如何在Go語言中呼叫DLL?
阿新 • • 發佈:2019-02-11
go語言通過syscall實現對作業系統的呼叫,從網上找了幾個例子,彙集如下:
關鍵程式碼共四行:
h := syscall.LoadLibrary("kernel32.dll")
proc := syscall.GetProcAddress(h, "GetVersion")
r := syscall.Syscall(uintptr(proc), 0, 0, 0, 0)
syscall.FreeLibrary(h)
完成整程式碼如下:
package main
import (
"syscall"
)
func main(){
h, err := syscall.LoadLibrary("kernel32.dll" )
if err != nil {
abort("LoadLibrary", err)
}
defer syscall.FreeLibrary(h)
proc, err := syscall.GetProcAddress(h, "GetVersion")
if err != nil {
abort("GetProcAddress", err)
}
r, _, _ := syscall.Syscall(uintptr(proc), 0, 0, 0, 0)
print_version(uint32(r))
}
func abort(funcname string, err error) {
panic(funcname + " failed: " + err.Error())
}
func print_version(v uint32) {
major := byte(v)
minor := uint8(v >> 8)
build := uint16(v >> 16)
print("windows version ", major, ".", minor, " (Build ", build, ")\n")
}
package main
import (
"fmt"
"syscall"
"time"
"unsafe"
)
const (
MB_OK = 0x00000000
MB_OKCANCEL = 0x00000001
MB_ABORTRETRYIGNORE = 0x00000002
MB_YESNOCANCEL = 0x00000003
MB_YESNO = 0x00000004
MB_RETRYCANCEL = 0x00000005
MB_CANCELTRYCONTINUE = 0x00000006
MB_ICONHAND = 0x00000010
MB_ICONQUESTION = 0x00000020
MB_ICONEXCLAMATION = 0x00000030
MB_ICONASTERISK = 0x00000040
MB_USERICON = 0x00000080
MB_ICONWARNING = MB_ICONEXCLAMATION
MB_ICONERROR = MB_ICONHAND
MB_ICONINFORMATION = MB_ICONASTERISK
MB_ICONSTOP = MB_ICONHAND
MB_DEFBUTTON1 = 0x00000000
MB_DEFBUTTON2 = 0x00000100
MB_DEFBUTTON3 = 0x00000200
MB_DEFBUTTON4 = 0x00000300
)
func abort(funcname string, err syscall.Errno) {
panic(funcname + " failed: " + err.Error())
}
var (
// kernel32, _ = syscall.LoadLibrary("kernel32.dll")
// getModuleHandle, _ = syscall.GetProcAddress(kernel32, "GetModuleHandleW")
user32, _ = syscall.LoadLibrary("user32.dll")
messageBox, _ = syscall.GetProcAddress(user32, "MessageBoxW")
)
func IntPtr(n int) uintptr {
return uintptr(n)
}
func StrPtr(s string) uintptr {
return uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(s)))
}
func MessageBox(caption, text string, style uintptr) (result int) {
ret, _, callErr := syscall.Syscall9(messageBox,
4,
0,
StrPtr(text),
StrPtr(caption),
style,
0, 0, 0, 0, 0)
if callErr != 0 {
abort("Call MessageBox", callErr)
}
result = int(ret)
return
}
//func GetModuleHandle() (handle uintptr) {
// if ret, _, callErr := syscall.Syscall(getModuleHandle, 0, 0, 0, 0); callErr != 0 {
// abort("Call GetModuleHandle", callErr)
// } else {
// handle = ret
// }
// return
//}
// windows下的另一種DLL方法呼叫
func ShowMessage2(title, text string) {
user32 := syscall.NewLazyDLL("user32.dll")
MessageBoxW := user32.NewProc("MessageBoxW")
MessageBoxW.Call(IntPtr(0), StrPtr(text), StrPtr(title), IntPtr(0))
}
func main() {
// defer syscall.FreeLibrary(kernel32)
defer syscall.FreeLibrary(user32)
//fmt.Printf("Retern: %d\n", MessageBox("Done Title", "This test is Done.", MB_YESNOCANCEL))
num := MessageBox("Done Title", "This test is Done.", MB_YESNOCANCEL)
fmt.Printf("Get Retrun Value Before MessageBox Invoked: %d\n", num)
ShowMessage2("windows下的另一種DLL方法呼叫", "HELLO !")
time.Sleep(3 * time.Second)
}
func init() {
fmt.Print("Starting Up\n")
}
獲取 Windows 的系統預設目錄
package main
import (
"fmt"
"syscall"
"unsafe"
)
var (
shell = syscall.MustLoadDLL("Shell32.dll")
getFolderPath = shell.MustFindProc("SHGetFolderPathW")
)
const (
CSIDL_DESKTOP = 0 //使用者桌面預設目錄
CSIDL_APPDATA = 26 //使用者AppData目錄
)
func main() {
b := make([]uint16, syscall.MAX_PATH)
// https://msdn.microsoft.com/en-us/library/windows/desktop/bb762181%28v=vs.85%29.aspx
// 這裡第二個引數CSIDL_A必須定義為const,否則編譯報錯
r, _, err := getFolderPath.Call(0, CSIDL_DESKTOP, 0, 0, uintptr(unsafe.Pointer(&b[0])))
if uint32(r) != 0 {
fmt.Sprintf("獲取DIR錯誤:", err)
}
a_dir := syscall.UTF16ToString(b)
r, _, err = getFolderPath.Call(0, CSIDL_APPDATA, 0, 0, uintptr(unsafe.Pointer(&b[0])))
if uint32(r) != 0 {
fmt.Sprintf("獲取DIR錯誤:", err)
}
b_dir := syscall.UTF16ToString(b)
fmt.Printf("目錄ID:%d 目錄地址:%s\n", CSIDL_DESKTOP, a_dir)
fmt.Printf("目錄ID:%d 目錄地址:%s\n", CSIDL_APPDATA, b_dir)
}
SHGetFolderPathW 的第二個引數必須定義為 const,否則編譯不過
輸出
目錄ID:0 目錄地址:C:\Users\kuuyee\Desktop
目錄ID:26 目錄地址:C:\Users\kuuyee\AppData\Roaming