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AnswerRe: What is a WindowsFormsParkingWindow? Why does it kill my application? Pin
SimonS28-Nov-03 4:47
SimonS28-Nov-03 4:47 
GeneralScrolling TextBox or RichTextBox programmatically Pin
Radoslav Bielik28-Nov-03 3:43
Radoslav Bielik28-Nov-03 3:43 
GeneralRe: Scrolling TextBox or RichTextBox programmatically Pin
Heath Stewart28-Nov-03 7:39
protectorHeath Stewart28-Nov-03 7:39 
GeneralRe: Scrolling TextBox or RichTextBox programmatically Pin
Radoslav Bielik28-Nov-03 9:02
Radoslav Bielik28-Nov-03 9:02 
GeneralRe: Scrolling TextBox or RichTextBox programmatically Pin
obelisk2929-Nov-03 10:22
obelisk2929-Nov-03 10:22 
GeneralRe: Scrolling TextBox or RichTextBox programmatically Pin
obelisk2929-Nov-03 10:59
obelisk2929-Nov-03 10:59 
GeneralRe: Scrolling TextBox or RichTextBox programmatically Pin
Heath Stewart29-Nov-03 15:03
protectorHeath Stewart29-Nov-03 15:03 
GeneralHead off API functions Pin
lajiyo28-Nov-03 3:07
lajiyo28-Nov-03 3:07 
Hello every one:
I have a question about Head off API functions.
I have a article about it,but it is written with vc++.
I know that we can do it in vc++,but I want to do it in
C#,if I do this ,I have some questions about it .first:
there are some ASM in it,Secnod I can not write DLL like
vc++,here is the code,please help me .sorry for my poor English.



BOOL VirtualProtectEx(
HANDLE hProcess, // 要修改内存的进程句柄
LPVOID lpAddress, // 要修改内存的起始地址
DWORD dwSize, // 修改内存的字节
DWORD flNewProtect, // 修改后的内存属性
PDWORD lpflOldProtect // 修改前的内存属性的地址
);
BOOL WriteProcessMemory(
HANDLE hProcess, // 要写进程的句柄
LPVOID lpBaseAddress, // 写内存的起始地址
LPVOID lpBuffer, // 写入数据的地址
DWORD nSize, // 要写的字节数
LPDWORD lpNumberOfBytesWritten // 实际写入的子节数
);
BOOL ReadProcessMemory(
HANDLE hProcess, // 要读进程的句柄
LPCVOID lpBaseAddress, // 读内存的起始地址
LPVOID lpBuffer, // 读入数据的地址
DWORD nSize, // 要读入的字节数
LPDWORD lpNumberOfBytesRead // 实际读入的子节数
);

It is DLL here:


HHOOK g_hHook;
HINSTANCE g_hinstDll;
FARPROC pfMessageBoxA;
int WINAPI MyMessageBoxA(HWND hWnd, LPCTSTR lpText,LPCTSTR lpCaption,UINT uType);
BYTE OldMessageBoxACode[5],NewMessageBoxACode[5];
HMODULE hModule ;
DWORD dwIdOld,dwIdNew;
BOOL bHook=false;
void HookOn();
void HookOff();
BOOL init();
LRESULT WINAPI MousHook(int nCode,WPARAM wParam,LPARAM lParam);
BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
if(!init())
{
MessageBoxA(NULL,"Init","ERROR",MB_OK);
return(false);
}
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
if(bHook) UnintallHook();
break;
}
return TRUE;
}
LRESULT WINAPI Hook(int nCode,WPARAM wParam,LPARAM lParam)//空的钩子函数
{

return(CallNextHookEx(g_hHook,nCode,wParam,lParam));
}
HOOKAPI2_API BOOL InstallHook()//输出安装空的钩子函数
{
g_hinstDll=LoadLibrary("HookApi2.dll");
g_hHook=SetWindowsHookEx(WH_GETMESSAGE,(HOOKPROC)Hook,g_hinstDll,0);
if (!g_hHook)
{
MessageBoxA(NULL,"SET ERROR","ERROR",MB_OK);
return(false);
}


return(true);
}
HOOKAPI2_API BOOL UninstallHook()//输出御在钩子函数
{

return(UnhookWindowsHookEx(g_hHook));
}

BOOL init()//初始化得到MessageBoxA的地址,并生成Jmp XXX(MyMessageBoxA)的跳转指令
{
hModule=LoadLibrary("user32.dll");
pfMessageBoxA=GetProcAddress(hModule,"MessageBoxA");
if(pfMessageBoxA==NULL)
return false;
_asm
{
lea edi,OldMessageBoxACode
mov esi,pfMessageBoxA
cld
movsd
movsb
}
NewMessageBoxACode[0]=0xe9;//jmp MyMessageBoxA的相对地址的指令
_asm
{
lea eax,MyMessageBoxA
mov ebx,pfMessageBoxA
sub eax,ebx
sub eax,5
mov dword ptr [NewMessageBoxACode+1],eax
}
dwIdNew=GetCurrentProcessId(); //得到所属进程的ID
dwIdOld=dwIdNew;
HookOn();//开始拦截
return(true);
}

int WINAPI MyMessageBoxA(HWND hWnd, LPCTSTR lpText,LPCTSTR lpCaption, UINT uType )//首先关闭拦截,然后才能调用被拦截的Api 函数
{
int nReturn=0;
HookOff();
nReturn=MessageBoxA(hWnd,"Hook",lpCaption,uType);
HookOn();
return(nReturn);
}
void HookOn()
{
HANDLE hProc;
dwIdOld=dwIdNew;
hProc=OpenProcess(PROCESS_ALL_ACCESS,0,dwIdOld);//得到所属进程的句柄
VirtualProtectEx(hProc,pfMessageBoxA,5,PAGE_READWRITE,&dwIdOld);//修改所属进程中MessageBoxA的前5个字节的属性为可写
WriteProcessMemory(hProc,pfMessageBoxA,NewMessageBoxACode,5,0);//将所属进程中MessageBoxA的前5个字节改为JMP 到MyMessageBoxA
VirtualProtectEx(hProc,pfMessageBoxA,5,dwIdOld,&dwIdOld);//修改所属进程中MessageBoxA的前5个字节的属性为原来的属性
bHook=true;
}
void HookOff()//将所属进程中JMP MyMessageBoxA的代码改为Jmp MessageBoxA
{
HANDLE hProc;
dwIdOld=dwIdNew;
hProc=OpenProcess(PROCESS_ALL_ACCESS,0,dwIdOld);
VirtualProtectEx(hProc,pfMessageBoxA,5,PAGE_READWRITE,&dwIdOld);
WriteProcessMemory(hProc,pfMessageBoxA,OldMessageBoxACode,5,0);
VirtualProtectEx(hProc,pfMessageBoxA,5,dwIdOld,&dwIdOld);
bHook=false;
}
//测试文件:
int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{

if(!InstallHook())
{
MessageBoxA(NULL,"Hook Error!","Hook",MB_OK);
return 1;
}
MessageBoxA(NULL,"TEST","TEST",MB_OK);//可以看见Test变成了Hook,也可以在其他进程中看见
if(!UninstallHook())
{
MessageBoxA(NULL,"Uninstall Error!","Hook",MB_OK);
return 1;
}
return 0;
}

GeneralRe: Head off API functions Pin
Heath Stewart28-Nov-03 4:27
protectorHeath Stewart28-Nov-03 4:27 
GeneralRe: Head off API functions Pin
lajiyo28-Nov-03 23:11
lajiyo28-Nov-03 23:11 
GeneralRe: Head off API functions Pin
Heath Stewart29-Nov-03 14:54
protectorHeath Stewart29-Nov-03 14:54 
GeneralRe: Head off API functions Pin
leppie28-Nov-03 6:15
leppie28-Nov-03 6:15 
GeneralRe: Head off API functions Pin
lajiyo29-Nov-03 0:02
lajiyo29-Nov-03 0:02 
Generaladd OnPaint handler to a proj Pin
R. Thomas28-Nov-03 3:07
R. Thomas28-Nov-03 3:07 
GeneralRe: add OnPaint handler to a proj Pin
Heath Stewart28-Nov-03 4:23
protectorHeath Stewart28-Nov-03 4:23 
GeneralRe: add OnPaint handler to a proj Pin
R. Thomas28-Nov-03 4:36
R. Thomas28-Nov-03 4:36 
GeneralRe: add OnPaint handler to a proj Pin
Heath Stewart28-Nov-03 4:38
protectorHeath Stewart28-Nov-03 4:38 
GeneralDiable Font style and Size from Font Dialog Pin
Abhi158128-Nov-03 2:39
Abhi158128-Nov-03 2:39 
GeneralRe: Diable Font style and Size from Font Dialog Pin
Heath Stewart28-Nov-03 4:19
protectorHeath Stewart28-Nov-03 4:19 
Generalchanging image on picturebox in user control runtime Pin
Shailaja28-Nov-03 1:34
Shailaja28-Nov-03 1:34 
GeneralRe: changing image on picturebox in user control runtime Pin
Heath Stewart28-Nov-03 4:09
protectorHeath Stewart28-Nov-03 4:09 
GeneralRe: changing image on picturebox in user control runtime Pin
Shailaja1-Dec-03 1:22
Shailaja1-Dec-03 1:22 
GeneralRe: changing image on picturebox in user control runtime Pin
Heath Stewart1-Dec-03 2:02
protectorHeath Stewart1-Dec-03 2:02 
GeneralRe: changing image on picturebox in user control runtime Pin
Shailaja1-Dec-03 2:18
Shailaja1-Dec-03 2:18 
GeneralRe: changing image on picturebox in user control runtime Pin
Heath Stewart1-Dec-03 2:22
protectorHeath Stewart1-Dec-03 2:22 

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