在圆形 UIImageView 后面创建阴影的问题答案

【问题标题】：Problem creating shadow behind rounded UIImageView在圆形 UIImageView 后面创建阴影的问题
【发布时间】：2023-03-17 02:29:02
【问题描述】：

我有一个圆形的 UIImageView。当我给它添加阴影时，我失去了圆角。我怎样才能有一个圆角的阴影？

//Avatar
        CGRect rect;
        rect = CGRectMake(13, 10, 48, 48);
        avatarImageView = [[TCImageView alloc] initWithURL:[NSURL URLWithString:nil] placeholderImage:[UIImage imageNamed:@"placeholder.png"]];
        avatarImageView.frame = rect;
        avatarImageView.caching = YES;

        //Round the corners
        CALayer * layer = [avatarImageView layer];
        [layer setMasksToBounds:YES];
        [layer setCornerRadius:9.0];

        //Add a shadow
        avatarImageView.layer.shadowColor = [UIColor grayColor].CGColor;
        avatarImageView.layer.shadowOffset = CGSizeMake(0, 1);
        avatarImageView.layer.shadowOpacity = 1;
        avatarImageView.layer.shadowRadius = 9.0;
        avatarImageView.clipsToBounds = NO;

        [self.contentView addSubview: avatarImageView];

【问题讨论】：

标签： iphone objective-c uiimageview core-animation calayer

【解决方案1】：

使您的图像显示为圆角的功能是隐藏阴影的功能：[layer setMasksToBounds: YES]。您可以做的是将 ImageView 放在 UIView 子视图中，该子视图充当提供阴影的容器。

所以代码可能看起来像这样（我只是输入它，但没有编译它）

//Avatar
CGRect rect;
rect = CGRectMake(13, 10, 48, 48);
avatarImageView = [[TCImageView alloc] initWithURL:[NSURL URLWithString:nil]   placeholderImage:[UIImage imageNamed:@"placeholder.png"]];
avatarImageView.frame = rect;
avatarImageView.caching = YES; 

//Round the corners
CALayer * layer = [avatarImageView layer];
[layer setMasksToBounds:YES];
[layer setCornerRadius:9.0];

//Add a shadow by wrapping the avatar into a container
UIView * container = [[UIView alloc] initWithFrame: rect];
avatarImageView.frame = CGRectMake(0,0,rect.size.width, rect.size.height);

// setup shadow layer and corner
container.layer.shadowColor = [UIColor grayColor].CGColor;
container.layer.shadowOffset = CGSizeMake(0, 1);
container.layer.shadowOpacity = 1;
container.layer.shadowRadius = 9.0;
container.layer.cornerRadius = 9.0;
container.clipsToBounds = NO;

// combine the views
[container addSubview: avatarImageView];
[self.contentView addSubview: container];
[container release];

【讨论】：