Windows Character Mode Application 4

 

 

 

 

 

Reading Input Buffer Events Example

 

The ReadConsoleInput() function can be used to directly access a console's input buffer. When a console is created, mouse input is enabled and window input is disabled. To ensure that the process receives all types of events, this example uses the SetConsoleMode() function to enable window and mouse input. Then it goes into a loop that reads and handles 100 console input events. For example, the message "Keyboard event" is displayed when the user presses a key and the message "Mouse event" is displayed when the user interacts with the mouse.

Create a new empty Win32 console application project. Give a suitable project name and change the project location if needed.

Then, add the source file and give it a suitable name.

Next, add the following source code.

 

#include <windows.h>

#include <stdio.h>

 

// Prototypes

void ErrorExit(LPSTR);

void KeyEventProc(KEY_EVENT_RECORD);

void MouseEventProc(MOUSE_EVENT_RECORD);

void ResizeEventProc(WINDOW_BUFFER_SIZE_RECORD);

 

int wmain(int argc, WCHAR **argv)

{

    HANDLE hStdin;

    DWORD cNumRead, fdwMode, fdwSaveOldMode, i;

    INPUT_RECORD irInBuf[128];

    int counter=0;

 

    // Get the standard input handle.

    hStdin = GetStdHandle(STD_INPUT_HANDLE);

    if (hStdin == INVALID_HANDLE_VALUE)

        ErrorExit("GetStdHandle()");

      else

            wprintf(L"GetStdHandle() is OK!\n");

 

    // Save the current input mode, to be restored on exit.

    if (!GetConsoleMode(hStdin, &fdwSaveOldMode) )

        ErrorExit("GetConsoleMode()");

      else

            wprintf(L"GetConsoleMode() is OK!\n");

 

    // Enable the window and mouse input events.

    fdwMode = ENABLE_WINDOW_INPUT | ENABLE_MOUSE_INPUT;

    if (!SetConsoleMode(hStdin, fdwMode))

        ErrorExit("SetConsoleMode()");

      else

            wprintf(L"SetConsoleMode() is OK!\n");

 

    // Loop to read and handle the input events.

    while (counter++ <= 30)

    {

        // Wait for the events

        if (!ReadConsoleInput(

                hStdin,      // input buffer handle

                irInBuf,     // buffer to read into

                128,         // size of read buffer

                &cNumRead) ) // number of records read

            ErrorExit("ReadConsoleInput()");

            else

                  wprintf(L"ReadConsoleInput() is OK!\n");

 

        // Dispatch the events to the appropriate handler

        for (i = 0; i < cNumRead; i++)

        {

            switch(irInBuf[i].EventType)

            {

                case KEY_EVENT: // keyboard input

                    KeyEventProc(irInBuf[i].Event.KeyEvent);

                    break;

 

                case MOUSE_EVENT: // mouse input

                    MouseEventProc(irInBuf[i].Event.MouseEvent);

                    break;

 

                case WINDOW_BUFFER_SIZE_EVENT: // scrn buf. resizing

                    ResizeEventProc(irInBuf[i].Event.WindowBufferSizeEvent);

                    break;

 

                case FOCUS_EVENT:  // disregard focus events

 

                case MENU_EVENT:   // disregard menu events

                    break;

 

                default:

                    ErrorExit("Unknown event type");

                    break;

            }

        }

    }

    return 0;

}

 

void ErrorExit (LPSTR lpszMessage)

{

    fwprintf_s(stderr, L"%s\n", lpszMessage);

    ExitProcess(0);

}

 

void KeyEventProc(KEY_EVENT_RECORD ker)

{

    wprintf(L"  Key event: ");

 

    if(ker.bKeyDown)

        wprintf(L"key pressed!\n");

    else

            wprintf(L"key released!\n");

}

 

void MouseEventProc(MOUSE_EVENT_RECORD mer)

{

    wprintf(L"  Mouse event: ");

   

    switch(mer.dwEventFlags)

    {

        case 0:

            wprintf(L"button press!\n");

            break;

        case DOUBLE_CLICK:

            wprintf(L"double click!\n");

            break;

        case MOUSE_HWHEELED:

            wprintf(L"horizontal mouse wheel!\n");

            break;

        case MOUSE_MOVED:

            wprintf(L"mouse moved!\n");

            break;

        case MOUSE_WHEELED:

            wprintf(L"vertical mouse wheel!\n");

            break;

        default:

            wprintf(L"unknown\n");

            break;

    }

}

 

VOID ResizeEventProc(WINDOW_BUFFER_SIZE_RECORD wbsr)

{

    wprintf(L"Resize event!\n");

}

 

Build and run the project. Click, move and double click the mouse. The following screenshot is a sample output.

 

Reading Input Buffer Events Example: A sample console program output in action

 

 

 

 

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