我安裝了Golang，并在第一時間遇到了錯誤。go.mod file not found in current directory or any parent directory但是我正在研究目錄。go.mod不是只有在當前工作目錄位于GOPATH之外時才需要嗎？<GOPATH>/src以下是詳細信息圍棋版 ：go version go1.16.4 windows/amd64去 env ：set GO111MODULE=set GOARCH=amd64set GOBIN=set GOCACHE=C:\Users\<userName>\AppData\Local\go-buildset GOENV=C:\Users\<userName>\AppData\Roaming\go\envset GOEXE=.exeset GOFLAGS=set GOHOSTARCH=amd64set GOHOSTOS=windowsset GOINSECURE=set GOMODCACHE=C:\Users\<userName>\go\pkg\modset GONOPROXY=set GONOSUMDB=set GOOS=windowsset GOPATH=C:\Users\<userName>\goset GOPRIVATE=set GOPROXY=https://proxy.golang.org,directset GOROOT=C:\Program Files\Goset GOSUMDB=sum.golang.orgset GOTMPDIR=set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64set GOVCS=set GOVERSION=go1.16.4set GCCGO=gccgoset AR=arset CC=gccset CXX=g++set CGO_ENABLED=1set GOMOD=NULset CGO_CFLAGS=-g -O2set CGO_CPPFLAGS=set CGO_CXXFLAGS=-g -O2set CGO_FFLAGS=-g -O2set CGO_LDFLAGS=-g -O2set PKG_CONFIG=pkg-configset GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\<userName>\AppData\Local\Temp\go-build4258913208=/tmp/go-build -gno-record-gcc-switches工作目錄：C:\Users\<userName>\go\src\main.go法典：package mainimport "fmt"func main() {    fmt.Println("HELLO")}和錯誤：go: go.mod file not found in current directory or any parent directory; see 'go help modules'Build process exiting with code: 1 signal: nullp.s. 我正在使用VS Code