Golang下通过syscall调用win32的api

syscall.Syscallsyscall.Syscall6syscall.Syscall9syscall.Syscall12syscall.Syscall15

syscall.Syscall(trap, nargs, a1, a2, a3)

//首先,准备输入参数, GetDiskFreeSpaceEx需要4个参数, 可查MSDNdir := "C:"lpFreeBytesAvailable := int64(0) //注意类型需要跟API的类型相符lpTotalNumberOfBytes := int64(0)
lpTotalNumberOfFreeBytes := int64(0)//获取方法的引用kernel32, err := syscall.LoadLibrary("Kernel32.dll") // 严格来说需要加上 defer syscall.FreeLibrary(kernel32)GetDiskFreeSpaceEx, err := syscall.GetProcAddress(syscall.Handle(kernel32), "GetDiskFreeSpaceExW")//执行之. 因为有4个参数,故取Syscall6才能放得下. 最后2个参数,自然就是0了r, _, errno := syscall.Syscall6(uintptr(GetDiskFreeSpaceEx), 4,
            uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr("C:"))),
            uintptr(unsafe.Pointer(&lpFreeBytesAvailable)),
            uintptr(unsafe.Pointer(&lpTotalNumberOfBytes)),
            uintptr(unsafe.Pointer(&lpTotalNumberOfFreeBytes)), 0, 0)            // 注意, errno并非error接口的, 不可能是nil// 而且,根据MSDN的说明,返回值为0就fail, 不为0就是成功if r != 0 {
    log.Printf("Free %dmb", lpTotalNumberOfFreeBytes/1024/1024)
}

    h := syscall.MustLoadDLL("kernel32.dll")
    c := h.MustFindProc("GetDiskFreeSpaceExW")
    lpFreeBytesAvailable := int64(0)
    lpTotalNumberOfBytes := int64(0)
    lpTotalNumberOfFreeBytes := int64(0)
    r2, _, err := c.Call(uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr("F:"))),
        uintptr(unsafe.Pointer(&lpFreeBytesAvailable)),
        uintptr(unsafe.Pointer(&lpTotalNumberOfBytes)),
        uintptr(unsafe.Pointer(&lpTotalNumberOfFreeBytes)))    if r2 != 0 {
        log.Println(r2, err, lpFreeBytesAvailable/1024/1024)
    }