我可以在下面从C中调用不带参数的Go函数。通过编译go build并打印
go build
Hello from Golang main function! CFunction says: Hello World from CFunction! Hello from GoFunction!
main.go
package main //extern int CFunction(); import "C" import "fmt" func main() { fmt.Println("Hello from Golang main function!") //Calling a CFunction in order to have C call the GoFunction C.CFunction(); } //export GoFunction func GoFunction() { fmt.Println("Hello from GoFunction!") }
文件1.c
#include <stdio.h> #include "_cgo_export.h" int CFunction() { char message[] = "Hello World from CFunction!"; printf("CFunction says: %s\n", message); GoFunction(); return 0; }
现在,我想将字符串/字符数组从C传递给GoFunction。
根据cgo文档中的 “对Go的C引用”,这是可能的,因此我向GoFunction添加了一个字符串参数,并将char数组传递message给GoFunction:
message
package main //extern int CFunction(); import "C" import "fmt" func main() { fmt.Println("Hello from Golang main function!") //Calling a CFunction in order to have C call the GoFunction C.CFunction(); } //export GoFunction func GoFunction(str string) { fmt.Println("Hello from GoFunction!") }
#include <stdio.h> #include "_cgo_export.h" int CFunction() { char message[] = "Hello World from CFunction!"; printf("CFunction says: %s\n", message); GoFunction(message); return 0; }
当go build我收到此错误:
./file1.c:7:14: error: passing 'char [28]' to parameter of incompatible type 'GoString' ./main.go:50:33: note: passing argument to parameter 'p0' here
其他参考:( https://blog.golang.org/c-go-cgo信誉不足,无法发布3个链接)根据上述博客文章的“字符串和事物”部分:“ Go和C字符串之间的转换是通过C.CString,C.GoString和C.GoStringN完成的。功能。” 但是这些是在Go中使用的,如果我想将字符串数据传递到Go中,则无济于事。
https://blog.golang.org/c-go-cgo
C中的字符串是a *C.char,而不是Go string。让导出的函数接受正确的C类型,并根据需要在Go中进行转换:
*C.char
string
//export GoFunction func GoFunction(str *C.char) { fmt.Println("Hello from GoFunction!") fmt.Println(C.GoString(str)) }