多细节请参考CAGradientLayer文档

希望这对一些人有所帮助。

这是我推荐的方法。

为了提高可重用性，我建议创建一个CAGradientLayer类别，并添加所需的渐变作为类方法。在头文件中像这样指定它们:

#import <QuartzCore/QuartzCore.h>

@interface CAGradientLayer (SJSGradients)

+ (CAGradientLayer *)redGradientLayer;
+ (CAGradientLayer *)blueGradientLayer;
+ (CAGradientLayer *)turquoiseGradientLayer;
+ (CAGradientLayer *)flavescentGradientLayer;
+ (CAGradientLayer *)whiteGradientLayer;
+ (CAGradientLayer *)chocolateGradientLayer;
+ (CAGradientLayer *)tangerineGradientLayer;
+ (CAGradientLayer *)pastelBlueGradientLayer;
+ (CAGradientLayer *)yellowGradientLayer;
+ (CAGradientLayer *)purpleGradientLayer;
+ (CAGradientLayer *)greenGradientLayer;

@end

然后在你的实现文件中，用下面的语法指定每个渐变:

+ (CAGradientLayer *)flavescentGradientLayer
{
    UIColor *topColor = [UIColor colorWithRed:1 green:0.92 blue:0.56 alpha:1];
    UIColor *bottomColor = [UIColor colorWithRed:0.18 green:0.18 blue:0.18 alpha:1];

    NSArray *gradientColors = [NSArray arrayWithObjects:(id)topColor.CGColor, (id)bottomColor.CGColor, nil];
    NSArray *gradientLocations = [NSArray arrayWithObjects:[NSNumber numberWithInt:0.0],[NSNumber numberWithInt:1.0], nil];

    CAGradientLayer *gradientLayer = [CAGradientLayer layer];
    gradientLayer.colors = gradientColors;
    gradientLayer.locations = gradientLocations;

    return gradientLayer;
}

然后简单地将这个类别导入你的ViewController或任何其他所需的子类，并像这样使用它:

CAGradientLayer *backgroundLayer = [CAGradientLayer purpleGradientLayer];
backgroundLayer.frame = self.view.frame;
[self.view.layer insertSublayer:backgroundLayer atIndex:0];

在Swift 3.1中 我已经添加了这个扩展到UIView

import Foundation
import UIKit
import CoreGraphics


extension UIView {
    func gradientOfView(withColours: UIColor...) {

        var cgColours = [CGColor]()

        for colour in withColours {
            cgColours.append(colour.cgColor)
        }
        let grad = CAGradientLayer()
        grad.frame = self.bounds
        grad.colors = cgColours
        self.layer.insertSublayer(grad, at: 0)
    }
}

然后我用它来调用

    class OverviewVC: UIViewController {

        override func viewDidLoad() {
            super.viewDidLoad()

            self.view.gradientOfView(withColours: UIColor.red,UIColor.green, UIColor.blue)

        }
}