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
步骤1:创建一个新项目
步骤2:在ViewController.swift中
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// CODE
let btn = UIButton(type: UIButtonType.System) as UIButton
btn.backgroundColor = UIColor.blueColor()
btn.setTitle("CALL TPT AGENT", forState: UIControlState.Normal)
btn.frame = CGRectMake(100, 100, 200, 100)
btn.addTarget(self, action: "clickMe:", forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(btn)
}
func clickMe(sender:UIButton!) {
print("CALL")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
其他回答
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")
}
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))
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。
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。
斯威夫特3
let btn = UIButton(type: .custom) as UIButton
btn.backgroundColor = .blue
btn.setTitle("Button", for: .normal)
btn.frame = CGRect(x: 100, y: 100, width: 200, height: 100)
btn.addTarget(self, action: #selector(clickMe), for: .touchUpInside)
self.view.addSubview(btn)
func clickMe(sender:UIButton!) {
print("Button Clicked")
}
输出
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