我正在try 设置栏按钮项的图像，因为我有如下图像:
分辨率为30*30，但当我将此图像指定给条形图按钮时，它看起来如下所示:
我以这种方式分配了映像:
如果我试着这样做，比如为按钮制作一个IBOutlet，然后通过编程设置图像，形成this个问题和代码:
// Outlet for bar button
@IBOutlet weak var fbButton: UIBarButtonItem!
// Set Image for bar button
var backImg: UIImage = UIImage(named: "fb.png")!
fbButton.setBackgroundImage(backImg, forState: .Normal, barMetrics: .Default)
但这件事什么都没发生，
有人能告诉我我做错了什么吗？
或者哪种击球手的方式可以做到这一点？
我已经通过以下代码编程实现了这一点:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//create a new button
let button: UIButton = UIButton.buttonWithType(UIButtonType.Custom) as! UIButton
//set image for button
button.setImage(UIImage(named: "fb.png"), forState: UIControlState.Normal)
//add function for button
button.addTarget(self, action: "fbButtonPressed", forControlEvents: UIControlEvents.TouchUpInside)
//set frame
button.frame = CGRectMake(0, 0, 53, 31)
let barButton = UIBarButtonItem(customView: button)
//assign button to navigationbar
self.navigationItem.rightBarButtonItem = barButton
}
//This method will call when you press button.
func fbButtonPressed() {
println("Share to fb")
}
}
结果将是:
同样，您也可以通过以下方式设置左侧的按钮:
self.navigationItem.leftBarButtonItem = barButton
结果将是:
个
如果您希望在使用默认的后退按钮返回时与导航控制器拥有相同的事务，则可以使用自定义的后退按钮使用以下代码来实现:
func backButtonPressed(sender:UIButton) {
navigationController?.popViewControllerAnimated(true)
}
对于SWIFT 3.0:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//create a new button
let button = UIButton.init(type: .custom)
//set image for button
button.setImage(UIImage(named: "fb.png"), for: UIControlState.normal)
//add function for button
button.addTarget(self, action: #selector(ViewController.fbButtonPressed), for: UIControlEvents.touchUpInside)
//set frame
button.frame = CGRect(x: 0, y: 0, width: 53, height: 51)
let barButton = UIBarButtonItem(customView: button)
//assign button to navigationbar
self.navigationItem.rightBarButtonItem = barButton
}
//This method will call when you press button.
func fbButtonPressed() {
print("Share to fb")
}
}
对于swift 4.0:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//create a new button
let button = UIButton(type: .custom)
//set image for button
button.setImage(UIImage(named: "fb.png"), for: .normal)
//add function for button
button.addTarget(self, action: #selector(fbButtonPressed), for: .touchUpInside)
//set frame
button.frame = CGRect(x: 0, y: 0, width: 53, height: 51)
let barButton = UIBarButtonItem(customView: button)
//assign button to navigationbar
self.navigationItem.rightBarButtonItem = barButton
}
//This method will call when you press button.
@objc func fbButtonPressed() {
print("Share to fb")
}
}