我如何以编程方式创建图形元素(如UIButton)在Swift?我试图创建和添加按钮到一个视图,但不能。
当前回答
这是可能的。除了使用swift语法之外,您几乎可以以相同的方式完成所有操作。例如,你可以用这样的代码创建一个UIButton:
var button: UIButton = UIButton(frame: CGRectMake(0, 0, 100, 100))
其他回答
Swift:以编程方式创建Ui按钮
let myButton = UIButton()
myButton.titleLabel!.frame = CGRectMake(15, 54, 300, 500)
myButton.titleLabel!.text = "Button Label"
myButton.titleLabel!.textColor = UIColor.redColor()
myButton.titleLabel!.textAlignment = .Center
self.view.addSubview(myButton)
Swift 3
let button = UIButton()
button.frame = CGRect(x: self.view.frame.size.width - 60, y: 60, width: 50, height: 50)
button.backgroundColor = UIColor.red
button.setTitle("your Button Name", for: .normal)
button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
self.view.addSubview(button)
func buttonAction(sender: UIButton!) {
print("Button tapped")
}
Swift 4+
let button = UIButton()
button.frame = CGRect(x: self.view.frame.size.width - 60, y: 60, width: 50, height: 50)
button.backgroundColor = UIColor.red
button.setTitle("Name your Button ", for: .normal)
button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
self.view.addSubview(button)
@objc func buttonAction(sender: UIButton!) {
print("Button tapped")
}
从storyboard创建UIButton: 1 -将UIButton对象从对象库拖到storyboard文件中的ViewController 2 -节目助理编辑 3 -从上面创建的UIButton中右键拖动到你的类中。结果如下:
@IBAction func buttonActionFromStoryboard(sender: UIButton)
{
println("Button Action From Storyboard")
}
为创建UIButton编程: 1-写入“override func viewDidLoad()”:
let uiButton = UIButton.buttonWithType(UIButtonType.System) as UIButton
uiButton.frame = CGRectMake(16, 116, 288, 30)
uiButton.setTitle("Second", forState: UIControlState.Normal);
uiButton.addTarget(self, action: "buttonActionFromCode:", forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(uiButton)
2-添加IBAction功能:
@IBAction func buttonActionFromCode(sender:UIButton)
{
println("Button Action From Code")
}
下面是一个完整的解决方案,以编程方式添加一个UIButton与targetAction。 斯威夫特2.2
override func viewDidLoad() {
super.viewDidLoad()
let button = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))
button.backgroundColor = .greenColor()
button.setTitle("Test Button", forState: .Normal)
button.addTarget(self, action: #selector(buttonAction), forControlEvents: .TouchUpInside)
self.view.addSubview(button)
}
func buttonAction(sender: UIButton!) {
print("Button tapped")
}
使用NSLayoutConstraint而不是frame来正确地为每个iPhone屏幕放置按钮可能更好。
Swift 3.1的更新代码:
override func viewDidLoad() {
super.viewDidLoad()
let button = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))
button.backgroundColor = .green
button.setTitle("Test Button", for: .normal)
button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
self.view.addSubview(button)
}
func buttonAction(sender: UIButton!) {
print("Button tapped")
}
Swift 4.2的更新代码:
override func viewDidLoad() {
super.viewDidLoad()
let button = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))
button.backgroundColor = .green
button.setTitle("Test Button", for: .normal)
button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
self.view.addSubview(button)
}
@objc func buttonAction(sender: UIButton!) {
print("Button tapped")
}
如果func buttonAction声明为private或internal,上述方法仍然有效。
API没有改变——只有语法改变了。你可以创建一个UIButton并像这样添加它:
var button = UIButton(frame: CGRectMake(0, 0, 50, 50))
self.view.addSubview(button) // assuming you're in a view controller
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