Feature: Improve bandwidth meter & fix bugs

Source/NETworkManager.Converters/BandwidthBytesToSpeedConverter.cs

@@ -1,21 +1,31 @@
-using System;
+using System;
 using System.Globalization;
 using System.Windows.Data;
 using NETworkManager.Utilities;
 
 namespace NETworkManager.Converters;
 
+/// <summary>
+/// Converts a byte-per-second value to a human-readable speed string.
+/// Pass the converter parameter "bytes" to format as byte/s (e.g. "1.54 MB/s");
+/// any other value (default) formats as bit/s (e.g. "12.3 Mbit/s") to match the chart axis.
+/// </summary>
 public sealed class BandwidthBytesToSpeedConverter : IValueConverter
 {
     public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
     {
-        return value != null
-            ? $"{FileSizeConverter.GetBytesReadable((long)value * 8)}it/s ({FileSizeConverter.GetBytesReadable((long)value)}/s)"
-            : "-/-";
+        if (value == null)
+            return "-/-";
+
+        var bytesPerSecond = (long)value;
+
+        return parameter as string == "bytes"
+            ? $"{FileSizeConverter.GetBytesReadable(bytesPerSecond)}/s"
+            : $"{FileSizeConverter.GetBytesReadable(bytesPerSecond * 8)}it/s";
     }
 
     public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
-}
+}

Source/NETworkManager.Converters/BytesToExactStringConverter.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Globalization;
+using System.Windows.Data;
+using NETworkManager.Localization.Resources;
+
+namespace NETworkManager.Converters;
+
+/// <summary>
+/// Converts a byte count to its exact value with thousands separators and a "Bytes" unit
+/// (e.g. "6,783,176,192 Bytes"). Intended for tooltips that complement a human-readable size.
+/// </summary>
+public sealed class BytesToExactStringConverter : IValueConverter
+{
+    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        return value != null ? string.Format(culture, "{0:N0} {1}", (long)value, Strings.Bytes) : "-/-";
+    }
+
+    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        throw new NotImplementedException();
+    }
+}

Source/NETworkManager.Documentation/DocumentationManager.cs

@@ -255,6 +255,7 @@ public static DocumentationIdentifier GetIdentifierBySettingsName(SettingsName n
             SettingsName.Profiles => DocumentationIdentifier.SettingsProfiles,
             SettingsName.Settings => DocumentationIdentifier.SettingsSettings,
             SettingsName.Dashboard => GetIdentifierByApplicationName(ApplicationName.Dashboard),
+            SettingsName.NetworkInterface => GetIdentifierByApplicationName(ApplicationName.NetworkInterface),
             SettingsName.IPScanner => GetIdentifierByApplicationName(ApplicationName.IPScanner),
             SettingsName.PortScanner => GetIdentifierByApplicationName(ApplicationName.PortScanner),
             SettingsName.PingMonitor => GetIdentifierByApplicationName(ApplicationName.PingMonitor),

Source/NETworkManager.Models/Network/BandwidthMeter.cs

@@ -1,5 +1,7 @@
-using System;
+using System;
+using System.Diagnostics;
 using System.Linq;
+using System.Net.NetworkInformation;
 using System.Windows.Threading;
 
 namespace NETworkManager.Models.Network;
@@ -30,6 +32,12 @@ private void Timer_Tick(object sender, EventArgs e)
 
     #region Variables
 
+    /// <summary>
+    /// The default sample interval in milliseconds. Kept as a constant because the speed
+    /// calculation and the consuming view model derive timing from it.
+    /// </summary>
+    public const double DefaultUpdateInterval = 1000;
+
     public double UpdateInterval
     {
         get;
@@ -42,12 +50,13 @@ public double UpdateInterval
 
             field = value;
         }
-    } = 1000;
+    } = DefaultUpdateInterval;
 
     public bool IsRunning => _timer.IsEnabled;
 
     private readonly DispatcherTimer _timer = new();
     private readonly System.Net.NetworkInformation.NetworkInterface _networkInterface;
+    private readonly Stopwatch _stopwatch = new();
     private long _previousBytesSent;
     private long _previousBytesReceived;
     private bool _canUpdate; // Collect initial data for correct calculation
@@ -76,34 +85,60 @@ public void Stop()
     {
         _timer.Stop();
 
-        // Reset
+        // Reset, so the next sample re-seeds the baseline (avoids a speed spike after a pause).
         _canUpdate = false;
     }
 
     private void Update()
     {
-        var stats = _networkInterface.GetIPv4Statistics();
+        // The interface may have been removed/disabled after this meter was created.
+        if (_networkInterface == null)
+            return;
 
-        var totalBytesSent = stats.BytesSent;
-        var totalBytesReceived = stats.BytesReceived;
+        IPInterfaceStatistics stats;
 
-        var byteSentSpeed = totalBytesSent - _previousBytesSent;
-        var byteReceivedSpeed = totalBytesReceived - _previousBytesReceived;
+        try
+        {
+            // IPStatistics covers both IPv4 and IPv6 traffic on the interface.
+            stats = _networkInterface.GetIPStatistics();
+        }
+        catch (NetworkInformationException)
+        {
+            // Transient failure (e.g. adapter going down) - skip this tick.
+            return;
+        }
 
-        _previousBytesSent = stats.BytesSent;
-        _previousBytesReceived = stats.BytesReceived;
+        var totalBytesSent = stats.BytesSent;
+        var totalBytesReceived = stats.BytesReceived;
 
-        // Need to collect initial data for correct calculation...
+        // First sample after start/resume: seed the baseline and start timing, no speed yet.
         if (!_canUpdate)
         {
+            _previousBytesSent = totalBytesSent;
+            _previousBytesReceived = totalBytesReceived;
+            _stopwatch.Restart();
             _canUpdate = true;
 
             return;
         }
 
-        OnUpdateSpeed(new BandwidthMeterSpeedArgs(DateTime.Now, totalBytesReceived, totalBytesSent, byteReceivedSpeed,
-            byteSentSpeed));
+        var elapsedSeconds = _stopwatch.Elapsed.TotalSeconds;
+        _stopwatch.Restart();
+
+        // Clamp negative deltas: cumulative counters can reset/wrap (driver reset, disable/enable).
+        var deltaSent = Math.Max(0, totalBytesSent - _previousBytesSent);
+        var deltaReceived = Math.Max(0, totalBytesReceived - _previousBytesReceived);
+
+        // Derive a true per-second rate from the measured elapsed time (robust against timer jitter).
+        var byteSentSpeed = elapsedSeconds > 0 ? (long)(deltaSent / elapsedSeconds) : 0;
+        var byteReceivedSpeed = elapsedSeconds > 0 ? (long)(deltaReceived / elapsedSeconds) : 0;
+
+        _previousBytesSent = totalBytesSent;
+        _previousBytesReceived = totalBytesReceived;
+
+        OnUpdateSpeed(new BandwidthMeterSpeedArgs(DateTime.Now, totalBytesReceived, totalBytesSent,
+            byteReceivedSpeed, byteSentSpeed));
     }
 
     #endregion
-}
+}

Source/NETworkManager.Settings/GlobalStaticConfiguration.cs

@@ -104,6 +104,7 @@ public static class GlobalStaticConfiguration
 
     // Application: Network Interface
     public static ExportFileType NetworkInterface_ExportFileType => ExportFileType.Csv;
+    public static int NetworkInterface_BandwidthChartTime => 60;
 
     // Application: WiFi
     public static bool WiFi_Show2dot4GHzNetworks => true;

Source/NETworkManager.Settings/SettingsInfo.cs

@@ -894,6 +894,22 @@ public ExportFileType NetworkInterface_ExportFileType
         }
     } = GlobalStaticConfiguration.NetworkInterface_ExportFileType;
 
+    /// <summary>
+    /// Gets or sets the bandwidth chart time window in seconds.
+    /// </summary>
+    public int NetworkInterface_BandwidthChartTime
+    {
+        get;
+        set
+        {
+            if (value == field)
+                return;
+
+            field = value;
+            OnPropertyChanged();
+        }
+    } = GlobalStaticConfiguration.NetworkInterface_BandwidthChartTime;
+
     #endregion
 
     #region WiFi

Source/NETworkManager.Settings/SettingsName.cs

@@ -14,6 +14,7 @@ public enum SettingsName
     Profiles,
     Settings,
     Dashboard,
+    NetworkInterface,
     IPScanner,
     PortScanner,
     PingMonitor,

Source/NETworkManager.Settings/SettingsViewManager.cs

@@ -48,6 +48,8 @@ public static class SettingsViewManager
         // Applications
         new(SettingsName.Dashboard, ApplicationManager.GetIcon(ApplicationName.Dashboard),
             SettingsGroup.Application),
+        new(SettingsName.NetworkInterface, ApplicationManager.GetIcon(ApplicationName.NetworkInterface),
+            SettingsGroup.Application),
         new(SettingsName.IPScanner, ApplicationManager.GetIcon(ApplicationName.IPScanner),
             SettingsGroup.Application),
         new(SettingsName.PortScanner, ApplicationManager.GetIcon(ApplicationName.PortScanner),

Source/NETworkManager/Controls/LiveChartsBandwidthTooltip.xaml

@@ -0,0 +1,46 @@
+<UserControl x:Class="NETworkManager.Controls.LiveChartsBandwidthTooltip"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             mc:Ignorable="d">
+    <Border Background="{DynamicResource MahApps.Brushes.Window.Background}"
+            BorderBrush="{DynamicResource MahApps.Brushes.Gray8}"
+            BorderThickness="1">
+        <Grid Margin="10">
+            <Grid.RowDefinitions>
+                <RowDefinition Height="Auto" />
+                <RowDefinition Height="10" />
+                <RowDefinition Height="Auto" />
+            </Grid.RowDefinitions>
+            <TextBlock Grid.Row="0" Grid.Column="0"
+                       Style="{StaticResource InfoTextBlock}"
+                       HorizontalAlignment="Center"
+                       Text="{Binding HeaderText}" />
+            <ItemsControl Grid.Row="2" Grid.Column="0"
+                          ItemsSource="{Binding TooltipEntries}">
+                <ItemsControl.ItemTemplate>
+                    <DataTemplate>
+                        <Grid>
+                            <Grid.ColumnDefinitions>
+                                <ColumnDefinition Width="Auto" />
+                                <ColumnDefinition Width="10" />
+                                <ColumnDefinition Width="Auto" />
+                                <ColumnDefinition Width="10" />
+                                <ColumnDefinition Width="Auto" />
+                            </Grid.ColumnDefinitions>
+                            <Rectangle Grid.Column="0" Height="2" Width="14"
+                                       Fill="{Binding SeriesColor}" />
+                            <TextBlock Grid.Column="2" Text="{Binding Value}"
+                                       Style="{StaticResource DefaultTextBlock}"
+                                       VerticalAlignment="Center" Foreground="{DynamicResource MahApps.Brushes.Gray3}" />
+                            <TextBlock Grid.Column="4" Text="{Binding SeriesName}"
+                                       Style="{StaticResource AccentTextBlock}"
+                                       VerticalAlignment="Center" />
+                        </Grid>
+                    </DataTemplate>
+                </ItemsControl.ItemTemplate>
+            </ItemsControl>
+        </Grid>
+    </Border>
+</UserControl>