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
var sampleButton:UIButton?
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(animated: Bool) {
sampleButton = UIButton(type: .RoundedRect)
//sampleButton.frame = CGRect(x:50, y:500, width:70, height:50)
sampleButton!.setTitle("Sample \n UI Button", forState: .Normal)
sampleButton!.titleLabel?.lineBreakMode = .ByWordWrapping
sampleButton!.titleLabel?.textAlignment = .Center
sampleButton!.setTitleColor(UIColor.whiteColor(), forState: .Normal)
sampleButton!.layer.cornerRadius = 6
sampleButton!.backgroundColor = UIColor.redColor().colorWithAlphaComponent(0.6)
sampleButton?.tintColor = UIColor.brownColor()
//Add padding around text
sampleButton!.titleEdgeInsets = UIEdgeInsetsMake(-10,-10,-10,-10)
sampleButton!.contentEdgeInsets = UIEdgeInsetsMake(5,5,5,5)
//Action set up
sampleButton!.addTarget(self, action: "sampleButtonClicked", forControlEvents: .TouchUpInside)
self.view.addSubview(sampleButton!)
//Button Constraints:
sampleButton!.translatesAutoresizingMaskIntoConstraints = false
//To anchor above the tab bar on the bottom of the screen:
let bottomButtonConstraint = sampleButton!.bottomAnchor.constraintEqualToAnchor(bottomLayoutGuide.topAnchor, constant: -20)
//edge of the screen in InterfaceBuilder:
let margins = view.layoutMarginsGuide
let leadingButtonConstraint = sampleButton!.leadingAnchor.constraintEqualToAnchor(margins.leadingAnchor)
bottomButtonConstraint.active = true
leadingButtonConstraint.active = true
}
func sampleButtonClicked(){
print("sample Button Clicked")
}
其他回答
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))
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
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")
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var imageView = UIImageView(frame: CGRectMake(100, 150, 150, 150));
var image = UIImage(named: "BattleMapSplashScreen.png");
imageView.image = image;
self.view.addSubview(imageView);
}
// 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")
}
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