【Golang】求解这道题

Question

 （代码是我写的），问题出在不知道何时关闭resChan，求大佬们看看思路对吗，正确的应该怎么写

package main
import (
	"fmt"
)
//练习
//放入 1 - 2000
func writeNum(numChan chan int) {
	
	for i := 1; i <= 2000; i++ {
		numChan<- i
	}
	//关闭
	close(numChan)
}

//取数, 求和, 存入 resChan
func sumNum(numChan chan int, resChan chan string, exitChan chan bool) {

	for {
		v, ok := <-numChan
		if !ok {
			break
		}
		var res int = 0
		for i := 1; i <= v; i++ {
			res += i
		}
		M := fmt.Sprintf("[%v] = %v", v, res)
		resChan<- M
	}
	exitChan<- true

}

func main() {

	//创建 3 个管道
	numChan := make(chan int, 2000)
	resChan := make(chan string, 2000)
	exitChan := make(chan bool, 10)

	go writeNum(numChan)
	go sumNum(numChan, resChan, exitChan)
	go sumNum(numChan, resChan, exitChan)
	go sumNum(numChan, resChan, exitChan)
	go sumNum(numChan, resChan, exitChan)
	go sumNum(numChan, resChan, exitChan)
	go sumNum(numChan, resChan, exitChan)
	go sumNum(numChan, resChan, exitChan)
	go sumNum(numChan, resChan, exitChan)
    
    //取出存入的8个true后，再关闭resChan
	for i:= 1; i <= 8; i++{
		<-exitChan
	}
	close(resChan)

	for m := range <-resChan {
		fmt.Println(m)
	}
	

}

Answer 1

用完的时候就关闭，只有在程序结束前关闭了，就可以了。