编辑代码

/方法1:创建时设置 frame
let rect = CGRect(x:10, y:10, width:300, height:30) 
let label=UILabel(frame:rect)
//添加到self.view上才会显示出来
self.view.addSubview(label)
//方法2:先创建,后设置 frame
let label = UILabel()
label.frame = CGRect(x:10, y:90, width:300, height:30) self.view.addSubview(label)
//设置背景色
label.backgroundColor =UIColor.green
//设置字体颜色
label.textColor = UIColor.red
//设置字体大小
label.font = UIFont.systemFont(ofsize: 14)
//设置文本对齐方式,默认左对齐
label.textAlignment = NSTextAlignment.right
//设置要显示的文本
label.text = "I am a label"
//当文字超出标签宽度时,自动调 文字大小,使其不被截断 label.adjustsFontSizeToFitWidth = true
//方法1:显示固定行数的文本
label.frame = CGRect(x:10, y:100,width:100, height:100) label.numberOfLines=2
label.text = "I am a label,I am a label,I am a label"
//方法 2:根据文字长度自己确定显示几行,只需设置numberOfLines=0 label.numberOfLines=0
label.text = "I am a label I am a label,I am a label"
//方法 1:创建一个系统内建样式的 UIButton
let button = UIButton(type: UIButtonType.system)
button.frame = CGRect(x:150,y:150, width:120, height:40)
button.setTitle("Click me", for: UIControlState.normal) button.titleLabel?.font = UIFont.systemFont(ofSize: 18)
button.addTarget(self, action: #selector(btnClick(_:)), for: UIControlEvents.touchUpInside)
button.layer.cornerRadius = 5.0 
//添加到 self.view 上才会显示出来
self.view.addSubview(button)
//方法 2:创建一个自定义的 UIButton,用于模拟复选框
let rect = CGRect(x:10, y:150, width:50, height:50)
let button = UIButton(frame:rect)
button.setImage(UIImage(named:"checknoneBtn.png"),for:UIControlState.normal)
button.setImage(UIImage(named:"checkedBtn.png"),for:UIControlState.selecd
button.addTarget(self, action: #selector(btnClick(_ :)),for: UIControlEvents. touchUpInside)
button.layer.cornerRadius =5.0 self.view.addSubview(button)
//Button 触摸后,需要调用的事件方法
func btnClick( _ sender : UIButton){
print ("Wuwu~~, I am here now") 
sender.isSelected = !sender.isSelected
}
// 创建一个 ,图片文件为"checkedBtn.png"
let imageViewRect = CGRect(x:0,y:350,width:100,height:100)
let imageView = UIImageView(frame: imageViewRect)
let img = UIImage(named: "checkedBtn.png")
imageView.image= img
//添加到 self.view 上才