美圖秀秀-美化圖片之【背景虛化】界面設計

　　本文是背景虛化界面設計，在美圖秀秀的背景虛化模塊主要是圖像的模糊處理，可以按照圓形和線性進行模糊處理，並生成選定的形狀。

　　在開發中遇到的誤區

1.模糊形狀使用UIImageView，遇到一些麻煩，即使你向UIImageView對象添加手勢，當你重載touchesBegan時，UIImageView對象也接收不到觸摸事件，而是直接傳遞給self.view。所以最後使用了UIButton來顯示模糊形狀圖片，這樣方便我們接收事件。

2.UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];初始化時用UIButtonTypeCustom才可以顯示原圖片，否則顯示圖片時時高亮狀態的圖片，很是奇怪。

如圖

先來幾張效果圖

一、從美化圖片首頁進入背景虛化

    else if ([text isEqualToString:@"背景虛化"])
    {
        FWBlurViewController *vc = [[FWBlurViewController alloc] initWithImage:self.image];
        [self presentViewController:vc animated:YES completion:^{
        }];
    }

二、初始化界面

self.selectedIndex = 0;
    
    self.view.backgroundColor = [UIColor blackColor];
    
    //顯示圖片
    self.imageView = [[UIImageView alloc] initWithImage:self.image];
    self.imageView.frame = CGRectMake(0, 0, WIDTH, HEIGHT - 115);
    self.imageView.contentMode = UIViewContentModeScaleAspectFit;
    [self.view addSubview:self.imageView];
    
    //保存與取消按鈕的添加
    UIImage *i1 = [UIImage imageNamed:@"[email protected]"];
    self.btnClose = [UIButton buttonWithType:UIButtonTypeCustom];
    [self.btnClose setImage:i1 forState:UIControlStateNormal];
    self.btnClose.frame = CGRectMake(20, HEIGHT - kCancelHeight - 10, kCancelHeight, kCancelHeight);
    [self.btnClose addTarget:self action:@selector(btnCancelOrSaveClicked:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.btnClose];
    
    UIImage *i2 = [UIImage imageNamed:@"[email protected]"];
    self.btnSave = [UIButton buttonWithType:UIButtonTypeCustom];
    [self.btnSave setImage:i2 forState:UIControlStateNormal];
    self.btnSave.frame = CGRectMake(WIDTH - kCancelHeight - 20, HEIGHT - kCancelHeight - 10, kCancelHeight, kCancelHeight);
    [self.view addSubview:self.btnSave];
    [self.btnSave addTarget:self action:@selector(btnCancelOrSaveClicked:) forControlEvents:UIControlEventTouchUpInside];
    
    [self setupSlider];
    
    self.styleBar = [[FWEffectBar alloc] initWithFrame:CGRectMake(90, HEIGHT - 55, 180, 55)];
    
    NSDictionary *autoDict = [[FWDataManager getDataSourceFromPlist] objectForKey:@"Blur"];
    NSArray *normalImageArr = [autoDict objectForKey:@"normalImages"];
    NSArray *hightlightedImageArr = [autoDict objectForKey:@"HighlightedImages"];
    NSArray *textArr = [autoDict objectForKey:@"Texts"];
    
    NSMutableArray *items = [[NSMutableArray alloc] initWithCapacity:0];
    
    for (int i = 0; i < [textArr count]; i++)
    {
        FWEffectBarItem *item = [[FWEffectBarItem alloc] initWithFrame:CGRectZero];
        [item setFinishedSelectedImage:[UIImage imageNamed:[hightlightedImageArr objectAtIndex:i]] withFinishedUnselectedImage:[UIImage imageNamed:[normalImageArr objectAtIndex:i]] ];
        item.title = [textArr objectAtIndex:i];
        [items addObject:item];
    }
    self.styleBar.items = items;
    self.styleBar.effectBarDelegate = self;
    [self.styleBar setSelectedItem:[self.styleBar.items objectAtIndex:0]];
    [self effectBar:self.styleBar didSelectItemAtIndex:0];
    [self.view addSubview:self.styleBar];
    
     self.btnBlurType = [UIButton buttonWithType:UIButtonTypeCustom];
    [self.btnBlurType setImage:[UIImage imageNamed:@"icon_blur_null"] forState:UIControlStateNormal];
    [self.btnBlurType addTarget:self action:@selector(btnBlurClicked:) forControlEvents:UIControlEventTouchUpInside];
    self.btnBlurType.frame = CGRectMake(20, HEIGHT - 90, 30, 30);
    [self.view addSubview:self.btnBlurType];

三、模糊形狀視圖管理

- (void)btnBlurClicked:(id)sender
{
    if (self.subView)
    {
        return;
    }
    
    [self setupSharpView];
}

- (void)hideShapeView
{
    [self.subView removeFromSuperview];
    self.subView = nil;
}
- (void)setupSharpView
{
    NSArray *arr = [NSArray arrayWithObjects:@"icon_blur_null", @"icon_blur_center", @"icon_blur_heart", @"icon_blur_star", @"icon_blur_heptagon", nil];
    self.subView = [[UIView alloc] initWithFrame:CGRectMake(10, HEIGHT - 135, 250, 35)];

    for (int i = 0; i < [arr count]; i++) {
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        [btn setImage:[UIImage imageNamed:[arr objectAtIndex:i]] forState:UIControlStateNormal];
        btn.frame = CGRectMake(10 + (35 + 10) * i, 0, 35, 35);
        [btn addTarget:self action:@selector(tap:) forControlEvents:UIControlEventTouchUpInside];
        [self.subView addSubview:btn];
    }
    
    [self.view addSubview:self.subView];
}

- (void)tap:(id)sender
{
    [self hideShapeView];
    
    [self.btnBlurType setImage:((UIButton *)sender).currentImage forState:UIControlStateNormal];
}


- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self hideShapeView];
}

小知識

1.[self.slider setThumbImage:[UIImage imageNamed:@"icon_slider_thumb"] forState:UIControlStateNormal];這段代碼可以修改UISLIDER的滑塊圖片，預設的滑塊太大~

2.UIImageView攔截事件要弱於UIButton

3.推薦創建UIButton時類型選擇UIButtonTypeCustom。

界面做完主攻具體功能實現了，估計還得1個星期左右~

下載項目

為自己加油！