UIStackView 对UIView视图管理

UIStackView 对UIView子视图进行管理 ，对原片进行缩放

首先，建立一些视图，将视图放在数组中：

 NSMutableArray *array = [[NSMutableArray alloc] init];    for (int i = 0; i < 4; i ++) {        UIView *view = [[UIView alloc] init];        view.backgroundColor = [UIColor colorWithRed:arc4random()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1];        [array addObject:view];    } // 初始化方法，通过数组传入被管理的视图    self.stackView = [[UIStackView alloc] initWithArrangedSubviews:array];    [self.view addSubview:self.stackView];        self.stackView.frame = CGRectMake(0, 0, self.view.bounds.size.width, 500);    self.stackView.axis = UILayoutConstraintAxisVertical;   // 垂直方向    /*     typedef NS_ENUM(NSInteger, UILayoutConstraintAxis) {     UILayoutConstraintAxisHorizontal = 0,  水平布局     UILayoutConstraintAxisVertical = 1     竖直布局     };     */    self.stackView.distribution = UIStackViewDistributionFillEqually;   // 排列方式    /*     typedef NS_ENUM(NSInteger, UIStackViewDistribution) {     UIStackViewDistributionFill = 0,   // 充满，当只有一个控件时可以使用     UIStackViewDistributionFillEqually,    // 平分充满，每个控件占据相同尺寸排列充满     UIStackViewDistributionFillProportionally, // 会优先按照约束的尺寸进行排列，如果没有充满，会拉伸最后一个排列的控件充满     UIStackViewDistributionEqualSpacing,   // 等间距排列     UIStackViewDistributionEqualCentering, // 中心距离相等     } NS_ENUM_AVAILABLE_IOS(9_0);          */    self.stackView.alignment = UIStackViewAlignmentFill;    // 对齐模式    /*     typedef NS_ENUM(NSInteger, UIStackViewAlignment) {     UIStackViewAlignmentFill,  // 水平布局时为高度充满，竖直布局时为宽度充满     UIStackViewAlignmentLeading,   // 前边对齐     UIStackViewAlignmentTop = UIStackViewAlignmentLeading, // 顶部对齐     UIStackViewAlignmentFirstBaseline, // 第一个控件文字的基线对齐 水平布局有效     UIStackViewAlignmentCenter,    // 中心对齐     UIStackViewAlignmentTrailing,  // 后边对齐     UIStackViewAlignmentBottom = UIStackViewAlignmentTrailing, // 底部对齐     UIStackViewAlignmentLastBaseline,  // 基线对齐，水平布局有效     } NS_ENUM_AVAILABLE_IOS(9_0);          */        self.stackView.spacing = 5;    // 设置最小间距    self.stackView.baselineRelativeArrangement = YES;   // 设置布局是是否参照基线    self.stackView.layoutMarginsRelativeArrangement = NO;  // 设置布局时是否以控件的LayoutMargins为标准，默认为NO，是以控件的bounds为标准                UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(50, self.view.bounds.size.height - 50, 50, 50)];    [button2 addTarget:self action:@selector(removeView) forControlEvents:(UIControlEventTouchUpInside)];    [button2 setTitle:@"删除" forState:(UIControlStateNormal)];    button2.titleLabel.font = [UIFont systemFontOfSize:25];    [button2 setTitleColor:[UIColor blueColor] forState:(UIControlStateNormal)];     [self.view addSubview:button2];        UIButton *button1 = [[UIButton alloc] initWithFrame:CGRectMake(150, self.view.bounds.size.height - 50, 50, 50)];    [button1 addTarget:self action:@selector(addView) forControlEvents:(UIControlEventTouchUpInside)];    [button1 setTitle:@"添加" forState:(UIControlStateNormal)];    button1.titleLabel.font = [UIFont systemFontOfSize:25];    [button1 setTitleColor:[UIColor blueColor] forState:(UIControlStateNormal)];    [self.view addSubview:button1];            UIButton *button3 = [[UIButton alloc] initWithFrame:CGRectMake(250, self.view.bounds.size.height - 50, 50, 50)];    [button3 addTarget:self action:@selector(insertView) forControlEvents:(UIControlEventTouchUpInside)];    [button3 setTitle:@"插入" forState:(UIControlStateNormal)];    button3.titleLabel.font = [UIFont systemFontOfSize:25];    [button3 setTitleColor:[UIColor blueColor] forState:(UIControlStateNormal)];    [self.view addSubview:button3];    //响应事件- (void)addView{            UIView *newView = [[UIView alloc] init];    newView.backgroundColor = [UIColor colorWithRed:arc4random()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1];        [self.stackView addArrangedSubview:newView];    // 在添加的时候会有动画效果    [UIView animateWithDuration:1 animations:^{        [self.stackView layoutIfNeeded];    }];}- (void)removeView{            UIView *view = [[self.stackView arrangedSubviews] lastObject];  // 获取被管理的所有视图中的最后一个    [self.stackView removeArrangedSubview:view];    // 移除一个view    [UIView animateWithDuration:1 animations:^{        [self.stackView layoutIfNeeded];    }];}- (void)insertView{        UIView *newView = [[UIView alloc] init];    newView.backgroundColor = [UIColor colorWithRed:arc4random()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1];    NSArray *array = [self.stackView arrangedSubviews];    if (array.count > 2) {        [self.stackView insertArrangedSubview:newView atIndex:2];   // 插入一个视图        [UIView animateWithDuration:1 animations:^{            [self.stackView layoutIfNeeded];        }];    }}