Improved sample code.

Author: kekyo

samples/FlashCap.Avalonia/FlashCap.Avalonia.UI/ViewModels/MainWindowViewModel.cs

@@ -9,7 +9,6 @@
 
 using Avalonia.Controls;
 using Epoxy;
-using FlashCap.Devices;
 using SkiaSharp;
 using System;
 using System.Collections.ObjectModel;
@@ -188,8 +187,10 @@ private ValueTask OnDeviceChangedAsync(CaptureDeviceDescriptor? descriptor)
 
             this.Characteristics = this.CharacteristicsList.FirstOrDefault();
 #endif
-
-            this.UpdateCurrentState(States.Ready);
+            if (this.Characteristics != null)
+            {
+                this.UpdateCurrentState(States.Ready);
+            }
         }
         else
         {

samples/FlashCap.Avalonia/FlashCap.Avalonia.UI/Views/MainWindow.axaml

@@ -37,13 +37,16 @@
                           SelectedItem="{Binding Characteristics, Mode=TwoWay}" />
             </StackPanel>
             <StackPanel Orientation="Horizontal">
-                <Button IsEnabled="{Binding IsEnabledStartCapture}"
+                <Button BorderBrush="White" BorderThickness="1"
+                        IsEnabled="{Binding IsEnabledStartCapture}"
                         Content="Start capture"
                         Command="{Binding StartCapture}" />
-                <Button IsEnabled="{Binding IsEnabledStopCapture}"
+                <Button BorderBrush="White" BorderThickness="1"
+                        IsEnabled="{Binding IsEnabledStopCapture}"
                         Content="Stop capture"
                         Command="{Binding StopCapture}" />
-                <Button IsEnabled="{Binding IsEnabledShowPropertyPage}"
+                <Button BorderBrush="White" BorderThickness="1"
+                        IsEnabled="{Binding IsEnabledShowPropertyPage}"
                         Content="Show property page"
                         Command="{Binding ShowPropertyPage}" />
             </StackPanel>

samples/FlashCap.Wpf/ViewModels/MainWindowViewModel.cs

@@ -8,7 +8,6 @@
 ////////////////////////////////////////////////////////////////////////////
 
 using Epoxy;
-using FlashCap.Devices;
 using SkiaSharp;
 using System;
 using System.Collections.ObjectModel;
@@ -180,8 +179,10 @@ private ValueTask OnDeviceChangedAsync(CaptureDeviceDescriptor? descriptor)
 
             this.Characteristics = this.CharacteristicsList.FirstOrDefault();
 #endif
-
-            this.UpdateCurrentState(States.Ready);
+            if (this.Characteristics != null)
+            {
+                this.UpdateCurrentState(States.Ready);
+            }
         }
         else
         {