[TOC] ### 概述 ``` char --> C.char --> byte signed char --> C.schar --> int8 unsigned char --> C.uchar --> uint8 short int --> C.short --> int16 short unsigned int --> C.ushort --> uint16 int --> C.int --> int unsigned int --> C.uint --> uint32 long int --> C.long --> int32 or int64 long unsigned int --> C.ulong --> uint32 or uint64 long long int --> C.longlong --> int64 long long unsigned int --> C.ulonglong --> uint64 float --> C.float --> float32 double --> C.double --> float64 wchar_t --> C.wchar_t --> void * -> unsafe.Pointer ``` ## demo ``` package main /* #include <stdio.h> #include <stdlib.h> char ch = 'M'; unsigned char uch = 253; short st = 233; int i = 257; long lt = 11112222; float f = 3.14; double db = 3.15; void * p; char *str = "const string"; char str1[64] = "char array"; void printI(void *i) { printf("print i = %d\n", (*(int *)i)); } struct ImgInfo { char *imgPath; int format; unsigned int width; unsigned int height; }; void printStruct(struct ImgInfo *imgInfo) { if(!imgInfo) { fprintf(stderr, "imgInfo is null\n"); return ; } fprintf(stdout, "imgPath = %s\n", imgInfo->imgPath); fprintf(stdout, "format = %d\n", imgInfo->format); fprintf(stdout, "width = %d\n", imgInfo->width); } */ import "C" import ( "fmt" "reflect" "unsafe" ) func main() { fmt.Println("----------------Go to C---------------") fmt.Println(C.char('Y')) fmt.Printf("%c\n", C.char('Y')) fmt.Println(C.uchar('C')) fmt.Println(C.short(254)) fmt.Println(C.long(11112222)) var goi int = 2 // unsafe.Pointer --> void * cpi := unsafe.Pointer(&goi) C.printI(cpi) fmt.Println("----------------C to Go---------------") fmt.Println(C.ch) fmt.Println(C.uch) fmt.Println(C.st) fmt.Println(C.i) fmt.Println(C.lt) f := float32(C.f) fmt.Println(reflect.TypeOf(f)) fmt.Println(C.f) db := float64(C.db) fmt.Println(reflect.TypeOf(db)) fmt.Println(C.db) // 区别常量字符串和char数组，转换成Go类型不一样 str := C.GoString(C.str) fmt.Println(str) fmt.Println(reflect.TypeOf(C.str1)) var charray []byte for i := range C.str1 { if C.str1[i] != 0 { charray = append(charray, byte(C.str1[i])) } } fmt.Println(charray) fmt.Println(string(charray)) for i := 0; i < 10; i++ { imgInfo := C.struct_ImgInfo{imgPath: C.CString("../images/xx.jpg"), format: 0, width: 500, height: 400} defer C.free(unsafe.Pointer(imgInfo.imgPath)) C.printStruct(&imgInfo) } fmt.Println("----------------C Print----------------") } ```