ios开发实现UIView背景颜色渐变

http://blog.sina.com.cn/s/blog_877e9c3c0101hx6x.html

效果图




#import"ACViewController.h"

@interface ACViewController()

@end

@implementationACViewController

- (void)viewDidLoad
{

    

   [superviewDidLoad];

// Do any additional setup after loading the view, typically from anib.

    

    

  
//三种方法实现颜色渐变，效果一样

   self.view.backgroundColor=[UIColor
blackColor];
   CGFloat a1=1.0;

   //第一种方法
   for (double i=0; i<<span style="color:#0433ff">460; i++) {
       a1=(i/460);

       
      UIView*view1=[[UIView
alloc]initWithFrame:CGRectMake(0.0, i,
110.0, 1)];
       view1.backgroundColor=[UIColor
colorWithRed:1.0
green:a1 blue:a1
alpha:1.0];
       [self.view
addSubview:view1];
       [view1
release];
    }

   //第二种方法
   for (double i=0; i<<span style="color:#0433ff">460; i++) {
       a1=1-(i/460);

       
      UIView*view1=[[UIView
alloc]initWithFrame:CGRectMake(110.0, i,
105.0, 1)];
       view1.backgroundColor=[UIColor
colorWithRed:0.0
green:a1 blue:0.0
alpha:1.0];
       [self.view
addSubview:view1];
       [view1
release];
    }

   //第三种方法
   for (double i=0; i<<span style="color:#0433ff">460; i++) {
       a1=(i/460);

       
      UIView*view1=[[UIView
alloc]initWithFrame:CGRectMake(215.0, i,
105.0, 1)];
       view1.backgroundColor=[UIColor
colorWithRed:0.0
green:0.0
blue:1.0 alpha:a1];
       [self.view
addSubview:view1];
       [view1
release];
    }

 
}

- (void)didReceiveMemoryWarning
{

   [superdidReceiveMemoryWarning];

   // Dispose of any resources that can berecreated.
}

@end