Fixed a memory leak in the WPF project

Audio Router UWP/Audio Router/MainPage.xaml.cs

@@ -147,6 +147,8 @@ namespace Audio_Router
                         InputAudioComboBox.Items.Add(sourceDevices[i].Name);
                     }
                 }
+
+                // Set output device & add to inputs too
                 for (int i = 0; i < targetDevices.Count; i++)
                 {
                     if(targetDevices[i].Id == defaultOutput.Id)
@@ -211,7 +213,6 @@ namespace Audio_Router
                 };
                 result = await AudioGraph.CreateAsync(settings);
                 ag = result.Graph;
-
                 if (result.Status != AudioGraphCreationStatus.Success)
                 {
                     return;

Audio Router WPF/AudioGraphConnection.cs

@@ -25,10 +25,11 @@ namespace Audio_Router_WPF
 
         Dispatcher uiDispatcher { get; set; }
 
-        TextBlock latencyLabel { get; set; }
+        TextBlock latencyLabel { get; set; } = new TextBlock();
 
-        int quantaCount = 0;
+        int quantaCount;
 
+#pragma warning disable CS8618 // Cannot convert null literal to non-nullable reference type.
         public AudioGraphConnection(AudioGraph graph, AudioDeviceOutputNode targetDevice, AudioDeviceInputNode sourceDevice, Dispatcher uiDispatcher)
         {
             Graph = graph;
@@ -128,23 +129,43 @@ namespace Audio_Router_WPF
         private void Graph_QuantumProcessed(AudioGraph sender, object args)
         {
             // updates aren't urgent, only process after some time (this is 1s, with the Windows default of 10 ms / quanta
-            if (quantaCount++ == 100)
+            if (quantaCount % 100 == 0)
             {
-                string result = (Graph.LatencyInSamples / (double)Graph.SamplesPerQuantum * SamplesPerMS).ToString("0.#") + " ms";
                 if (latencyLabel is null) return;
+                string result = (Graph.LatencyInSamples / (double)Graph.SamplesPerQuantum * SamplesPerMS).ToString("0.#") + " ms";
+                
                 uiDispatcher.Invoke(() =>
                  {
                      try
                      {
+                         // Try to set the label, otherwise it may have already been destroyed
                          latencyLabel.Text = result;
                      }
-                     catch
+                     catch (NullReferenceException)
                      {
 
                      }
                  }, DispatcherPriority.Background);
-                quantaCount = 0;
+                result = null;
             }
+            /// ----------------------
+            /// ||    About this:   ||
+            /// ----------------------
+            /// Running AudioGraph in WPF causes what seems to be the captured audio data to 
+            /// never go out of scope (this does not happen in UWP, as shown in the near-identical code from the 
+            /// UWP project), so the memory allocations for the project keep increasing.
+            /// Stopping the AudioGraph causes these allocations to finalise, so frees up the space.
+            /// we can call ResetAllNodes() periodically (i.e.: every 10s (1000 * 10 ms)) to reset the
+            /// nodes
+            ///
+            if (quantaCount == 1000)
+            {
+                //SourceDevice.Reset();
+                Graph.ResetAllNodes();
+                // GC.Collect(); // We can let the GC handle itself
+            }
+            quantaCount++;
+            quantaCount %= 1001;
         }
 
         private void VolumeSlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
@@ -153,10 +174,12 @@ namespace Audio_Router_WPF
             SourceDevice.OutgoingGain = e.NewValue;
         }
 
+        #pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
         private void DestroyButton_Click(object sender, RoutedEventArgs e)
         {
-            latencyLabel = null;
             Graph.QuantumProcessed -= Graph_QuantumProcessed;
+            Graph.ResetAllNodes();
+            latencyLabel = null;
             Graph.Stop();
             TargetDevice.Dispose();
             SourceDevice.Dispose();
@@ -172,6 +195,7 @@ namespace Audio_Router_WPF
         public void OnHide()
         {
             latencyLabel = null;
+            Graph.QuantumProcessed -= Graph_QuantumProcessed;
         }
     }
 }

Audio Router WPF/MainWindow.xaml

@@ -5,7 +5,7 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:Audio_Router_WPF"
         mc:Ignorable="d"
-        Title="MainWindow" Height="450" Width="800">
+        Title="Audio Router WPF" Height="450" Width="800">
     <Grid VerticalAlignment="Stretch">
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto"/>
@@ -18,10 +18,10 @@
             <TextBlock Text="Input Audio Device:" TextWrapping="Wrap" Margin="0,10,0,0" Foreground="White" HorizontalAlignment="Center"/>
             <ComboBox x:Name="InputAudioComboBox" MinWidth="500" HorizontalAlignment="Center"/>
             <TextBlock Text="Output Audio Device:" TextWrapping="Wrap" Margin="0,10,0,0" Foreground="White" HorizontalAlignment="Center"/>
-            <ComboBox x:Name="OutputAudioComboBox" MinWidth="500" HorizontalAlignment="Center"/>
+            <ComboBox x:Name="OutputAudioComboBox" MinWidth="500" HorizontalAlignment="Center" Background="Black" BorderBrush="Black"/>
-            <CheckBox x:Name="LowLatencyCheckbox" Content="Low Latency Mode (Reduces audio quality)" HorizontalAlignment="Center" Margin="0,10,0,0"/>
+            <CheckBox x:Name="LowLatencyCheckbox" Content="Low Latency Mode (Reduces audio quality)" HorizontalAlignment="Center" Margin="0,10,0,0" Foreground="White"/>
             <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,20,0,5">
-                <Button x:Name="AddAudioGraphButton" Content="Add Audio Graph" HorizontalContentAlignment="Center" Background="#54FFFFFF" Click="AddAudioGraphButton_Click"/>
+                <Button x:Name="AddAudioGraphButton" Content="Add Audio Graph" HorizontalContentAlignment="Center" Background="#54FFFFFF" Click="AddAudioGraphButton_Click" Foreground="White"/>
             </StackPanel>
         </StackPanel>
         <ScrollViewer Grid.Row="1" Margin="10,5,10,5"  Padding="0,0,10,0">

Audio Router WPF/MainWindow.xaml.cs

@@ -31,12 +31,18 @@ namespace Audio_Router_WPF
         // The list of audio devices
         DeviceInformationCollection sourceDevices;
         DeviceInformationCollection targetDevices;
+
+        #pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable. (these fields cannot be assigned 
         public MainWindow()
         { 
             InitializeComponent();
+            
+        }
+        protected override void OnInitialized(EventArgs e)
+        {
+            base.OnInitialized(e);
             _ = Task.Run(() => FindAudioSources());
         }
-
         private async void AddAudioGraphButton_Click(object sender, RoutedEventArgs e)
         {
             await CreateAudioGraph();
@@ -57,6 +63,7 @@ namespace Audio_Router_WPF
             DeviceInformation defaultOutput = await DeviceInformation.CreateFromIdAsync(MediaDevice.GetDefaultAudioRenderId(AudioDeviceRole.Default));
             DeviceInformation defaultInput = await DeviceInformation.CreateFromIdAsync(MediaDevice.GetDefaultAudioCaptureId(AudioDeviceRole.Default));
 
+
             Dispatcher.Invoke(() =>
             {
                 // Set the Input device
@@ -72,16 +79,19 @@ namespace Audio_Router_WPF
                         _ = InputAudioComboBox.Items.Add(sourceDevices[i].Name);
                     }
                 }
+                // _ = InputAudioComboBox.Items.Add("--Output nodes--"); // This requires further work, implementing W
                 for (int i = 0; i < targetDevices.Count; i++)
                 {
                     if (targetDevices[i].Id == defaultOutput.Id)
                     {
                         _ = OutputAudioComboBox.Items.Add(targetDevices[i].Name + " (Default Device)");
+                        //_ = InputAudioComboBox.Items.Add(targetDevices[i].Name + " (Default Device)");
                         OutputAudioComboBox.SelectedIndex = i;
                     }
                     else
                     {
                         _ = OutputAudioComboBox.Items.Add(targetDevices[i].Name);
+                        //_ = InputAudioComboBox.Items.Add(targetDevices[i].Name);
                     }
                 }
             });
@@ -91,8 +101,21 @@ namespace Audio_Router_WPF
         private async Task CreateAudioGraph()
         {
             App.displayRequest.RequestActive();
+            bool isInputDevice = true;
+            DeviceInformation inputDevice;
+            if (InputAudioComboBox.SelectedIndex < sourceDevices.Count)
+            {
+                isInputDevice = true;
+                inputDevice = sourceDevices[InputAudioComboBox.SelectedIndex];
+            }
+            else if (InputAudioComboBox.SelectedIndex == sourceDevices.Count) return;
+            else
+            {
+                isInputDevice = false;
+                inputDevice = targetDevices[InputAudioComboBox.SelectedIndex - (sourceDevices.Count + 1)];
+            }
             DeviceInformation outputDevice = targetDevices[OutputAudioComboBox.SelectedIndex];
-            DeviceInformation inputDevice = sourceDevices[InputAudioComboBox.SelectedIndex];
+            
             AudioGraphSettings settings = LowLatencyCheckbox.IsChecked == true
                 ? new AudioGraphSettings(AudioRenderCategory.Media)
                 {
@@ -121,8 +144,9 @@ namespace Audio_Router_WPF
                 return;
             }
 
-            CreateAudioDeviceInputNodeResult deviceInputNodeResult = await ag.CreateDeviceInputNodeAsync(MediaCategory.Other, ag.EncodingProperties, inputDevice);
+            //CreateAudioDeviceInputNodeResult deviceInputNodeResult = await ag.CreateDeviceInputNodeAsync(MediaCategory.Other, ag.EncodingProperties, inputDevice);
-
+            CreateAudioDeviceInputNodeResult deviceInputNodeResult = await ag.CreateDeviceInputNodeAsync(,,);
+            AudioFrameInputNode g = ag.CreateFrameInputNode();
             if (deviceInputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
             {
                 // Fail-safe, switch to using the default encoding properties
@@ -143,9 +167,9 @@ namespace Audio_Router_WPF
                     return;
                 }
             }
-
             // Create the device output node connection
             CreateAudioDeviceOutputNodeResult deviceOutputNodeResult = await ag.CreateDeviceOutputNodeAsync();
+            //deviceOutputNodeResult.DeviceOutputNode.Creat
             if (deviceOutputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
             {
                 return;
@@ -155,7 +179,6 @@ namespace Audio_Router_WPF
             ag.Start();
             AudioGraphConnection graphConnection = new AudioGraphConnection(ag, deviceOutputNodeResult.DeviceOutputNode, deviceInputNodeResult.DeviceInputNode, Dispatcher);
             App.appRef.audioGraphConnections.Add(graphConnection);
-
             // Hold a reference to the created button; when clicked we must also ensure we remove this visual element from the grid display
             Grid renderGrid = graphConnection.GetAsDisplayItem(out Button visualButton);
             CreatedGraphs.Children.Add(renderGrid);
@@ -165,6 +188,7 @@ namespace Audio_Router_WPF
                 visualButton.Click -= handler;
                 DestroyVisualElement(ref renderGrid);
             }
+
             visualButton.Click += handler;
         }