show-device.c

Displays the connected devices that can be used by libusbK.

show-device example:

1. Initializes a new LstK (device list) handle.
2. Gets the number of devices contained in the device list.
3. Demonstrates using LstK_FindByVidPid to locate the example VID/PID.
4. Demonstrates using LstK_MoveReset and LstK_MoveNext to locate the example VID/PID.
5. Demonstrates using LstK_Enumerate for printing a single line description of each device list element.
6. Frees the LstK (device list) handle created in step #1.

Console Output

USB\VID_04D8&PID_FA2E\LUSBW1: Benchmark Device (Travis Robinson)
Example device connected!

#include "examples.h"

// This function is called by the LstK_Enumerate function for each
// device until it returns FALSE.
static BOOL KUSB_API ShowDevicesCB(KLST_HANDLE DeviceList,
                                   KLST_DEVINFO_HANDLE deviceInfo,
                                   PVOID MyContext)
{
    // print some information about the device.
    printf("%04X:%04X (%s): %s - %s\n",
           deviceInfo->Common.Vid,
           deviceInfo->Common.Pid,
           deviceInfo->Common.InstanceID,
           deviceInfo->DeviceDesc,
           deviceInfo->Mfg);

    // If this function returns FALSE then enumeration ceases.
    return TRUE;
}

DWORD __cdecl main(int argc, char* argv[])
{
    KLST_HANDLE deviceList = NULL;
    KLST_DEVINFO_HANDLE deviceInfo = NULL;
    DWORD errorCode = ERROR_SUCCESS;
    ULONG count = 0;

    /*
    Initialize a new LstK (device list) handle.
    The list is polulated with all usb devices libusbK can access.
    */
    if (!LstK_Init(&deviceList, 0))
    {
        errorCode = GetLastError();
        printf("An error occured getting the device list. errorCode=%08Xh\n", errorCode);
        return errorCode;
    }

    // Get the number of devices contained in the device list.
    LstK_Count(deviceList, &count);
    if (!count)
    {
        printf("No devices connected.\n");

        // Always free the device list if LstK_Init returns TRUE
        LstK_Free(deviceList);

        return ERROR_DEVICE_NOT_CONNECTED;
    }

    /*
    There are three (3) ways to search the device list:
    - #1 LstK_FindByVidPid
    - #2 LstK_MoveReset, LstK_MoveNext, and LstK_Current
    - #3 LstK_Enumerate
    */

    // #1
    // Simple means of locating the fist device matching a vid/pid.
    //
    if (LstK_FindByVidPid(deviceList, EXAMPLE_VID, EXAMPLE_PID, &deviceInfo))
        printf("LstK_FindByVidPid: Example device connected!\n");
    else
        printf("Example device not found.\n");


    if (deviceInfo)
    {
        BOOL success = LibK_SetContext(deviceInfo, KLIB_HANDLE_TYPE_LSTINFOK, 1);
        if (success)
        {
            UINT_PTR myValue = LibK_GetContext(deviceInfo, KLIB_HANDLE_TYPE_LSTINFOK);
            printf("MyContextValue = %u\n", myValue);
        }

    }

    // #2
    // Enumerates the device list using it's internal "current" position.
    //
    // Reset the device list position.
    LstK_MoveReset(deviceList);
    //
    errorCode = ERROR_NO_MATCH;
    //
    // Call LstK_MoveNext after a LstK_MoveReset to advance to the first
    // element.
    while(LstK_MoveNext(deviceList, &deviceInfo))
    {
        if (deviceInfo->Common.Vid == EXAMPLE_VID &&
                deviceInfo->Common.Pid == EXAMPLE_PID)
        {
            errorCode = ERROR_SUCCESS;
            break;
        }
    }
    //
    // Report the connection state
    if (deviceInfo)
        printf("LstK_MoveNext: Example device connected!\n");
    else
        printf("Example device not found.\n");

    // #3
    // Enumerates the device list using the user supplied callback
    // function, ShowDevicesCB(). LstK_Enumerate calls this function for
    // each device info element until ShowDevicesCB(0 returns FALSE.
    //
    // Show all devices using the enumerate function.
    LstK_Enumerate(deviceList, ShowDevicesCB, NULL);

    // Free the device list
    LstK_Free(deviceList);

    // return the win32 error code.
    return errorCode;
}