Window keylistener

Question

Hi,
i wanna add a keylistener to the keyboard , i mean if i run my program it will listen to all the typed keys, ?
so can i put a keylistener on a window ? or is there a keylistener which listen only to the keyboard , even if my window is not selected ?
i hope u got me :)
thank you for your help

Answer 1

Hi,
I hope we can do that with JNI and KeyboardHooking.
this code worked fine when the aplication has the focus , but it didn't work when the applicaion is out of focus, i dont have any clue about that.
#include <stdio.h>
#include <windows.h>
#include "jni.h"
#include "JNIFrame.h"
#include <process.h>
//HINSTANCE hInst;
//HHOOK g_hook = NULL;
jclass cls1;
//jobject obj1;
JNIEnv *env1;
//JavaVM *pJavaVM;
jmethodID mid;
#pragma data_seg("Shared")
HHOOK g_hook = NULL;
HINSTANCE hInst = NULL;
JavaVM *pJavaVM = NULL;
jobject obj1 = NULL;
#pragma data_seg()
#pragma comment(linker,"/SECTION:Shared,RWS")
LRESULT CALLBACK KeyboardProc(int code, WPARAM wParam, LPARAM lParam);
int WINAPI DllMain(HINSTANCE hInstance, DWORD fdwReason, LPVOID lpvReserved);
int WINAPI DllMain(HINSTANCE hInstance, DWORD fdwReason, LPVOID lpvReserved)
hInst=hInstance;
return TRUE;
JNIEXPORT void JNICALL Java_JNIFrame_initialize(JNIEnv *env, jclass cls,jobject obj)
//jclass cls = (*env)->GetObjectClass(env, obj);
cls1=cls;
obj1=obj;
env1=env;
//g_hook = SetWindowsHookEx(WH_KEYBOARD,(HOOKPROC)KeyboardProc, hInst,(DWORD)NULL);
env->GetJavaVM(&pJavaVM);
mid = env->GetMethodID(cls, "callback", "()V");
g_hook = SetWindowsHookEx(WH_KEYBOARD,(HOOKPROC)KeyboardProc, hInst,(DWORD)NULL);
LRESULT CALLBACK KeyboardProc(
int nCode, // hook code
WPARAM wParam, // current-process flag
LPARAM lParam // address of structure with message data
JNIEnv *__env;
printf("sravan5");
#if defined(JDK1_2) || defined(JDK1_3)
pJavaVM->AttachCurrentThread((void**)&__env, (void*) 0);
#else
pJavaVM->AttachCurrentThread(&__env, (void*)0);
#endif
if(nCode>=0)
// jmethodID mid = __env->GetMethodID(cls1, "callback", "()V");
if (mid == 0) {
printf("sravan4");
return 0;
printf("sravan5");
__env->CallVoidMethod(obj1,mid);
return CallNextHookEx(g_hook, nCode, wParam, lParam);
JNIEXPORT void JNICALL Java_JNIFrame_unHook
(JNIEnv *, jclass, jobject)
UnhookWindowsHookEx(g_hook);