如何将配置文件图像放置在目标 c 中圆角的 uibarbuttonitem 上？

Question

我想让我的 UIbarbuttonItem 带有圆角（右侧）。 I referred the link to implement 还是我没有得到。图片来自 URL。我的代码是，

 dispatch_async(dispatch_get_global_queue(0,0), ^{

 NSData * data = [[NSData alloc] initWithContentsOfURL: [NSURL   URLWithString:userImage]];
    if ( data == nil )
        return;
    dispatch_async(dispatch_get_main_queue(), ^{
        // WARNING: is the cell still using the same data by this point??
        UIImage *img = [UIImage imageWithData: data];

        UIImage *btnImage = [self imageWithImage:img scaledToSize:CGSizeMake(50, 50)];
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
        // btn.bounds = CGRectMake( 0, 0, btnImage.size.width, btnImage.size.height );
        [btn addTarget:self action:@selector(action:) forControlEvents:UIControlEventTouchDown];
        [btn setImage:btnImage forState:UIControlStateNormal];
        UIBarButtonItem *btnItem = [[UIBarButtonItem alloc] initWithCustomView:btn];
        self.navigationItem.rightBarButtonItem = btnItem;
    });

});

我需要实现与图像相同。我做错了什么，请任何人帮我解决这个问题。

Answer 1

这是 oxigen 的（优秀）答案转换为 Swift 3 / Swift 4：

override func viewDidLoad()
{
    super.viewDidLoad()

    let url = URL(string: "http://i.stack.imgur.com/EbYBY.jpg")!
    let data = try! Data(contentsOf: url)
    let img = UIImage(data: data)
    let imageView = UIImageView(frame: CGRect(x: 0.0, y: 0.0, width: 40.0, height: 40.0))
    imageView.image = img?.withRenderingMode(.alwaysOriginal)
    imageView.layer.cornerRadius = 20.0
    imageView.layer.masksToBounds = true
    let barButton = UIBarButtonItem(customView: imageView)
    navigationItem.setLeftBarButton(barButton, animated: false)
}

（给定的 URL 现在已经失效了，但是有了正确的 URL 或其他图像，代码应该可以工作。）

Answer 2

它对我有用：

- (void)viewDidLoad
 {
 [super viewDidLoad];
  NSString* url = @"http://i.stack.imgur.com/EbYBY.jpg";
 NSData * data = [[NSData alloc] initWithContentsOfURL: [NSURL   URLWithString:url]];
UIImage* img = [UIImage imageWithData:data];

UIImageView* v = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 40, 40)];
v.image = img;
v.layer.masksToBounds = YES;
v.layer.cornerRadius = 20;

UIBarButtonItem* rightBtn = [[UIBarButtonItem alloc] initWithCustomView:v];
self.navigationItem.rightBarButtonItem = rightBtn;
}

Answer 3

你可以用这个让按钮变圆

UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.frame = CGRectMake(0,0,100,100)//set your frame's size
[btn setImage:[UIImage imageNamed:btnImage]  forState:UIControlStateNormal];  
btn.layer.masksToBounds = NO;
btn.layer.cornerRadius = btn.bounds.size.width/2;;

UIBarButtonItem * btnItem = [[UIBarButtonItem alloc] initWithCustomView:btn];
[self.navigationItem setRightBarButtonItems:@[btnItem]];