基于C#实现的WiFi信号强度扫描程序

基于C#实现的WiFi信号强度扫描程序，信号强度检测、距离估算和实时监控功能：

---

一、核心功能实现

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.NetworkInformation;
using System.Runtime.InteropServices;
using System.Timers;
using SimpleWifi;

public class WifiScanner : IDisposable
{
    private Wifi _wifi;
    private Timer _scanTimer;
    private Dictionary<string, (int rssi, double distance)> _scanResults = new();

    public event EventHandler<ScanResultsUpdatedEventArgs> ResultsUpdated;

    public WifiScanner()
    {
        _wifi = new Wifi();
        InitializeScanTimer(5000); // 每5秒扫描一次
    }

    // 初始化定时扫描
    private void InitializeScanTimer(int interval)
    {
        _scanTimer = new Timer(interval);
        _scanTimer.Elapsed += async (s, e) => await ScanNetworks();
    }

    // 执行扫描操作
    private async Task ScanNetworks()
    {
        try
        {
            var accessPoints = await _wifi.GetAccessPointsAsync();
            var results = new List<ScanResult>();

            foreach (var ap in accessPoints)
            {
                if (ap.SignalStrength > -100) // 过滤无效信号
                {
                    double distance = CalculateDistance(ap.SignalStrength);
                    results.Add(new ScanResult
                    {
                        SSID = ap.Name,
                        RSSI = ap.SignalStrength,
                        Distance = distance,
                        Channel = ap.Channel,
                        Security = ap.IsSecure
                    });
                }
            }

            _scanResults = results.ToDictionary(x => x.SSID, x => (x.RSSI, x.Distance));
            ResultsUpdated?.Invoke(this, new ScanResultsUpdatedEventArgs(_scanResults.Values.ToList()));
        }
        catch (Exception ex)
        {
            HandleScanError(ex);
        }
    }

    // 信号强度转距离估算（经验公式）
    private double CalculateDistance(int rssi)
    {
        const double referenceDistance = 1.0; // 参考距离（米）
        const int referenceRSSI = -30;        // 参考信号强度

        if (rssi >= referenceRSSI) return 0.1; // 过近时返回固定值

        double pathLoss = referenceRSSI - rssi;
        return Math.Pow(10, pathLoss / 20) * referenceDistance;
    }

    // 显示结果
    public void DisplayResults()
    {
        Console.WriteLine("WiFi信号扫描结果:");
        foreach (var result in _scanResults.Values)
        {
            Console.WriteLine($"SSID: {result.SSID,-15} " +
                              $"信号强度: {result.RSSI}dBm " +
                              $"估算距离: {result.Distance.ToString("0.1f")}m " +
                              $"信道: {result.Channel} " +
                              $"加密: {(result.Security ? "是" : "否")}");
        }
    }

    // 释放资源
    public void Dispose()
    {
        _scanTimer?.Dispose();
        _wifi?.Dispose();
    }
}

public class ScanResult
{
    public string SSID { get; set; }
    public int RSSI { get; set; }
    public double Distance { get; set; }
    public int Channel { get; set; }
    public bool Security { get; set; }
}

public class ScanResultsUpdatedEventArgs : EventArgs
{
    public List<ScanResult> Results { get; }

    public ScanResultsUpdatedEventArgs(List<ScanResult> results)
    {
        Results = results;
    }
}

---

二、关键功能说明

1. 信号强度检测

// 获取所有可用网络
var accessPoints = await _wifi.GetAccessPointsAsync();

// 解析关键信息
foreach (var ap in accessPoints)
{
    Console.WriteLine($"SSID: {ap.Name}");
    Console.WriteLine($"信号强度: {ap.SignalStrength}%"); // 百分比强度
    Console.WriteLine($"实际dBm值: {ConvertToDbm(ap.SignalStrength)}dBm");
}

// 百分比转dBm转换方法
private int ConvertToDbm(int percentage)
{
    return (int)((percentage / 2.0) - 100);
}

2. 距离估算算法

// 改进型距离估算（考虑环境因素）
private double CalculateDistance(int rssi)
{
    const double txPower = -59; // 发射功率（dBm）
    const double n = 2.7;       // 路径损耗指数

    double ratio = rssi * 1.0 / txPower;
    if (ratio < 1) return Math.Pow(ratio, 10);
    else return 0.89976 * Math.Pow(ratio, 7.7095) + 0.111;
}

3. 实时监控界面（WinForm示例）

public partial class MainForm : Form
{
    private WifiScanner _scanner;
    private DataGridView _dataGridView;

    public MainForm()
    {
        InitializeComponent();
        InitializeComponents();
        _scanner = new WifiScanner();
        _scanner.ResultsUpdated += OnResultsUpdated;
    }

    private void InitializeComponents()
    {
        _dataGridView = new DataGridView { Dock = DockStyle.Fill };
        _dataGridView.Columns.AddRange(
            new DataGridViewTextBoxColumn { Name = "SSID", HeaderText = "网络名称" },
            new DataGridViewTextBoxColumn { Name = "SignalStrength", HeaderText = "信号强度(dBm)" },
            new DataGridViewTextBoxColumn { Name = "Distance", HeaderText = "估算距离(m)" }
        );
        Controls.Add(_dataGridView);
    }

    private void OnResultsUpdated(object sender, ScanResultsUpdatedEventArgs e)
    {
        _dataGridView.Invoke((MethodInvoker)delegate {
            _dataGridView.DataSource = e.Results;
        });
    }
}

---

三、工程实践要点

1. 权限配置

<!-- app.manifest -->
<requestedExecutionLevel level="requireAdministrator" uiAccess="false" />

2. 性能优化

• 批量扫描：合并多个扫描结果减少系统调用
• 数据缓存 ：使用ConcurrentDictionary存储历史数据
• 异步处理 ：采用async/await避免界面卡顿

3. 高级功能扩展

// 信道干扰分析
public Dictionary<int, int> GetChannelUtilization()
{
    return _scanResults.Values
        .GroupBy(x => x.Channel)
        .ToDictionary(g => g.Key, g => g.Count());
}

// 热力图生成
public Bitmap GenerateHeatmap()
{
    // 使用GDI+绘制信号强度分布
}

---

四、部署与使用

1. NuGet依赖

Install-Package SimpleWifi.netstandard.Lsh
Install-Package LiveCharts.WinForms

2. 运行示例

var scanner = new WifiScanner();
scanner.ResultsUpdated += (s, e) => 
{
    Console.WriteLine($"检测到 {e.Results.Count} 个网络");
    e.Results.OrderByDescending(r => r.SignalStrength).Take(3).ToList().ForEach(r => 
        Console.WriteLine($"最强信号: {r.SSID} ({r.SignalStrength}dBm)"));
};
scanner.StartContinuousScan();

---

五、调试与校准

1. 日志记录

public static class Logger
{
    public static void LogSignalData(int rssi, double distance)
    {
        File.AppendAllText("wifi_log.txt", 
            $"{DateTime.Now:yyyy-MM-dd HH:mm:ss} | RSSI:{rssi} | Distance:{distance}m\n");
    }
}

2. 精度校准

// 校准参数
private static double _calibrationFactor = 1.2;

// 带校准的距离计算
public double CalibratedDistance(int rssi)
{
    double rawDistance = CalculateDistance(rssi);
    return rawDistance * _calibrationFactor;
}

参考代码 WIFI Distance（Wifi信号强弱扫描程序） www.youwenfan.com/contentcsn/93530.html

六、界面增强建议

1. 信号强度可视化

   // 使用LiveCharts绘制实时波形
   var chart = new CartesianChart();
   chart.Series = new SeriesCollection
   {
       new LineSeries
       {
           Values = new ChartValues<double>(_scanResults.Values.Select(x => x.SignalStrength))
       }
   };

2. 设备定位功能

   public Point CalculatePosition()
   {
       // 三角定位算法实现
       var accessPoints = _scanResults.Values.ToList();
       if (accessPoints.Count < 3) return Point.Empty;
   
       // 实现三边测量算法...
   }