在导航栏中添加彩色图像作为右侧栏按钮项

Question

我添加了一个带有彩色背景图像的右侧导航栏项：

let rightButton = UIBarButtonItem(image: UIImage(named: "avatar")!,
                                  style: UIBarButtonItemStyle.Plain, 
                                  target: self,     
                                  action: #selector(self.rightNavBarItemAction))

navigationItem.rightBarButtonItem = rightButton

我没有将图像作为按钮的背景（颜色），而是获得了一个白色的占位符。

Answer 1

您可以将图像的渲染模式更新为UIImageRenderingMode.alwaysOriginal。

Swift 4.2：

let img = UIImage(named: "avatar")!.withRenderingMode(.alwaysOriginal)
let rightButton = UIBarButtonItem(image: img,
                                      style: UIBarButtonItem.Style.Plain,
                                      target: self,
                                      action: #selector(self.rightNavBarItemAction))

斯威夫特4：

let img = UIImage(named: "avatar")!.withRenderingMode(.alwaysOriginal)
let rightButton = UIBarButtonItem(image: img,
                                      style: UIBarButtonItemStyle.Plain,
                                      target: self,
                                      action: #selector(self.rightNavBarItemAction))

斯威夫特3：

let img = UIImage(named: "avatar")!.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
let rightButton = UIBarButtonItem(image: img,
                                      style: UIBarButtonItemStyle.Plain,
                                      target: self,
                                      action: #selector(self.rightNavBarItemAction))

或者，您可以像弗拉基米尔的答案一样设置自定义视图。

Answer 2

要实现这一点，你需要一个按钮UIButton，设置该按钮的图像，然后将其指定为自定义视图，如果你的UIBarButtonItem：

let button = UIButton()
button.frame = CGRectMake(0, 0, 51, 31)
button.setImage(UIImage(named: "avatar"), forState: .Normal)
button.addTarget(self, action: #selector(self.rightNavBarItemAction)), forControlEvents: .TouchUpInside)

let barButton = UIBarButtonItem()
barButton.customView = button
self.navigationItem.rightBarButtonItem = barButton