獲取系統的網絡狀態與無線網的信號強度（格數）

一台電腦，有時通過有線網連接網絡（調制解調器/局域網），如有網卡也可連接wifi。
那么如何獲取WLAN是否連接，和相應的信號強度呢？

就以下倆點：

• 獲取電腦連網狀態
• 獲取無線網絡的信號強度

 獲取電腦連網狀態

通過IsNetworkAlive可獲取當前環境是否已經連接網絡。詳見《C# 獲取電腦的網絡連接狀態》

流程：網絡是否連接->是否有無線網連接->獲取無線網狀態（信號強度）->返回網絡狀態

[DllImport("sensapi.dll", SetLastError = true)]
private static extern bool IsNetworkAlive(out int connectionDescription);
public NetworkStatus GetNetworkStatusByNetworkAlive()
{
    var networkStatus = NetworkStatus.InternetWithError;

    int flags = 0;
    var isNetworkAlive = IsNetworkAlive(out flags);

    int errCode = Marshal.GetLastWin32Error();
    if (errCode != 0)
    {
        throw new InvalidOperationException($"通過{nameof(IsNetworkAlive)}非托管DLL，獲取網絡狀態時，遇到異常");
    }
    if (isNetworkAlive)
    {
        // 獲取WLAN網絡狀態
        var wlanStatus = GetWlanStatus();
        if (isNetworkAlive && wlanStatus == NetworkStatus.WifiWithErro)
        {
            networkStatus = NetworkStatus.Internet;
        }
        else
        {
            networkStatus = wlanStatus;
        }
    }
    return networkStatus;
}

 

網絡狀態枚舉值

暫時只定義了有線網和無線網的狀態 

    /// <summary>
    /// 網絡狀態
    /// </summary>
    public enum NetworkStatus
    {
        Internet,
        InternetWithError,
        WifiWithErro,
        WifiWithOneBar,
        WifiWithTwoBars,
        WifiWithThreeBars,
        WifiWithFourBars,
    }

那么，具體是否有線/還是無線網絡，如何判斷？見下面~

 

獲取無線網絡的信號強度

獲取WLAN的名稱與信號強度

無線網的信息，可以通過第三方開源ManagedWifi來獲取。

ManagedWifi.Dll也可以從我的雲盤下載：https://pan.baidu.com/s/1CjSUIMr0DuVqDZrdZCx_mA 密碼：2d2o

下載后引用到項目中

1. WlanClient wlanClient = new WlanClient();

2. 循環foreach(WlanClient.WlanInterface wlanIface in wlanClient.Interfaces)

3. Wlan.WlanAvailableNetwork[] networks = wlanIface.GetAvailableNetworkList(0);

值得注意的是,

• WlanClient只在有網卡的系統中能初始化--所以如果WlanClient不能初始化，且IsNetworkAlive返回true，則意味着當前是有線連接網線
• WlanInterfacer的GetAvailableNetworkList方法，獲取的是附近wifi熱點列表，和任務欄下熱點列表的順序無關。
• WlanAvailableNetwork的wlanSignalQuality信號強度，100以內，如要轉換成信號格數，需要整除25
• profileName，對已連接的熱點profileName顯示完整，未連接的熱點profileName為empty.

獲取無線網連接狀態：

private NetworkStatus GetWlanStatus()
{
    var wlanStatus = NetworkStatus.WifiWithErro;
    try
    {
        WlanClient wlanClient = new WlanClient();

        foreach (WlanClient.WlanInterface wlanIface in wlanClient.Interfaces)
        {
            if (wlanIface.InterfaceState == Wlan.WlanInterfaceState.Connected && wlanIface.CurrentConnection.isState == Wlan.WlanInterfaceState.Connected)
            {
                Wlan.WlanAvailableNetwork[] networks = wlanIface.GetAvailableNetworkList(0);
                foreach (var network in networks)
                {
                    if (network.profileName == wlanIface.CurrentConnection.profileName
                        && (int)network.flags == (int)(Wlan.WlanAvailableNetworkFlags.Connected | Wlan.WlanAvailableNetworkFlags.HasProfile))
                    {
                        switch (network.wlanSignalQuality / 25)
                        {
                            case 0:
                                wlanStatus = NetworkStatus.WifiWithOneBar;
                                break;
                            case 1:
                                wlanStatus = NetworkStatus.WifiWithTwoBars;
                                break;
                            case 2:
                                wlanStatus = NetworkStatus.WifiWithThreeBars;
                                break;
                            default:
                                wlanStatus = NetworkStatus.WifiWithFourBars;
                                break;
                        }
                        break;
                    }
                }
                break;
            }
        }
    }
    catch (Exception e)
    {
    }
    return wlanStatus;
}

 

關鍵字：網絡連接狀態NetworkStatus，無線網絡強度（格數），ManagedWifi，IsNetworkAlive，GetLastError