#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@end

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

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

    //UIView

    UIView *view=[[UIView alloc]initWithFrame:CGRectMake(10, 100, 200, 200)];

    view.backgroundColor=[UIColor redColor];

    [self.view addSubview:view];

    //淡出

    //[self fadeOut:view];

    //淡入

    //[self fadeIn:view];

}

//淡出

-(void) fadeOut:(UIView *)view

{

    CGContextRef context = UIGraphicsGetCurrentContext();

    [UIView beginAnimations:nil context:context];

    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];

    [UIView setAnimationDuration:0.3];

    [view setAlpha:0.0f];

    [UIView commitAnimations];

}

//淡入

-(void) fadeIn:(UIView *)view

{

    CGContextRef context = UIGraphicsGetCurrentContext();

    [UIView beginAnimations:nil context:context];

    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];

    [UIView setAnimationDuration:0.3];

    [view setAlpha:1.0f];

    [UIView commitAnimations];

}

- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}