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POKeyboardHookProc in DLL doesn't do anything when called from python
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  1. POKeyboardHookProc in DLL doesn't do anything when called from python
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    copied!<p>I've been trying to write a DLL in C.</p> <p>Install hook sets up the KeyboardProc. Calling the <code>InstallHook()</code> and <code>UninstallHook()</code> functions from Python always returns a 0, which I guess is because my callback function <code>KeyboardProc</code> isn't working.</p> <p>The following is my C code for the DLL:</p> <pre><code>#include "stdafx.h" #include &lt;windows.h&gt; #include &lt;string.h&gt; #include &lt;ctype.h&gt; #include &lt;stdio.h&gt; #include "ourdll.h" //#pragma comment(linker, "/SECTION:.SHARED,RWS") //#pragma data_seg(".SHARED") HHOOK hKeyboardHook = 0; int keypresses = 0; HMODULE hInstance = 0; //#pragma data_seg() BOOL WINAPI DllMain (HANDLE hModule, DWORD dwFunction, LPVOID lpNot) { hInstance = hModule; //Edit return TRUE; } LRESULT CALLBACK KeyboardProc(int hookCode, WPARAM vKeyCode, LPARAM flags) { if(hookCode &lt; 0) { return CallNextHookEx(hKeyboardHook, hookCode, vKeyCode, flags); } keypresses++;; return CallNextHookEx(hKeyboardHook, hookCode, vKeyCode, flags); } __declspec(dllexport) void InstallHook(void) { hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD, KeyboardProc, hInstance, 0); } __declspec(dllexport) int UninstallHook(void) { UnhookWindowsHookEx(hKeyboardHook); hKeyboardHook = 0; return keypresses; } </code></pre> <p>The Python code to use this is as follows:</p> <pre><code>&gt;&gt;&gt; from ctypes import * &gt;&gt;&gt; dll = CDLL('C:\...\OurDLL.dll') &gt;&gt;&gt; dll.InstallHook() </code></pre> <p>[Type something at this point]</p> <pre><code>&gt;&gt;&gt; result = dll.UninstallHook() &gt;&gt;&gt; result 0 </code></pre> <p>EDIT: I should probably mention that I've also tried out a <code>LowLevelKeyboardHook</code>. I understand that the LowLevel hook is global and will catch all keystrokes, but that just caused my <code>dll.InstallHook()</code> Python code to freeze for a second or two before returning zero.</p> <p>I am no expert in C, so any help would be greatly appreciated. Thanks.</p>
 

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