如何停止多个go例程

package main

import (
    "fmt"
    "sync"
    "time"
)

func worker(id int, wg *sync.WaitGroup, stopChan chan struct{}) {
    defer wg.Done()
    for {
        select {
        case <-stopChan:
            fmt.Printf("Worker %d stopped\n", id)
            return
        default:
            fmt.Printf("Worker %d is running\n", id)
            time.Sleep(time.Second) // 模拟工作
        }
    }
}

func main() {
    stopChan := make(chan struct{})
    wg := sync.WaitGroup{}

    // 启动多个goroutine
    for i := 1; i <= 5; i++ {
        wg.Add(1)
        go worker(i, &wg, stopChan)
    }

    // 停止所有goroutine
    time.Sleep(5 * time.Second)
    close(stopChan)
    wg.Wait()
    fmt.Println("All workers stopped")
}