IOS开发自定义view方法规范示例

下面我将为大家分享如何制作iOS开发自定义view的方法规范示例。

什么是自定义view

自定义view是指程序员自己定义的在iOS应用中用来显示内容的视图控件，可以自己控制视图的外观和行为，更灵活地满足业务需求。

自定义view可以具有以下特点：

• 可以自由定义视图外观
• 可以自定义视图的交互
• 可以封装业务逻辑

制作自定义view的步骤

1. 继承UIView类，实现 initWithCoder 方法。

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        [self setupSubviews];
    }
    return self;
}

1. 在setupSubviews方法中创建自定义的子控件，并添加到父视图中。

- (void)setupSubviews {
    self.imageView = [[UIImageView alloc] init];
    self.imageView.contentMode = UIViewContentModeScaleAspectFill;
    self.imageView.clipsToBounds = YES;
    [self addSubview:self.imageView];

    self.titleLabel = [[UILabel alloc] init];
    self.titleLabel.font = [UIFont systemFontOfSize:14];
    self.titleLabel.textColor = [UIColor blackColor];
    [self addSubview:self.titleLabel];

    self.detailLabel = [[UILabel alloc] init];
    self.detailLabel.font = [UIFont systemFontOfSize:12];
    self.detailLabel.textColor = [UIColor grayColor];
    [self addSubview:self.detailLabel];
}

1. 在layoutSubviews方法中设置子控件的位置和大小。

- (void)layoutSubviews {
    [super layoutSubviews];

    self.imageView.frame = CGRectMake(0, 0, self.frame.size.width, self.frame.size.width);
    self.titleLabel.frame = CGRectMake(0, CGRectGetMaxY(self.imageView.frame) + 10, self.frame.size.width, 20);
    self.detailLabel.frame = CGRectMake(0, CGRectGetMaxY(self.titleLabel.frame) + 5, self.frame.size.width, 15);
}

1. 添加可供外部调用的属性和方法，例如：

@property (nonatomic, strong) UIImage *image;
@property (nonatomic, copy) NSString *titleText;
@property (nonatomic, copy) NSString *detailText;

- (void)setImage:(UIImage *)image titleText:(NSString *)titleText detailText:(NSString *)detailText;

1. 实现对外部属性和方法的具体逻辑，例如：

- (void)setImage:(UIImage *)image titleText:(NSString *)titleText detailText:(NSString *)detailText {
    self.imageView.image = image;
    self.titleLabel.text = titleText;
    self.detailLabel.text = detailText;
}

1. 在需要使用自定义view的地方，导入头文件，并创建实例，例如：

MyCustomView *customView = [[MyCustomView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
customView.image = [UIImage imageNamed:@"avatar.png"];
customView.titleText = @"John Smith";
customView.detailText = @"Software Engineer";
[self.view addSubview:customView];

示例1：自定义九宫格视图

1. 创建类似于UICollectionView的布局方式。

- (void)layoutSubviews {
    [super layoutSubviews];

    CGFloat itemWidth = (self.frame.size.width - padding * (columnCount + 1)) / columnCount;
    CGFloat itemHeight = itemWidth;

    for (NSInteger i = 0; i < self.subviews.count; i++) {
        NSInteger row = i / columnCount;
        NSInteger column = i % columnCount;

        UIView *itemView = [self.subviews objectAtIndex:i];
        itemView.frame = CGRectMake(padding + (itemWidth + padding) * column, padding + (itemHeight + padding) * row, itemWidth, itemHeight);
    }
}

1. 添加对外暴露的方法，供外部设置内容。

- (void)setImages:(NSArray<UIImage *> *)images {
    _images = images;

    for (UIView *subview in self.subviews) {
        [subview removeFromSuperview];
    }

    for (NSInteger i = 0; i < images.count; i++) {
        UIImage *image = [images objectAtIndex:i];
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
        imageView.contentMode = UIViewContentModeScaleAspectFill;
        imageView.clipsToBounds = YES;
        [self addSubview:imageView];
    }
}

1. 使用自定义view的代码示例：

MyGridView *gridView = [[MyGridView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
gridView.columnCount = 3;
gridView.padding = 5;
gridView.images = @[[UIImage imageNamed:@"image1.jpg"], [UIImage imageNamed:@"image2.jpg"], [UIImage imageNamed:@"image3.jpg"], [UIImage imageNamed:@"image4.jpg"]];
[self.view addSubview:gridView];

示例2：自定义轮播图视图

1. 使用UIScrollView和UIPageControl实现轮播图的滚动和分页。

- (void)setupSubviews {
    self.scrollView = [[UIScrollView alloc] initWithFrame:self.bounds];
    self.scrollView.pagingEnabled = YES;
    self.scrollView.delegate = self;
    [self addSubview:self.scrollView];

    self.pageControl = [[UIPageControl alloc] init];
    self.pageControl.numberOfPages = self.imageUrls.count;
    self.pageControl.currentPage = 0;
    [self addSubview:self.pageControl];
}

1. 加载网络图片，并在滚动时更新UIPageControl。

- (void)loadImageWithUrl:(NSURL *)url intoImageView:(UIImageView *)imageView {
    NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        if (error == nil && data.length > 0) {
            UIImage *image = [UIImage imageWithData:data];
            dispatch_async(dispatch_get_main_queue(), ^{
                imageView.image = image;
            });
        }
    }];

    [task resume];
}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGFloat offset = scrollView.contentOffset.x;
    NSInteger pageIndex = (NSInteger)((offset + 0.5 * scrollView.frame.size.width) / scrollView.frame.size.width);
    self.pageControl.currentPage = pageIndex;
}

- (void)reloadScrollView {
    for (UIView *subview in self.scrollView.subviews) {
        [subview removeFromSuperview];
    }

    CGFloat width = self.bounds.size.width;
    CGFloat height = self.bounds.size.height;

    for (NSInteger i = 0; i < self.imageUrls.count; i++) {
        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(i * width, 0, width, height)];
        [self.scrollView addSubview:imageView];

        NSURL *url = [NSURL URLWithString:[self.imageUrls objectAtIndex:i]];
        [self loadImageWithUrl:url intoImageView:imageView];
    }

    self.scrollView.contentSize = CGSizeMake(width * self.imageUrls.count, height);
}

1. 使用自定义view的代码示例：

MyCarouselView *carouselView = [[MyCarouselView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 200)];
carouselView.imageUrls = @[@"http://www.example.com/image1.jpg", @"http://www.example.com/image2.jpg", @"http://www.example.com/image3.jpg"];
[self.view addSubview:carouselView];

以上是制作iOS开发自定义view方法规范示例的详细步骤和两个示例说明。希望对大家有所帮助。