Its been a very long time, I know. But rejoice! WeSeeTips is moving to its new home. Due to several personal and technical reasons, the migration was a bit delayed. Anyway, We will be back soon in new style and new tips to rock you. Keep your fingers crossed!

For WeSeeTips,
Jijo.

You can use Visual Studio IDE itself to generate XSD from XML file. Follow the steps.

1) Open the XML file in Visual Studio IDE.
2) Take View > Other Windows > Command Window.
3) Now type and execute command – XML.CreateSchema
4) See, the schema is generated.

A hidden pearl in VS IDE. Isn’t it?

Targeted Audience – Beginners.

But is there any PoorMan’s SearchSymbols without VisualAssist?

Did you forget about the hidden gem in VisualStudio find window? Yes, the Regular Expressions. You can use .* to do the same search done by VisualAssist. For instance, to do the above search, search for Show.*Msg. Have a look at following screenshots.

Now look at the results. Cool! isn’t it?

Quite easy. nah? BTW, did you try to kill that bug.

Targeted Audience – Beginners.

Background information
Pointer is a variable which holds the address of another variable. Where, function pointer is again a variable which holds the address of a function.

If you think pointers are evil, then function pointers must be Satan for you. Well, is there any easy way to create function pointers from function prototype? Indeed, there is. Its the “BAT” technique. Never heard about it before? No problem. Its invented by me just now. After watching BatMan series from cartoon network.

The “BAT” technique is this -

1. Put Bracket or parenthesis around the function name.
2. Add Asterisk or star in-front of function name.
3. Now Typedef it to create a new datatype. Means change the function name to new datatype name and add typedef infront of it.
4. Now you can use the new function pointer datatype like ordinary variables.

For instance, Assume we want to make a function pointer for function – DWORD MyFunction( int a, int b).

1) Bracket
DWORD (MyFunction)( int a, int b);

2) Asterisk
DWORD (*MyFunction)( int a, int b);

3) Typedef
typedef DWORD (*MyFunctionPtr)( int a, int b);

Ah! you have created a function pointer – MyFunctionPtr for function type – ‘DWORD MyFunction( int a, int b)’
Now you can use it like any other variable in your code. For instance, just see the following code snippet with real world usage of function pointers.

// Callback function for progress notification.
bool NotifyProgress( int Percentage )
{
 // Display progress and return true to continue.
 return true;
}

// typedef function pointer.
typedef bool (*NotifyProgressPtr)( int Percentage );

// DVD Burning function with pointer to NotifyProgress
// to update progress.
void BurnDVD( NotifyProgressPtr FnPtr )
{
 for( int Progress = 0; Progress <= 100; ++Progress )
 {
 // Call the function.
 (*FnPtr)(Progress);
 }
}

// Main function.
int _tmain(int argc, _TCHAR* argv[])
{
 // Ummm... Burn one DVD.
 BurnDVD( NotifyProgress );
 return 0;
}

Function pointers are not that much evil. Isn’t it?

Targeted Audience – Beginners.

You can use – SetWindowPos() with HWND_TOPMOST flag. Have a look at the code snippet.

void CRabbitDlg::OnSetTopmost()
{
    // Set window position to topmost window.
    ::SetWindowPos( GetSafeHwnd(),
                    HWND_TOPMOST,
                    0, 0, 0, 0,
                    SWP_NOMOVE | SWP_NOREDRAW | SWP_NOSIZE );
}

Single line of code. But wowing feature. isn’t it?

Targeted Audience – Beginners.

With great pleasure, I would like to inform you that – with god’s grace, I’ve been awarded as Microsoft MVP (Most Valuable Professional) for Visual C++. At this moment I would like to thank all my readers for supporting me and making this happen! Please go through my MVP profile.

I really thank Microsoft for this wonderful MVP award and I really love their products. I really feel great about being a part of it. Well, I owe all this achievements to my fellow readers who motivated me to post more and more and atlast ended in being an MVP. So hearty thanks to you all, once again!

Best Regards,
Jijo. [Humble VC++ enthusiasit from Next Door]

The secret is, visual C++ compiler passes this pointer via ECX register. So add (ClassName*)(@ECX) to watch window will give you this pointer. Have a look at the screenshot.

Interesting, the internals of Visual C++. Isn’t it?

Targeted Audiance – Intermediate.

Image Courtesy – Wallpaper Mania.

You can use the function – __cpuid(), which generates the instruction – cpuid. Have a look at the code snippet. Code taken and modified from MSDN.

#include <iostream>
#include <intrin.h>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
    // Get extended ids.
    int CPUInfo[4] = {-1};
    __cpuid(CPUInfo, 0x80000000);
    unsigned int nExIds = CPUInfo[0];

    // Get the information associated with each extended ID.
    char CPUBrandString[0x40] = { 0 };
    for( unsigned int i=0x80000000; i<=nExIds; ++i)
    {
        __cpuid(CPUInfo, i);

        // Interpret CPU brand string and cache information.
        if  (i == 0x80000002)
        {
            memcpy( CPUBrandString,
            CPUInfo,
            sizeof(CPUInfo));
        }
        else if( i == 0x80000003 )
        {
            memcpy( CPUBrandString + 16,
            CPUInfo,
            sizeof(CPUInfo));
        }
        else if( i == 0x80000004 )
        {
            memcpy(CPUBrandString + 32, CPUInfo, sizeof(CPUInfo));
        }
}

    cout << "Cpu String: " << CPUBrandString;
}

You can get a lot of information about cpu by using __cpuid. Have a look at the MSDN Documentation.

Targeted Audiance – Intermeidate.

Image Courtesy – marieforleo.com

Get the current DEVMODE by calling -EnumDisplaySettings(). Then change orientation by setting DEVMODE.dmDisplayOrientation and calling ChangeDisplaySettings(). Have a look at the code snippet. Code taken from MSDN.

// Get current Device Mode.
DEVMODE DeviceMode = { 0 };
EnumDisplaySettings( NULL,
 ENUM_CURRENT_SETTINGS,
 &DeviceMode );

// Change display mode upside down.
DeviceMode.dmDisplayOrientation = DMDO_180;
ChangeDisplaySettings( &DeviceMode, 0 );

// Sleep for 10 seconds.
Sleep( 10000 );

// Change display mode back.
DeviceMode.dmDisplayOrientation = DMDO_DEFAULT;
ChangeDisplaySettings( &DeviceMode, 0 );

Be careful to restore the display orientation back. Or else

Targeted Audiance – Intermeidate.

The first 4 bytes of an objects points to another pointer which points to virtual table. Casting it to DWORD*, we can parse all virtual functions. Once you get function address, you can get the function name by calling – SymFromAddr(). Have a look at code snippet.

#include <ImageHlp.h>
...
// Get list of virtual functions.
void CRabbitDlg::ParseVtable()
{
    // Initialize symbols.
    InitializeSymbols();

    // We are going to parse vtable of CWinApp object.
    DWORD* pBase = (DWORD*)(AfxGetApp());
    DWORD* pVptr = (DWORD*)*pBase;

    // Iterate through VirtualTable.
    DWORD Index = 0;
    DWORD FnAddr = pVptr[Index];
    while( FnAddr )
    {
        // Translate FunctionAddress to FunctionName.
        CString FunctionName;
        GetSymbolNameFromAddr( FnAddr, FunctionName );

        // Format and add to list.
        CString Final;
        Final.Format( _T("%0x - %s"), FnAddr, FunctionName.operator LPCTSTR());
        m_List.AddString( Final );

        // Next function pointer.
        FnAddr = pVptr[++Index];
    }
}

// Initialize Symbol engine.
void CRabbitDlg::InitializeSymbols()
{
    DWORD Options = SymGetOptions();
    Options |= SYMOPT_DEBUG;
    Options |= SYMOPT_UNDNAME; 

    ::SymSetOptions( Options ); 

    // Initialize symbols.
    ::SymInitialize ( GetCurrentProcess(),
                      NULL,
                      TRUE );
}

// Get symbol name from address.
void CRabbitDlg::GetSymbolNameFromAddr( DWORD SymbolAddress, CString& csSymbolName )
{
    DWORD64 Displacement = 0;
    SYMBOL_INFO_PACKAGE SymbolInfo = {0};
    SymbolInfo.si.SizeOfStruct  = sizeof( SYMBOL_INFO );
    SymbolInfo.si.MaxNameLen = sizeof(SymbolInfo.name);

    // Get symbol from address.
    ::SymFromAddr( GetCurrentProcess(),
                   SymbolAddress,
                   &Displacement,
                   &SymbolInfo.si );

    csSymbolName = SymbolInfo.si.Name;
}

Don’t forget to include ImageHlp.lib to project settings.

Targeted Audiance – Intermediate.

Picture Courtesy – Squidoo

You can use std::unique() algorithm to remove adjacent duplicate items. So at first, sort your data, then call std::unique(). Now all the duplicate data will be rearranged to end of container. Now delete the unwanted range of duplicate data. Have a look at code snippet below.

#include <vector>
#include <string>
#include <algorithm>

using namespace std;

int main(int argc, char* argv[])
{
    // Election list.
    vector<string> ElectionList;
    ElectionList.push_back( "Sam" );
    ElectionList.push_back( "John" );
    ElectionList.push_back( "Ron" );
    ElectionList.push_back( "Sam" );
    ElectionList.push_back( "John" );

    // Sort the list to make same items be together.
    sort( ElectionList.begin(), ElectionList.end());

    // Rearrange unique items to front.
    vector<string>::iterator Itr = unique(
        ElectionList.begin(),
        ElectionList.end());

    // Delete the duplicate range.
    ElectionList.erase( Itr, ElectionList.end());
}

Take care that std::unique() just removes the adjacent duplicate entries. It wont remove the entire duplicate entries present in the container. That’s why we need to sort the container at first, which will arrange all duplicate entries to adjacent  locations.

Targeted Audience – Beginners.

Image Courtesy – Flickr

The secret is, windows will choose the first icon present in executable as exe icon. By default for an MFC application, IDR_MAINFRAME will be the icon resource name and it have the lowest resource value – 128. Follow the steps to add an icon and make set it the first one in executable.

1. Import a new icon by using resource editor.

2. Let the icon be IDR_ICON1.
3. Now open resource.h and you can see, IDR_MAINFRAME which is the mfc icon, have lowest resource id.

4. Now edit the resource.h to make IDI_ICON1 as lowest resource id.

5. Now clean and build your application and check the application icon. Wow! its changed!!!

The point is, the icon should be the first icon in executable. You can set icon value even to zero. It will work!

Targeted Audiance – Intermediate.

You can use QueryPerformanceCounter(). You can get the performance counter frequency – i.e. ticks per second by calling QueryPerformanceFrequency(). Have a look at the sample CStopWatch class.

// Stop watch class.
class CStopWatch
{
public:
    // Constructor.
    CStopWatch()
    {
        // Ticks per second.
        QueryPerformanceFrequency( &liPerfFreq );
    }

    // Start counter.
    void Start()
    {
        liStart.QuadPart = 0;
        QueryPerformanceCounter( &liStart );
    }

    // Stop counter.
    void Stop()
    {
        liEnd.QuadPart = 0;
        QueryPerformanceCounter( &liEnd );
    }

    // Get duration.
    long double GetDuration()
    {
        return ( liEnd.QuadPart - liStart.QuadPart) /
                long double( liPerfFreq.QuadPart );
    }

private:
    LARGE_INTEGER liStart;
    LARGE_INTEGER liEnd;
    LARGE_INTEGER liPerfFreq;
};

int main()
{
    // Stop watch object.
    CStopWatch timer;

    // Start timer.
    timer.Start();

    // ZZzzzzz... for few seconds.
    Sleep( 3000 );
    timer.Stop();

    // Get the duration. Duration is in seconds.
    long double duration = timer.GetDuration();

    return 0;
}

Even if the sample app slept for 3 seconds, in high resolution timer, the duration is 2.9xxx seconds. Can you guess why?

Targeted Audiance – Intermediate.

Image Courtesy – reginadowntown.

Yes! You can use the api – SetConsoleTextAttribute(). See the code snippet below.

// Set text color as Yellow with white background.
SetConsoleTextAttribute(
    GetStdHandle( STD_OUTPUT_HANDLE ),
    FOREGROUND_INTENSITY              | // Set Text color
    FOREGROUND_RED | FOREGROUND_GREEN | // Text color as Yellow.
    BACKGROUND_INTENSITY              | // Set Background color
    BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE ); // White Bg.

Please note that you can mix red/green/blue constants to make new colors. Have fun.

Targeted Audience – Beginners.

Dear Visual C++ Enthusiasist,

Today is the first birthday of WeSeeTips. When i start this blog, my dream target was 1000 hits and at least 10-20 visitors per day. But at present, weseetips have 1,20,000 hits and more than 500~600 daily visits! Thanks a lot for making weseetips a grand success! All the credit goes to my fellow readers – that means you! Without you, this couldn’t be achieved. My sincere thanks to you all for reading weseetips and for keep watching! Lets grow together!

I would like to have a feedback from your side. About positives and negatives, points to improve, etc.. Kindly spend few seconds to drop some words! Please Help me to help you!

Very soon WeSeeTips will have a cosmetic change over! Well, whats it? Shhhhh! that’s a secret. Keep watching buddy, that day is not so far. Once again thanking you all,

For WeSeeTips,
Jijo.