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[操作系统]仿面包旅行个人中心下拉顶部背景放大高斯模糊效果


HeaderView.h

//// HeaderView.h// 仿面包旅行个人中心//// Created by wb145230@163.com on 15/5/14.// Copyright (c) 2015年 wb145230. All rights reserved.//#import <UIKit/UIKit.h>@interface HeaderView : UIView@property(nonatomic, strong) UIScrollView *imageScrollView;@property(nonatomic, strong) UIImageView *imageView;        //背景图片@property(nonatomic, strong) UIImageView *imageBackgroundView;   //要改变的背景图片/** * 改变顶部view的大小和高斯效果 * * @param offset scrollview滑动的记录 */-(void)updateHeaderView:(CGPoint) offset;@end

 

HeaderView.m

//// HeaderView.m// 仿面包旅行个人中心//// Created by wb145230@163.com on 15/5/14.// Copyright (c) 2015年 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"];    //高斯的背景图片    self.imageBackgroundView = [[UIImageView alloc] initWithFrame:self.imageScrollView.bounds];    [self setBlurryImage:image];    self.imageBackgroundView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;    self.imageBackgroundView.contentMode = UIViewContentModeScaleAspectFill;    [self.imageScrollView addSubview:self.imageBackgroundView];        //原图    self.imageView = [[UIImageView alloc] initWithFrame:self.imageScrollView.bounds];    self.imageView.image = image;    self.imageView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;    self.imageView.contentMode = UIViewContentModeScaleAspectFill;    [self.imageScrollView addSubview:self.imageView];  }    return self;}/** * 通过scrollview的滑动改变顶部view的大小和高斯效果 * * @param offset scrollview下滑的距离 */-(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));  }}/** * 高斯图片 * * @param originalImage 需要高斯的图片 */- (void)setBlurryImage:(UIImage *)originalImage {    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{    UIImage *blurredImage = [self blurryImage:originalImage withBlurLevel:0.9];        dispatch_async(dispatch_get_main_queue(), ^{      self.imageView.alpha = 0.0;      self.imageBackgroundView.image = blurredImage;    });  });  }/** * 高斯背景 * * @param image  需要高斯模糊的图片 * @param blur   高斯模糊的值 * * @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 = CGImageGetDataProvider(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 = CGBitmapContextCreateImage (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// 仿面包旅行个人中心//// Created by wb145230@163.com on 15/5/14.// Copyright (c) 2015年 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// 仿面包旅行个人中心//// Created by wb145230@163.com on 15/5/14.// Copyright (c) 2015年 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 numberOfRowsInSection:(NSInteger)section {  return 10;}- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];  if (cell == nil) {    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"];  }  cell.selectionStyle = UITableViewCellSelectionStyleNone;  return cell;}- (void)didReceiveMemoryWarning {  [super didReceiveMemoryWarning];}@end

 

效果

 

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