c# - 是否有 Windows 事件来查明蓝牙设备是否正在配对

Question

我正在构建一个允许我与蓝牙设备配对的应用程序。现在我正试图在 C# 中找到一个事件，它允许我检测何时添加或准备添加设备(请参阅 img:Windows 10 弹出窗口)

有人知道我要找哪个吗？

Answer 1

我有点晚了，但这里有一些关于我在普通 Raw API(C++ 中)中使用 WM_DEVICECHANGE 消息所做的事情的片段。

• 您需要拦截 WM_DEVICECHANGE 消息(显然)
• 您首先需要“注册”正确的 GUID:
• GUID_BTHPORT_DEVICE_INTERFACE {0850302A-B344-4fda-9BE9-90576B8D46F0} 拦截有关 radio 本身的事件
• GUID_BTH_DEVICE_INTERFACE {00F40965-E89D-4487-9890-87C3ABB211F4} 拦截有关任何蓝牙设备的事件和/或
• GUID_BLUETOOTHLE_DEVICE_INTERFACE{781aee18-7733-4ce4-add0-91f41c67b592} 拦截关于 BLE 的事件设备。

(这些是“界面 GUID”，以防您在 SetupAPIxx/CM_xx 例程中需要它们)

我正在使用以下代码来“注册”它们:

HDEVNOTIFY UDeviceInfoHandler::RegisterDeviceNotification(  HWND    hwnd,
                                                            GUID    InterfaceClassGuid,
                                                            DWORD   flags)
{
    DEV_BROADCAST_DEVICEINTERFACE DevFilter;
    ::ZeroMemory(&DevFilter, sizeof(DEV_BROADCAST_DEVICEINTERFACE) );
    DevFilter.dbcc_size = sizeof( DEV_BROADCAST_DEVICEINTERFACE );
    DevFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
    DevFilter.dbcc_classguid = InterfaceClassGuid;
    return ::RegisterDeviceNotification(hwnd,       //events recipient
                                        &DevFilter, //type of device
                                        flags);     //type of recipient handle
}

bool UDeviceInfoHandler::UnregisterDeviceNotification(HDEVNOTIFY hdevnotify)
{
    return TRUE==::UnregisterDeviceNotification(hdevnotify);
}

此时，您将能够

• 查看“ radio ”出现/消失(即通过在“设置”中选择“激活蓝牙”复选框)
• 查看 BT2.x 虚拟 COM 端口出现/消失
• 要查看 BLE 设备出现/消失，前提是它们已经“配对”(简而言之，已添加到注册表中)

通过处理

• DBT_DEVICEARRIVAL|DBT_DEVTYP_DEVICEINTERFACE 和
• DBT_DEVICEREMOVECOMPLETE|DBT_DEVTYP_DEVICEINTERFACE

WM_DEVICECHANGE 处理程序中的消息。

如果您需要访问与 radio /设备相关的 DBT_CUSTOMEVENT 消息，您首先需要为 WM_DEVICECHANGE 也“注册”一些“事件”，但要为 radio 的“HANDLE”注册。您可以注册以下事件的GUID

• GUID_BLUETOOTH_RADIO_IN_RANGE
• GUID_BLUETOOTH_RADIO_OUT_OF_RANGE
• GUID_BLUETOOTH_L2CAP_EVENT
• GUID_BLUETOOTH_HCI_EVENT
• GUID_BLUETOOTH_HCI_VENDOR_EVENT

使用类似的东西

void UBthDeviceInfoHandler::RegisterBthNotifications(HWND hwnd,const UGuidItems& guids)
{
    BLUETOOTH_FIND_RADIO_PARAMS radio_params;
    radio_params.dwSize = sizeof(BLUETOOTH_FIND_RADIO_PARAMS);

    HANDLE hRadio;
    HBLUETOOTH_RADIO_FIND hFind = BluetoothFindFirstRadio(&radio_params, &hRadio);
    if (hFind != INVALID_HANDLE_VALUE) 
    {
        do 
        {
            //for every events Guid you need
            HDEVNOTIFY hdevnotify=
                RegisterHandleNotification( hwnd,
                                            hRadio,
                                            Guid,
                                            DEVICE_NOTIFY_WINDOW_HANDLE);
            if (hdevnotify!=NULL){
                  //insert code here
            }
            else{
                  //error handling
            }
            //end for
        } while (BluetoothFindNextRadio(hFind, &hRadio));

        BluetoothFindRadioClose(hFind);
    }
}

此时，您将能够通过处理 WM_DEVICECHANGE 处理程序的 DBT_CUSTOMEVENT|DBT_DEVTYP_HANDLE 移植来接收这些事件，例如

    [...]
    #if (WINVER >= 0x040A)
            case DBT_CUSTOMEVENT:
            //@see https://msdn.microsoft.com/en-us/library/aa363217(v=vs.85).aspx
                if (lParam!=0){
                    PDEV_BROADCAST_HDR phdr = reinterpret_cast<PDEV_BROADCAST_HDR> (lParam);
                    switch (phdr->dbch_devicetype){
                        case DBT_DEVTYP_HANDLE:
                            {
            //@see https://learn.microsoft.com/en-us/windows/desktop/bluetooth/bluetooth-and-wm-devicechange-messages

                                //typedef struct _DEV_BROADCAST_HANDLE {
                                //  DWORD       dbch_size;
                                //  DWORD       dbch_devicetype;
                                //  DWORD       dbch_reserved;
                                //  HANDLE      dbch_handle;     // file handle used in call to RegisterDeviceNotification
                                //  HDEVNOTIFY  dbch_hdevnotify; // returned from RegisterDeviceNotification
                                //  //
                                //  // The following 3 fields are only valid if wParam is DBT_CUSTOMEVENT.
                                //  //
                                //  GUID        dbch_eventguid;
                                //  LONG        dbch_nameoffset; // offset (bytes) of variable-length string buffer (-1 if none)
                                //  BYTE        dbch_data[1];    // variable-sized buffer, potentially containing binary and/or text data
                                //} DEV_BROADCAST_HANDLE, *PDEV_BROADCAST_HANDLE;

                                PDEV_BROADCAST_HANDLE phndl=reinterpret_cast<PDEV_BROADCAST_HANDLE>(phdr);
                                CustomHandleEvent(*phndl);

                            }
                            break;


                  default:
                        break;
                }
            }//endif lParam!=0
            break;
    #endif // WINVER >= 0x040A

|dbch_eventguid|字段是 GUID_BLUETOOTH_RADIO_IN_RANGE 等事件之一。

好吧，这只是我迄今为止发现的内容的概述。不过，我们非常欢迎任何改进/建议/补充。我目前正在努力处理一些未记录的 CUSTOM_EVENTS，其 GUID 是

//When the Bluetooth radio handle is opened, call the RegisterDeviceNotification function and
//register for notifications on the handle using DBT_DEVTYP_HANDLE as the devicetype.
//When registered, the following GUIDs are sent, 
//and the DEV_BROADCAST_HANDLE::dbch_data member is the associated buffer.

//this unknow event happens while looking for nearby devices in Settings.
DEFINE_GUID(GUID_UNKNOWN_EVENT_GUID1,0x1BBD4010, 0x498C, 0x4E85, 0x85, 0x1B, 0xEA, 0xA0, 0x57, 0x15, 0xC3, 0x7A);

//
DEFINE_GUID(GUID_UNKNOWN_EVENT_GUID2,0xD4EB6503, 0xC001, 0x441A, 0xAE, 0x42, 0xEE, 0x0D, 0xC9, 0x6C, 0x18, 0x85);

//happening when opening Settings|Bluetooth panel
DEFINE_GUID(GUID_UNKNOWN_EVENT_GUID3,0x7A7637FF, 0x531C, 0x4205, 0x97, 0x80, 0x3F, 0x33, 0x5F, 0x65, 0xAD, 0xDD);
//nameoffset=-1 datalen=8

//Settings|Devices -> Bluetooth activation/deactivation
DEFINE_GUID(GUID_UNKNOWN_EVENT_GUID4,0xB74983CD, 0xC2D9, 0x4E38, 0xB8, 0x0E, 0x54, 0x72, 0xFC, 0x10, 0x8B, 0x4B);
//nameoffset=-1 datalen=8

希望这对您有所帮助!