1.创建新项目

2.设计布局,main.storyboard中，在控件库中

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3.布局控件关联控制器

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4.设置事件或者显示模式

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5.编写代码：

import UIKit

class ViewController: UIViewController {
    @IBAction func btn1(_ sender: UIButton) {
        label1.text="我的*个程序"
    }
    @IBOutlet weak var label1: UILabel!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }
    @IBOutlet weak var hello: UILabel!
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

*后运行：

点击按钮改变label控件文字