IOS实现图片倒影效果

#import <QuartzCore/QuartzCore.h>
- (void)viewDidLoad
{
[super viewDidLoad];

[[[self view] layer] setBackgroundColor:[[UIColor blackColor] CGColor]];

UIImage *balloon = [UIImage imageNamed:@"app3.png"];

//图片层

CALayer *topLayer = [[CALayer alloc] init];

[topLayer setBounds:CGRectMake(0.0f, 0.0f, 320-100.0, 240-100)];

[topLayer setPosition:CGPointMake(160.0f, 120.0f)];

[topLayer setContents:(id)[balloon CGImage]];

[[[self view] layer] addSublayer:topLayer];

//图片阴影层

CALayer *reflectionLayer = [[CALayer alloc] init];

[reflectionLayer setBounds:CGRectMake(0.0f, 0.0f, 320.0-100, 240.0-100)];

[reflectionLayer setPosition:CGPointMake(160.0f, 310.0f-100)];

[reflectionLayer setContents:[topLayer contents]];

[reflectionLayer setValue:[NSNumber numberWithFloat:180.0] forKeyPath:@"transform.rotation.x"];

//渐变层

CAGradientLayer *gradientLayer = [[CAGradientLayer alloc] init];

[gradientLayer setBounds:[reflectionLayer bounds]];

[gradientLayer setPosition:CGPointMake([reflectionLayer bounds].size.width/2, [reflectionLayer bounds].size.height/2)];

[gradientLayer setColors:[NSArray arrayWithObjects: (id)[[UIColor clearColor] CGColor],(id)[[UIColor blackColor] CGColor], nil]];

[gradientLayer setStartPoint:CGPointMake(0.5,0.35)];

[gradientLayer setEndPoint:CGPointMake(0.5,1.0)];

[reflectionLayer setMask:gradientLayer];

[[[self view] layer] addSublayer:reflectionLayer];
// Do any additional setup after loading the view, typically from a nib.
}