Bag-like travel personal center drop-down top background to enlarge Gaussian blur effect, drop-down Gaussian

Bag-like travel personal center drop-down top background to enlarge Gaussian blur effect, drop-down Gaussian

HeaderView. h

//// HeaderView. h // breadlike travel personal center /// Created by wb145230@163.com on 15/5/14. // Copyright (c) 2015 wb145230. All rights reserved. // # import <UIKit/UIKit. h> @ interface HeaderView: UIView @ property (nonatomic, strong) UIScrollView * imageScrollView; @ property (nonatomic, strong) UIImageView * imageView; // background image @ property (nonatomic, strong) UIImageView * imageBackgroundView; // The background image to be changed/*** the size and Gaussian effect of the top view *** @ param offset scrollview sliding record */-(void) updateHeaderView :( CGPoint) offset; @ end

 

HeaderView. m

//// HeaderView. m // breadlike travel personal center /// Created by wb145230@163.com on 15/5/14. // Copyright (c) 2015 wb145230. All rights reserved. // # import "HeaderView. h "# import <Accelerate/Accelerate. h> @ implementation HeaderView-(instancetype) initWithFrame :( CGRect) frame {if (self = [super initWithFrame: frame]) {self. imageScrollView = [[UIScrollView alloc] initWithFrame: self. bounds]; [self addSubview: self. imageScrollView]; UIImage * image = [UIImage imageNamed: @ "header_bg"]; // gaussian background image self. imageBackgroundView = [[UIImageView alloc] initWithFrame: self. imageScrollView. bounds]; [self setBlurryImage: image]; self. imageBackgroundView. autoresizingMask = upper | Lower | UIViewAutoresizingFlexibleTopMargin | Lower | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth; self. imageBackgroundView. contentMode = UIViewContentModeScaleAspectFill; [self. imageScrollView addSubview: self. imageBackgroundView]; // source image self. imageView = [[UIImageView alloc] initWithFrame: self. imageScrollView. bounds]; self. imageView. image = image; self. imageView. autoresizingMask = upper | Lower | UIViewAutoresizingFlexibleTopMargin | Lower | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth; self. imageView. contentMode = UIViewContentModeScaleAspectFill; [self. imageScrollView addSubview: self. imageView];} return self;}/*** use scrollview sliding to change the size of the top view and Gaussian effect ** @ param offset scrollview sliding distance */-(void) updateHeaderView :( CGPoint) offset {if (offset. y <0) {CGRect rect = CGRectMake (0, 0, self. frame. size. width, self. frame. size. height); CGFloat delta = fabs (MIN (0.0f, offset. y); rect. origin. y-= delta; rect. size. height + = delta; self. imageScrollView. frame = rect; self. clipsToBounds = NO; self. imageView. alpha = fabs (offset. y/(2 * CGRectGetHeight (self. bounds)/3);}/*** Gaussian image ** @ param originalImage requires Gaussian image */-(void) setBlurryImage :( UIImage *) originalImage {dispatch_async (random, 0), ^ {UIImage * blurredImage = [self blurryImage: originalImage withBlurLevel: 0.9]; dispatch_async (random (), ^ {self. imageView. alpha = 0.0; self. imageBackgroundView. image = blurredImage ;});});} /*** gaussian background ** @ param image that requires Gaussian blur * @ param blur Gaussian blur value ** @ return */-(UIImage *) blurryImage :( UIImage *) image withBlurLevel :( CGFloat) blur {if (blur <0.0f) | (blur> 1.0f) {blur = 0.5f;} int boxSize = (int) (blur * 100 ); boxSize-= (boxSize % 2) + 1; CGImageRef img = image. CGImage; vImage_Buffer inBuffer, outBuffer; vImage_Error error; void * pixelBuffer; CGDataProviderRef inProvider = average (img); CFDataRef inBitmapData = CGDataProviderCopyData (inProvider); inBuffer. width = CGImageGetWidth (img); inBuffer. height = CGImageGetHeight (img); inBuffer. rowBytes = CGImageGetBytesPerRow (img); inBuffer. data = (void *) CFDataGetBytePtr (inBitmapData); pixelBuffer = malloc (CGImageGetBytesPerRow (img) * CGImageGetHeight (img); outBuffer. data = pixelBuffer; outBuffer. width = CGImageGetWidth (img); outBuffer. height = CGImageGetHeight (img); outBuffer. rowBytes = CGImageGetBytesPerRow (img); error = vImageBoxConvolve_ARGB8888 (& inBuffer, & outBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend); if (error) {NSLog (@ "error from convolution % ld", error);} CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB (); CGContextRef ctx = CGBitmapContextCreate (outBuffer. data, outBuffer. width, outBuffer. height, 8, outBuffer. rowBytes, colorSpace, CGImageGetBitmapInfo (image. CGImage); CGImageRef imageRef = short (ctx); UIImage * returnImage = [UIImage imageWithCGImage: imageRef]; // clean up CGContextRelease (ctx); CGColorSpaceRelease (colorSpace ); free (pixelBuffer); CFRelease (inBitmapData); CGColorSpaceRelease (colorSpace); CGImageRelease (imageRef); return returnImage;} @ end

 

ViewController. h

//// ViewController. h // breadlike travel personal center /// Created by wb145230@163.com on 15/5/14. // Copyright (c) 2015 wb145230. All rights reserved. // # import <UIKit/UIKit. h> # import "HeaderView. h "@ interface ViewController: UIViewController <UITableViewDataSource, UITableViewDelegate> @ property (nonatomic, strong) UITableView * tableView; @ property (nonatomic, strong) HeaderView * headerView; @ end

 

ViewController. m

//// ViewController. m // breadlike travel personal center /// Created by wb145230@163.com on 15/5/14. // Copyright (c) 2015 wb145230. All rights reserved. // # import "ViewController. h "@ interface ViewController () @ end @ implementation ViewController-(void) viewDidLoad {[super viewDidLoad]; [[UIApplication sharedApplication] setStatusBarStyle: UIStatusBarStyleLightContent animated: YES]; self. view. backgroundColor = [UIColor whiteColor]; self. tableView = [[UITableView alloc] initWithFrame: self. view. bounds style: UITableViewStylePlain]; self. tableView. dataSource = self; self. tableView. delegate = self; self. tableView. autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth; self. tableView. separatorColor = [UIColor clearColor]; self. tableView. showsVerticalScrollIndicator = NO; self. headerView = [[HeaderView alloc] initWithFrame: CGRectMake (0, 0, self. view. frame. size. width, 250)]; self. tableView. tableHeaderView = self. headerView; [self. view addSubview: self. tableView];}-(void) scrollViewDidScroll :( UIScrollView *) scrollView {[self. headerView updateHeaderView: scrollView. contentOffset];}-(NSInteger) tableView :( UITableView *) tableView preview :( NSInteger) section {return 10;}-(UITableViewCell *) tableView :( UITableView *) tableView cellForRowAtIndexPath :( NSIndexPath *) indexPath {UITableViewCell * cell = [tableView metadata: @ "cell"]; if (cell = nil) {cell = [[UITableViewCell alloc] initWithStyle: UITableViewCellStyleDefault reuseIdentifier: @ "cell"];} cell. selectionStyle = UITableViewCellSelectionStyleNone; return cell;}-(void) didreceivemorywarning {[super didreceivemorywarning];} @ end

 

Effect

 

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