如何将 GetProcAddress 与 JNA 一起使用?

Question

首先，我是JNA新手。我想通过java代码控制主板的LED照明。华硕为此提供了一个用C编写的SDK(C++？

他们的头文件看起来很简单：

#pragma once
#include <Windows.h>

typedef void* MbLightControl;
typedef void* GPULightControl;
typedef void* ClaymoreKeyboardLightControl;
typedef void* RogMouseLightControl;

typedef DWORD(WINAPI* EnumerateMbControllerFunc)(MbLightControl handles[], DWORD size);
typedef DWORD(WINAPI* SetMbModeFunc) (MbLightControl handle, DWORD mode);
typedef DWORD(WINAPI* SetMbColorFunc) (MbLightControl handle, BYTE* color, DWORD size);
typedef DWORD(WINAPI* GetMbColorFunc) (MbLightControl handle, BYTE* color, DWORD size);
typedef DWORD(WINAPI* GetMbLedCountFunc)(MbLightControl handle);
typedef DWORD(WINAPI* EnumerateGPUFunc)(GPULightControl handles[], DWORD size);
typedef DWORD(WINAPI* SetGPUModeFunc) (GPULightControl handle, DWORD mode);
typedef DWORD(WINAPI* SetGPUColorFunc) (GPULightControl handle, BYTE* color, DWORD size);
typedef DWORD(WINAPI* GetGPULedCountFunc)(GPULightControl handle);
typedef DWORD(WINAPI* CreateClaymoreKeyboardFunc)(ClaymoreKeyboardLightControl* handle);
typedef DWORD(WINAPI* SetClaymoreKeyboardModeFunc) (ClaymoreKeyboardLightControl handle, DWORD mode);
typedef DWORD(WINAPI* SetClaymoreKeyboardColorFunc) (ClaymoreKeyboardLightControl handle, BYTE* color, DWORD size);
typedef DWORD(WINAPI* GetClaymoreKeyboardLedCountFunc)(ClaymoreKeyboardLightControl handle);
typedef DWORD(WINAPI* CreateRogMouseFunc)(RogMouseLightControl* handle);
typedef DWORD(WINAPI* SetRogMouseModeFunc) (RogMouseLightControl handle, DWORD mode);
typedef DWORD(WINAPI* SetRogMouseColorFunc) (RogMouseLightControl handle, BYTE* color, DWORD size);
typedef DWORD(WINAPI* RogMouseLedCountFunc)(RogMouseLightControl handle);

我使用 JNA erator 来获取 JNA 映射，这是我得到的结果：

import com.ochafik.lang.jnaerator.runtime.LibraryExtractor;
import com.ochafik.lang.jnaerator.runtime.MangledFunctionMapper;
import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.NativeLibrary;
import com.sun.jna.Pointer;
import com.sun.jna.ptr.PointerByReference;
import com.sun.jna.win32.StdCallLibrary.StdCallCallback;
public interface Aura extends Library {
String JNA_LIBRARY_NAME = LibraryExtractor.getLibraryPath("AURA_SDK", true, Aura.class);
NativeLibrary JNA_NATIVE_LIB = NativeLibrary.getInstance(Aura.JNA_LIBRARY_NAME, MangledFunctionMapper.DEFAULT_OPTIONS);
Aura INSTANCE = (Aura) Native.loadLibrary(Aura.JNA_LIBRARY_NAME, Aura.class, MangledFunctionMapper.DEFAULT_OPTIONS);
interface EnumerateMbControllerFunc extends StdCallCallback {
int apply(PointerByReference handles, int size);
}
interface SetMbModeFunc extends StdCallCallback {
int apply(Pointer handle, int mode);
}
interface SetMbColorFunc extends StdCallCallback {
int apply(Pointer handle, Pointer color, int size);
}
interface GetMbColorFunc extends StdCallCallback {
int apply(Pointer handle, Pointer color, int size);
}
interface GetMbLedCountFunc extends StdCallCallback {
int apply(Pointer handle);
}
interface EnumerateGPUFunc extends StdCallCallback {
int apply(PointerByReference handles, int size);
}
interface SetGPUModeFunc extends StdCallCallback {
int apply(Pointer handle, int mode);
}
interface SetGPUColorFunc extends StdCallCallback {
int apply(Pointer handle, Pointer color, int size);
}
interface GetGPULedCountFunc extends StdCallCallback {
int apply(Pointer handle);
}
interface CreateClaymoreKeyboardFunc extends StdCallCallback {
int apply(PointerByReference handle);
}
interface SetClaymoreKeyboardModeFunc extends StdCallCallback {
int apply(Pointer handle, int mode);
}
interface SetClaymoreKeyboardColorFunc extends StdCallCallback {
int apply(Pointer handle, Pointer color, int size);
}
interface GetClaymoreKeyboardLedCountFunc extends StdCallCallback {
int apply(Pointer handle);
}
interface CreateRogMouseFunc extends StdCallCallback {
int apply(PointerByReference handle);
}
interface SetRogMouseModeFunc extends StdCallCallback {
int apply(Pointer handle, int mode);
}
interface SetRogMouseColorFunc extends StdCallCallback {
int apply(Pointer handle, Pointer color, int size);
}
interface RogMouseLedCountFunc extends StdCallCallback {
int apply(Pointer handle);
}
}

在示例C++代码中，他们使用 GetProcAddress 获取上述方法的地址，这样他们就可以调用它们：

HMODULE hLib = nullptr;
hLib = LoadLibraryA("AURA_SDK.dll");
(FARPROC&)EnumerateMbController = GetProcAddress(hLib, "EnumerateMbController");
DWORD _count = EnumerateMbController(NULL, 0);

我该如何对 JNA 执行相同的操作？

提前谢谢。

Answer 1

我不知道为什么头文件看起来像它们一样，但根据您提供的 C 示例，使用两个参数调用驻留在库AURA_SDK中的函数EnumerateMbController- 第一个是MbLightControl数组(这些是不透明的指针(，第二个是表示"大小"。

我会从上下文中推断：

• MbLightControl数组将接收指针
• 大小是您提供的数组的大小
• 函数的返回值将是实际返回的MbLightControl条目数

带有 NULL 的调用指示它将返回它将返回的 MbLightControl 实例数。

我对正确绑定的建议：

public interface Aura extends StdCallLibrary {
Aura INSTANCE = Native.loadLibrary("AURA_SDK", Aura.class, W32APIOptions.DEFAULT_OPTIONS);
public static class MbLightControl extends WinDef.PVOID {}
public int EnumerateMbController(MbLightControl[] handles, int size);
public int SetMbMode(MbLightControl handle, int mode);
public int SetMbColor(MbLightControl handle, byte[] color, int size);
public int GetMbColor(MbLightControl handle, byte[] color, int size);
public int GetMbLedCount(MbLightControl handle);
}

这将加载名为AURA_SDK的 dll，并使五个函数可访问。它还模仿MbLightControl头文件中的 typedef。DWORDs被绑定为java ints，以使调用更容易，因为java中的int总是32位，而Windows上的DWORD是相同的。

我不知道颜色代码的细节，但如果这些是 RGB LED，那么我假设每个 LED 将在字节数组中占用 3 个字节。

知道JNA使用LoadLibraryEx(LoadLibrary的老大哥(和GetProcAddress来加载函数可能会有所帮助。