goroutine 错误：返回的参数太多

Question

在使用goroutine之前，我有一个函数工作：

res, err := example(a , b)

if err != nil {

 return Response{

   ErrCode: 1,

   ErrMsg:"error",

 }

}

响应是结构定义的错误信息。当我使用goroutine时：

var wg sync.WaitGroup()

wg.Add(1)

go func(){

   defer wg.Done()

   res, err := example(a , b)

   if err != nil {

      return Response{

         ErrCode: 1,

         ErrMsg:"error",

    }

}()

wg.Wait()

然后我得到了

too many arguments to return

    have (Response)

    want ()

Answer 1

您需要使用通道来实现您想要的：func main() {&nbsp; &nbsp; c := make(chan Response)&nbsp; &nbsp; go func() {&nbsp; &nbsp; &nbsp; &nbsp; res, err := example(a , b)&nbsp; &nbsp; &nbsp; &nbsp; if err != nil {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; c <- Response{&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ErrCode: 1,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ErrMsg:"error",&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }()&nbsp; &nbsp; value := <-c}

Answer 2

您为跨越 go 例程而提供的函数在其签名中没有返回。Go 例程无法返回数据。运行 goroutine（异步）和从函数获取返回值本质上是矛盾的操作。简单地说，goroutine不知道在哪里返回数据。因此，它不允许这样做。你可以做这样的事情：var response Responsevar wg sync.WaitGroupwg.Add(1)go func() {&nbsp; &nbsp; defer wg.Done()&nbsp; &nbsp; res, err := example(a, b)&nbsp; &nbsp; if err != nil {&nbsp; &nbsp; &nbsp; &nbsp; response = res&nbsp; &nbsp; }}()wg.Wait()return response