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
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。
其他回答
你可以这样创建,也可以这样添加动作....
import UIKit
let myButton = UIButton(frame: CGRect(x: 0, y: 0, width: 50, height: 50))
init(nibName nibNameOrNil: String!, bundle nibBundleOrNil: NSBundle!)
{ super.init(nibName: nibName, bundle: nibBundle)
myButton.targetForAction("tappedButton:", withSender: self)
}
func tappedButton(sender: UIButton!)
{
println("tapped button")
}
我通常会设置uibutton的扩展。斯威夫特5。
let button: UIButton = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
button.setup(title: "OK", x: 100, y: 430, width: 220, height: 80, color: .yellow)
buttonD.setTitleColor(.black, for: .normal)
}
extension UIButton {
func setup(title: String, x: CGFloat, y: CGFloat, width: CGFloat, height: CGFloat, color: UIColor){
frame = CGRect(x: x, y: y, width: width, height: height)
backgroundColor = color
setTitle(title , for: .normal)
}
}
// UILabel:
let label = UILabel()
label.frame = CGRectMake(35, 100, 250, 30)
label.textColor = UIColor.blackColor()
label.textAlignment = NSTextAlignment.Center
label.text = "Hello World"
self.view.addSubview(label)
// UIButton:
let btn: UIButton = UIButton(type: UIButtonType.Custom) as UIButton
btn.frame = CGRectMake(130, 70, 60, 20)
btn.setTitle("Click", forState: UIControlState.Normal)
btn.setTitleColor(UIColor.blackColor(), forState: .Normal)
btn.addTarget(self, action:Selector("clickAction"), forControlEvents: UIControlEvents.TouchUpInside)
view.addSubview(btn)
// Button Action:
@IBAction func clickAction(sender:AnyObject)
{
print("Click Action")
}
你可以通过这种方式添加UIButton,UIlable和UITextfield。
UIButton代码
// var button = UIButton.buttonWithType(UIButtonType.System) as UIButton
let button = UIButton(type: .System) // let preferred over var here
button.frame = CGRectMake(100, 100, 100, 50)
button.backgroundColor = UIColor.greenColor()
button.setTitle("Button", forState: UIControlState.Normal)
button.addTarget(self, action: "Action:", forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(button)
UILabel代码
var label: UILabel = UILabel()
label.frame = CGRectMake(50, 50, 200, 21)
label.backgroundColor = UIColor.blackColor()
label.textColor = UIColor.whiteColor()
label.textAlignment = NSTextAlignment.Center
label.text = "test label"
self.view.addSubview(label)
UITextField 代码
var txtField: UITextField = UITextField()
txtField.frame = CGRectMake(50, 70, 200, 30)
txtField.backgroundColor = UIColor.grayColor()
self.view.addSubview(txtField)
希望这对你有帮助。
将此代码添加到viewDidLoad中 / /添加按钮
var button=UIButton(frame: CGRectMake(150, 240, 75, 30))
button.setTitle("Next", forState: UIControlState.Normal)
button.addTarget(self, action: "buttonTapAction:", forControlEvents: UIControlEvents.TouchUpInside)
button.backgroundColor = UIColor.greenColor()
self.view.addSubview(button)
将这个函数写在它的外面,当你点击按钮时,这个函数将被调用
func buttonTapAction(sender:UIButton!)
{
println("Button is working")
}
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