在左对齐的导航栏中添加徽标

Question

我对如何在左对齐的 NavigationBar 中获取图像感到困惑。我了解如何替换中心的标题。

基本上，我有一个嵌入在导航栏控制器中的视图控制器。在那个视图控制器中，我在中间有一个搜索表单，在右边有一个栏按钮，我试图在左侧放置一个图像徽标。

下面是我所了解的如何放置图片，但如何让它左对齐？

    let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 50, height: 50))
imageView.contentMode = .ScaleAspectFit
let image = UIImage(named: "imageName")
imageView.image = image
navigationItem.titleView = imageView

Answer 1

创建一个带图像的 BarButton 项目。

如下所示将其作为左栏按钮项分配给导航栏。

Objective C

UIBarButtonItem *logo = [[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:"imageName"] style:UIBarButtonItemStylePlain target:self action:@selector(methodName)];

self.navigationItem.leftBarButtonItem = logo;

SWIFT

let logo = UIBarButtonItem(image: UIImage (named: "imageName"), style: UIBarButtonItemStyle.plain, target: self, action: methodName)

self.navigationItem.leftBarButtonItem = logo

希望对您有所帮助..

Answer 2

您可以将项目数组分配给 navigationBar 的 leftBarButtonItems 属性。您应该添加一个数组，因为左侧和徽标之间通常没有 space，这看起来不太好。这是一个例子：

func setUpUI() {
    let logoImage = UIImage.init(named: "logoImage")
    let logoImageView = UIImageView.init(image: logoImage)
    logoImageView.frame = CGRectMake(-40, 0, 150, 25)
    logoImageView.contentMode = .ScaleAspectFit
    let imageItem = UIBarButtonItem.init(customView: logoImageView)
    let negativeSpacer = UIBarButtonItem.init(barButtonSystemItem: .FixedSpace, target: nil, action: nil)
    negativeSpacer.width = -25
    navigationItem.leftBarButtonItems = [negativeSpacer, imageItem]
}

它左边的负 spacer 会把它推过来一点，你可以从那里调整它。

Answer 3

对于iOS11我们需要给BarButtomItem的image view添加约束

 func addLeftBarIcon(named:String) {

    let logoImage = UIImage.init(named: named)
    let logoImageView = UIImageView.init(image: logoImage)
    logoImageView.frame = CGRect(x:0.0,y:0.0, width:60,height:25.0)
    logoImageView.contentMode = .scaleAspectFit
    let imageItem = UIBarButtonItem.init(customView: logoImageView)
    let widthConstraint = logoImageView.widthAnchor.constraint(equalToConstant: 60)
    let heightConstraint = logoImageView.heightAnchor.constraint(equalToConstant: 25)
     heightConstraint.isActive = true
     widthConstraint.isActive = true
     navigationItem.leftBarButtonItem =  imageItem
}

祝一切顺利

Answer 4

根据@Warrior 的回答，

对于 Objective-C、iOS11+ 和徽标的相关布局。


    // create Youtube icon imageView
    UIImageView *youtubeImageView = [[UIImageView alloc] init];
    youtubeImageView.translatesAutoresizingMaskIntoConstraints = false;
    youtubeImageView.contentMode = UIViewContentModeScaleAspectFit;
    youtubeImageView.image = [UIImage imageNamed:@"youtube_icon"];
    UIBarButtonItem *imageItem = [[UIBarButtonItem alloc] initWithCustomView:youtubeImageView];
    
    // set constraints
    float width = self.view.frame.size.width * 0.3;
    float height = width * 178 / 794; // width * 1/ratio

    [youtubeImageView.widthAnchor constraintEqualToConstant:width].active = true;
    [youtubeImageView.heightAnchor constraintEqualToConstant:height].active = true;
    self.navigationItem.leftBarButtonItem = imageItem;

在左对齐的导航栏中添加徽标

Adding a logo in Navigation Bar that is left aligned

uinavigationbar

ios

swift