com.sun.jna.Pointer无法转换为com.sun.jna.platform.win32.WinDef.LPARAM

Question

Error:

error:com.sun.jna.Pointer connot be cast to com.sun.jna.platform.win32.WinDef.LPARAM error location:return User32.INSTANCE.CallNextHookEx(hHook, nCode, wParam, keyInfo.getPointer());

Code:

HMODULE hMod = Kernel32.INSTANCE.GetModuleHandle(null);

HOOKPROC lpfn = new LowLevelKeyboardProc()
{
    int count = 1;

    public LRESULT callback(int nCode, WPARAM wParam, KBDLLHOOKSTRUCT keyInfo)
    {
        System.out.println("nCode =" + nCode + ", wParam =" + wParam 
            + ", vkCode=" + keyInfo.vkCode);
        count++;

        if (count > 100)
        {
            quit = true;
        }

        return User32.INSTANCE.CallNextHookEx(hHook, nCode, wParam, keyInfo.getPointer());
    }
};

Answer 1

You need to manually construct the LPARAM from the pointer's value as seen in the JNA KeyHook example .

Pointer ptr = keyInfo.getPointer();
long peer = Pointer.nativeValue(ptr);
return User32.INSTANCE.CallNextHookEx(hHook, nCode, wParam, new LParam(peer));