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iOS开发中视图的下拉放大和上拉模糊的效果实现

2019-10-21 18:57:22
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这篇文章主要介绍了iOS开发中视图的下拉放大和上拉模糊的效果实现,本文以秘密App的效果作为示例进行讲解,需要的朋友可以参考下
 

把"秘密"的Cell效果整体视图都放到scrollView中,基本是和secret app 一模一样的效果了.
代码如下:(模糊效果的类就不写了,大家可以搜"UIImage+ImageEffects",还要导入Accelerate.framework)
1.MTSecretAppEffect.h

 

复制代码代码如下:

 

#import <Foundation/Foundation.h>  
  
@interface MTSecretAppEffect : NSObject  
  
/** 
 *  创建整体的scrollView,把headScrollView和tableView全部加载在上面,靠它来上下滑动,其余的滑动全部禁止 
 * 
 *  @return mainScrollView 
 */  
- (UIScrollView *)createMainScrollView;  
  
/** 
 *  创建headScrollView 
 * 
 *  @return headScrollView 
 */  
- (UIScrollView *)createHeadScrollView;  
  
/** 
 *  创建头部的模糊view 
 * 
 *  @param scrollview headScrollView 
 * 
 *  @return blurImageView 
 */  
- (UIImageView *)createBlurImageViewOfView:(UIScrollView *)scrollview;  
  
/** 
 *  在- (void)scrollViewDidScroll:(UIScrollView *)scrollView 中调用的方法 
 * 
 *  @param scrollView 
 *  @param mainScrollView 
 *  @param tableView 
 *  @param headScrollView 
 *  @param blurImageView 
 */  
- (void)scrollDidScrollView:(UIScrollView *)scrollView withMainScrollView:(UIScrollView *)mainScrollView withTableView:(UITableView *)tableView withHeadScrollView:(UIScrollView *)headScrollView withBlurImageView:(UIImageView *)blurImageView;  
@end 

 


2.MTSecretAppEffect.m
复制代码代码如下:

#import "MTSecretAppEffect.h"  
#import "UIImage+ImageEffects.h"  
#import <QuartzCore/QuartzCore.h>  
  
#define HEADER_HEIGHT 200.0f  
#define HEADER_INIT_FRAME CGRectMake(0, 0, 320, HEADER_HEIGHT)  
  
const CGFloat kBarHeight = 50.0f;  
const CGFloat kBackgroundParallexFactor = 0.5f;  
const CGFloat kBlurFadeInFactor = 0.015f;  
  
  
@implementation MTSecretAppEffect  
  
// 欠缺:调用者设置代理  
- (UIScrollView *)createMainScrollView{  
  
    // 和Self.view同大小的底部ScrollView  
    UIScrollView *mainScrollView = [[UIScrollView alloc] initWithFrame:[UIApplication sharedApplication].keyWindow.frame];  
    mainScrollView.bounces = YES;  
    mainScrollView.alwaysBounceVertical = YES;  
    mainScrollView.contentSize = CGSizeZero;  
    mainScrollView.showsVerticalScrollIndicator = YES;  
    mainScrollView.scrollIndicatorInsets = UIEdgeInsetsMake(50.0f, 0, 0, 0);  
  
    return mainScrollView;  
      
}  
  
- (UIScrollView *)createHeadScrollView{  
  
    UIScrollView *headScrollView = [[UIScrollView alloc] initWithFrame:HEADER_INIT_FRAME];  
    headScrollView.scrollEnabled = NO;  
    headScrollView.contentSize = CGSizeMake(320, 1000);  
      
    return headScrollView;  
}  
  
- (UIImageView *)createBlurImageViewOfView:(UIScrollView *)scrollview{  
  
    UIGraphicsBeginImageContextWithOptions(scrollview.bounds.size, scrollview.opaque, 0.0);  
    [scrollview.layer renderInContext:UIGraphicsGetCurrentContext()];  
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();  
    UIGraphicsEndImageContext();  
    UIImageView *blurImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, HEADER_HEIGHT)];  
    blurImageView.image = [img applyBlurWithRadius:12 tintColor:[UIColor colorWithWhite:0.8 alpha:0.4] saturationDeltaFactor:1.8 maskImage:nil];  
    blurImageView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight; 
    blurImageView.alpha = 0;  
    blurImageView.backgroundColor = [UIColor clearColor];  
      
    return blurImageView;  
}  
  
- (void)scrollDidScrollView:(UIScrollView *)scrollView withMainScrollView:(UIScrollView *)mainScrollView withTableView:(UITableView *)tableView withHeadScrollView:(UIScrollView *)headScrollView withBlurImageView:(UIImageView *)blurImageView{  
      
    CGFloat y = 0.0f;  
    CGRect rect = HEADER_INIT_FRAME;   
    if (scrollView.contentOffset.y < 0.0f) {  
        // 下拉变大效果  
        y = fabs(MIN(0.0f, mainScrollView.contentOffset.y));  
        headScrollView.frame = CGRectMake(CGRectGetMinX(rect) - y / 2.0f, CGRectGetMinY(rect) - y, CGRectGetWidth(rect) + y, CGRectGetHeight(rect) + y);  
          
    }  
    else {  
          
        y = mainScrollView.contentOffset.y;  
        blurImageView.alpha = MIN(1 , y * kBlurFadeInFactor);  
        CGFloat backgroundScrollViewLimit = headScrollView.frame.size.height - kBarHeight;  
          
        if (y > backgroundScrollViewLimit) {  
            headScrollView.frame = (CGRect) {.origin = {0, y - headScrollView.frame.size.height + kBarHeight}, .size = {320, HEADER_HEIGHT}};  
            tableView.frame = (CGRect){.origin = {0, CGRectGetMinY(headScrollView.frame) + CGRectGetHeight(headScrollView.frame)}, .size = tableView.frame.size };  
            tableView.contentOffset = CGPointMake (0, y - backgroundScrollViewLimit);  
            CGFloat contentOffsetY = -backgroundScrollViewLimit * kBackgroundParallexFactor;  
            [headScrollView setContentOffset:(CGPoint){0,contentOffsetY} animated:NO];  
        }  
        else {  
            headScrollView.frame = rect;  
            tableView.frame = (CGRect){.origin = {0, CGRectGetMinY(rect) + CGRectGetHeight(rect)}, .size = tableView.frame.size };  
            [tableView setContentOffset:(CGPoint){0,0} animated:NO];  
            [headScrollView setContentOffset:CGPointMake(0, -y * kBackgroundParallexFactor)animated:NO];  
        }  
    }  
  
}  
  
@end 

 

 


3.main.m
复制代码代码如下:

#import "RootViewController.h"  
#import "CommentCell.h"  
#import "MTSecretAppEffect.h"  
  
#define HEADER_HEIGHT 200.0f  
  
@interface RootViewController () <UIScrollViewDelegate, UITableViewDataSource, UITableViewDelegate> 
  
@property (nonatomic,strong) MTSecretAppEffect *secretEffect;     // secretApp 效果对象  
@property (nonatomic,strong) UIScrollView *mainScrollView;        // 与view相同大小的scrollView  
@property (nonatomic,strong) UIScrollView *headScrollView;        //  
@property (nonatomic,strong) UIImageView  *blurImageView;         //  
@property (nonatomic,strong) UITableView *tableView;              //  
  
@end  
  
@implementation RootViewController  
  
- (void)viewDidLoad  
{  
    [super viewDidLoad];  
      
      
    // 0.创建SecretApp effect 效果对象  
    self.secretEffect = [[MTSecretAppEffect alloc] init];  
    // 1.主底部scrollView  
    self.mainScrollView = [self.secretEffect createMainScrollView];  
    self.mainScrollView.delegate = self;  
    self.view = self.mainScrollView;  
    // 2.head背景View  
    self.headScrollView = [self.secretEffect createHeadScrollView];  
    // 3.背景图片视图  
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, HEADER_HEIGHT)];  
    imageView.image = [UIImage imageNamed:@"secret.png"];  
    imageView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;  
    [self.headScrollView  addSubview:imageView];  
    // 4.模糊视图  
    _blurImageView = [self.secretEffect createBlurImageViewOfView:self.headScrollView];  
    [self.headScrollView addSubview:_blurImageView];  
    // 5.tableView  
    self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, HEADER_HEIGHT, CGRectGetWidth(self.view.frame), CGRectGetHeight(self.view.frame) - 50 ) style:UITableViewStylePlain];  
    self.tableView.scrollEnabled = NO;  
    self.tableView.delegate = self;  
    self.tableView.dataSource = self;  
    self.tableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];  
    self.tableView.separatorColor = [UIColor clearColor];  
    // 6.添加视图  
    [self.view addSubview:self.headScrollView];  
    [self.view addSubview:self.tableView];  
    // 7.设置一下  
    self.mainScrollView.contentSize = CGSizeMake(320, self.tableView.contentSize.height + CGRectGetHeight(self.headScrollView.frame));  
  
}  
  
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {  
      
    // 8.调用方法  
    [self.secretEffect scrollDidScrollView:scrollView withMainScrollView:self.mainScrollView withTableView:self.tableView withHeadScrollView:self.headScrollView withBlurImageView:self.blurImageView];  
}  
  
  
#pragma mark - 隐藏状态栏  
- (BOOL)prefersStatusBarHidden {  
    return YES;  
}  
  
  
#pragma mark - UITableView dataSource  
  
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {  
    return 1;  
}  
  
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {  
    return 20;  
}  
  
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {  
      
    return 40;  
}  
  
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {  
      
    CommentCell *cell = [tableView dequeueReusableCellWithIdentifier:[NSString stringWithFormat:@"Cell %ld", indexPath.row]];  
    if (!cell) {  
        cell = [[CommentCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:[NSString stringWithFormat:@"Cell %ld", indexPath.row]];  
    }  
    cell.textLabel.text = [NSString stringWithFormat:@"section = %ld row = %ld",indexPath.section,indexPath.row];  
  
    return cell;  
}  
  
- (void)didReceiveMemoryWarning  
{  
    [super didReceiveMemoryWarning];  
    // Dispose of any resources that can be recreated.  
}  
  
@end  
                 
效果图:
PPPPPPPPPPPPPPPPPPPPPP1
它主要效果:下拉头部视图放大,上拉视图模糊而且到一定位置固定不动,其他Cell可以继续上移.
封装的主要效果类:MTHeadEffect.m(.h文件省略,很简单的)

 

 

复制代码代码如下:

#import "MTHeadEffect.h"  
#import <QuartzCore/QuartzCore.h>  
#import <Accelerate/Accelerate.h>  
  
// 屏幕的物理宽度  
#define ScreenWidth  [UIScreen mainScreen].bounds.size.width  
#define HeadViewH  40  
  
CGFloat const kImageOriginHight = 200.f;  
  
@implementation MTHeadEffect  
  
+ (void)viewDidScroll:(UIScrollView *)tableView withHeadView:(UIImageView *)headView withBlur:(CGFloat)blur{  
  
    NSLog(@"y = %f",tableView.contentOffset.y);  
    if (tableView.contentOffset.y > kImageOriginHight - HeadViewH) {  
          
        headView.frame = CGRectMake(0, -(kImageOriginHight - HeadViewH), ScreenWidth, kImageOriginHight);  
        [[UIApplication sharedApplication].keyWindow addSubview:headView];  
          
    }else if ((tableView.contentOffset.y < kImageOriginHight - HeadViewH) && tableView.contentOffset.y > 0){  
          
        blur = (tableView.contentOffset.y) / 500.0 + 0.45;  
        headView.image = [[UIImage imageNamed:@"2"] boxblurImageWithBlur:blur];  
        headView.frame = CGRectMake(0, 0, ScreenWidth, kImageOriginHight);  
        [tableView addSubview:headView];  
          
    }else if (tableView.contentOffset.y <= 0){  
          
        // 放大效果---x,y坐标的增量和宽度,高度的增量保持一致  
        CGFloat offset  = -tableView.contentOffset.y;  
        headView.frame = CGRectMake(-offset,-offset, ScreenWidth+ offset * 2, kImageOriginHight + offset);  
        headView.image = [[UIImage imageNamed:@"2"] boxblurImageWithBlur:0.01];  
    }  
      
}  
  
@end  
  
@implementation UIImage (BlurEffect)  
  
// 为高斯模糊效果封装的一个类目  
-(UIImage *)boxblurImageWithBlur:(CGFloat)blur {  
      
    NSData *imageData = UIImageJPEGRepresentation(self, 1); // convert to jpeg  
    UIImage* destImage = [UIImage imageWithData:imageData];  
      
      
    if (blur < 0.f || blur > 1.f) {  
        blur = 0.5f;  
    }  
    int boxSize = (int)(blur * 40);  
    boxSize = boxSize - (boxSize % 2) + 1;  
      
    CGImageRef img = destImage.CGImage;  
      
    vImage_Buffer inBuffer, outBuffer;  
      
    vImage_Error error;  
      
    voidvoid *pixelBuffer;  
      
      
    //create vImage_Buffer with data from CGImageRef  
      
    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);  
      
    //create vImage_Buffer for output  
      
    pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));  
      
    if(pixelBuffer == NULL)  
        NSLog(@"No pixelbuffer");  
      
    outBuffer.data = pixelBuffer;  
    outBuffer.width = CGImageGetWidth(img);  
    outBuffer.height = CGImageGetHeight(img);  
    outBuffer.rowBytes = CGImageGetBytesPerRow(img);  
      
    // Create a third buffer for intermediate processing  
    voidvoid *pixelBuffer2 = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));  
    vImage_Buffer outBuffer2;  
    outBuffer2.data = pixelBuffer2;  
    outBuffer2.width = CGImageGetWidth(img);  
    outBuffer2.height = CGImageGetHeight(img);  
    outBuffer2.rowBytes = CGImageGetBytesPerRow(img);  
      
    //perform convolution  
    error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer2, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);  
    if (error) {  
        NSLog(@"error from convolution %ld", error);  
    }  
    error = vImageBoxConvolve_ARGB8888(&outBuffer2, &inBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);  
    if (error) {  
        NSLog(@"error from convolution %ld", error);  
    }  
    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,  
                                             (CGBitmapInfo)kCGImageAlphaNoneSkipLast);  
    CGImageRef imageRef = CGBitmapContextCreateImage (ctx);  
    UIImage *returnImage = [UIImage imageWithCGImage:imageRef];  
      
    //clean up  
    CGContextRelease(ctx);  
    CGColorSpaceRelease(colorSpace);  
      
    free(pixelBuffer);  
    free(pixelBuffer2);  
    CFRelease(inBitmapData);  
      
    CGImageRelease(imageRef);  
      
    return returnImage;  
}  
  
  
@end 

 

 

 

@main.m

复制代码代码如下:

- (void)viewDidLoad  
{  
    [super viewDidLoad];  
    // Do any additional setup after loading the view.  
    // tableView  
    self.testTableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, 320, 568) style:UITableViewStylePlain];  
    self.testTableView.delegate = self;  
    self.testTableView.dataSource = self;  
    [self.view addSubview:_testTableView];  
      
    /** 
     *  隐藏状态栏效果 
     *  1.系统提供了2种动画,一种是偏移,一种是渐隐 
     *  2.在plist文件中将”View controller-based status bar appearance” 设置为 “No” 
     */  
    [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationNone];  
      
    // headView不作为tableHeadView,而是覆盖在第一个Cell上  
    self.headView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 200)];  
    self.headView.image = [[UIImage imageNamed:@"2"] boxblurImageWithBlur:0.01];  
    self.headView.contentMode = UIViewContentModeScaleAspectFill;  //  图片展示全高度  
    self.headView.clipsToBounds = YES;  
    [self.testTableView addSubview:self.headView];  
      
}  
  
#pragma mark - scroll delegate 头部视图效果方法  
-(void)scrollViewDidScroll:(UIScrollView *)scrollView  
{  
      
    [MTHeadEffect viewDidScroll:scrollView withHeadView:self.headView withBlur:0.01];  
}  
  
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{  
  
    return 1;  
}  
  
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{  
  
    return 25;  
}  
  
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{  
  
    if (indexPath.row == 0) {  
        return 200;  
    }  
    return 40;  
  
}  
  
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{  
      
    static NSString *cellIdentf = @"cell";  
    UITableViewCell *cell = [tableView dequeueReusableHeaderFooterViewWithIdentifier:cellIdentf];  
    if (!cell) {  
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentf];  
    }  
    cell.textLabel.text = [NSString stringWithFormat:@"section = %ld row = %ld",indexPath.section,indexPath.row];  
    return cell;  
  

 

 

 

效果图:额,不会制作gif动图,所以不太好演示,反正关键代码已经给出,大家可以自己去尝试.
第三方FXBlurView做法的关键代码:

 

复制代码代码如下:

 

- (void)createBlurView{  
  
    self.blurView = [[FXBlurView alloc] initWithFrame:CGRectMake(0, 0, ScreenWidth, kOriginHight)];  
    self.blurView.tintColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:1];  
    self.blurView.blurRadius = 1.0;  
    self.blurView.dynamic = YES;  
    self.blurView.alpha = 0.0;  
    self.blurView.contentMode = UIViewContentModeBottom;  
  
}  
  
#pragma mark - scroll delegate 头部视图效果方法  
-(void)scrollViewDidScroll:(UIScrollView *)scrollView  
{  
      
    if (scrollView.contentOffset.y > 0) {  
         
        self.blurView.alpha = 1.0;  
        self.blurView.blurRadius = scrollView.contentOffset.y / 4.0;  
    }  
    if (scrollView.contentOffset.y == 0) {  
        self.blurView.alpha = 0.0;  
    }  
    if (scrollView.contentOffset.y < 0) {  
          
        CGFloat offset = - scrollView.contentOffset.y;  
        self.blurView.alpha = 0.0;  
        NSArray *indexPathArray = [self.testTableView indexPathsForVisibleRows];  
        HMTBlurTableViewCell *blurCell = (HMTBlurTableViewCell *)[self.testTableView cellForRowAtIndexPath:[indexPathArray objectAtIndex:0]];  
        blurCell.blurImageView.frame = CGRectMake(-offset, -offset, ScreenWidth + offset * 2, kOriginHight + offset);  
  
    }  

 


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