C # Wlanapi.dll emettere ricevere la potenza del segnale

Question

Attualmente sto cercando di recuperare la potenza del segnale da un punto di accesso wireless utilizzando la chiamata WlanQueryInterface Wlanapi.dll.

Ecco la mia dichiarazione API

    [DllImport("wlanapi.dll", SetLastError = true)]
private static extern UInt32 WlanQueryInterface(IntPtr hClientHandle, ref Guid pInterfaceGuid, WLAN_INTF_OPCODE OpCode, IntPtr pReserved, out Int32 pdwDataSize, ref IntPtr ppData, IntPtr pWlanOpCodeValueType);

Il problema è quando guardo la voce wlanSignalStrength nella struttura WLAN_ASSOCIATION_ATTRIBUTES è impostato su 5400. documentazione di Microsoft API dice che dovrebbe essere un valore compreso tra 0 - 100.

Ecco la mia dichiarazione della struttura:

    /// <summary>
/// Structure contains association attributes for a connection.
/// </summary>
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct WLAN_ASSOCIATION_ATTRIBUTES
{
    /// <summary>
    /// A DOT11_SSID structure that contains the SSID of the association.
    /// </summary>
    public DOT11_SSID dot11Ssid;
    /// <summary>
    /// A DOT11_BSS_TYPE value that specifies whether the network is infrastructure or ad hoc.
    /// </summary>
    public DOT11_BSS_TYPE dot11BssType;
    /// <summary>
    /// A DOT11_MAC_ADDRESS that contains the BSSID of the association.
    /// </summary>
    public DOT11_MAC_ADDRESS dot11Bssid;
    /// <summary>
    /// A DOT11_PHY_TYPE value that indicates the physical type of the association
    /// </summary>
    public DOT11_PHY_TYPE dot11PhyType;
    /// <summary>
    /// The position of the DOT11_PHY_TYPE value in the structure containing the list of PHY types.
    /// </summary>
    public ulong uDot11PhyIndex;
    /// <summary>
    /// A percentage value that represents the signal quality of the network.
    /// </summary>
    public Int32 wlanSignalQuality;
    /// <summary>
    /// Contains the receiving rate of the association.
    /// </summary>
    public ulong ulRxRate;
    /// <summary>
    /// Contains the transmission rate of the association.
    /// </summary>
    public ulong ulTxRate;
}

Ecco la mia chiamata a WlanQueryInterface:

    Int32 iDataSize;
    IntPtr ppData = IntPtr.Zero;
    WLAN_CONNECTION_ATTRIBUTES wcaAttributes = new WLAN_CONNECTION_ATTRIBUTES();
    String[] sReturn = new String[4];

    if (WlanQueryInterface(pClientHandle, ref gInterfaceGUID, WLAN_INTF_OPCODE.wlan_intf_opcode_current_connection, IntPtr.Zero, out iDataSize, ref ppData, IntPtr.Zero) == ERROR_SUCCESS)
    {
        wcaAttributes = (WLAN_CONNECTION_ATTRIBUTES)Marshal.PtrToStructure(ppData, typeof(WLAN_CONNECTION_ATTRIBUTES));

        sReturn[0] = wcaAttributes.wlanAssociationAttributes.dot11Ssid.ucSSID;
        sReturn[1] = wcaAttributes.strProfileName;
        sReturn[2] = String.Format("{0:X2}-{1:X2}-{2:X2}-{3:X2}-{4:X2}-{5:X2}", wcaAttributes.wlanAssociationAttributes.dot11Bssid.bOne, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bTwo, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bThree, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bFour, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bFive, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bSix);
        sReturn[3] = wcaAttributes.wlanAssociationAttributes.wlanSignalQuality.ToString(); //This returns 5400 when the actual strength is ~99

        WlanFreeMemory(ppData);

        return sReturn;
    }
    else
    {
        throw new Exception("Unable to get interface connected SSID.");
    }

Qualcuno vedere quello che sto facendo male? Grazie in anticipo!

Answer 1

Finalmente ho riparato. Ho dovuto impostare il LayoutKind per le WLAN_ASSOCIATION_ATTRIBUTES di esplicitare e impostare il set di caratteri Unicode.

    [StructLayout(LayoutKind.Explicit, CharSet = CharSet.Unicode)]
private struct WLAN_ASSOCIATION_ATTRIBUTES
{
    /// <summary>
    /// A DOT11_SSID structure that contains the SSID of the association.
    /// </summary>
    [FieldOffset(0)]
    public DOT11_SSID dot11Ssid;
    /// <summary>
    /// A DOT11_BSS_TYPE value that specifies whether the network is infrastructure or ad hoc.
    /// </summary>
    [FieldOffset(0x24)]
    public DOT11_BSS_TYPE dot11BssType;
    /// <summary>
    /// A DOT11_MAC_ADDRESS that contains the BSSID of the association.
    /// </summary>
    [FieldOffset(40)]
    public DOT11_MAC_ADDRESS dot11Bssid;
    /// <summary>
    /// A DOT11_PHY_TYPE value that indicates the physical type of the association
    /// </summary>
    [FieldOffset(0x30)]
    public DOT11_PHY_TYPE dot11PhyType;
    /// <summary>
    /// The position of the DOT11_PHY_TYPE value in the structure containing the list of PHY types.
    /// </summary>
    [FieldOffset(0x34)]
    public ulong uDot11PhyIndex;
    /// <summary>
    /// A percentage value that represents the signal quality of the network.
    /// </summary>
    [FieldOffset(0x38)]
    public Int32 wlanSignalQuality;
    /// <summary>
    /// Contains the receiving rate of the association.
    /// </summary>
    [FieldOffset(60)]
    public ulong ulRxRate;
    /// <summary>
    /// Contains the transmission rate of the association.
    /// </summary>
    [FieldOffset(0x40)]
    public ulong ulTxRate;
}