Fixed null reference errors (#1916)

Added null checks

src/CommunityToolkit/Xamarin.CommunityToolkit/Views/CameraView/iOS/FormsCameraView.ios.cs

@@ -264,10 +264,13 @@ public void StartRecord()
  captureSession.AddOutput(videoOutput);
 
  var audioDevice = AVCaptureDevice.GetDefaultDevice(AVMediaTypes.Audio);
- var audioInput = AVCaptureDeviceInput.FromDevice(audioDevice);
+ if (audioDevice != null)
+ {
+ var audioInput = AVCaptureDeviceInput.FromDevice(audioDevice);
 
- if (captureSession.CanAddInput(audioInput))
- captureSession.AddInput(audioInput);
+ if (audioInput != null && captureSession.CanAddInput(audioInput))
+ captureSession.AddInput(audioInput);
+ }
 
  captureSession.CommitConfiguration();
 

src/CommunityToolkit/Xamarin.CommunityToolkit/Views/MediaElement/iOS/MediaElementRenderer.ios.cs

@@ -85,7 +85,7 @@ protected virtual void UpdateSource()
  }
  else
  {
- if (Element.Source is XCT.FileMediaSource fileSource)
+ if (Element.Source is XCT.FileMediaSource fileSource && fileSource.File != null)
  asset = AVAsset.FromUrl(NSUrl.FromFilename(fileSource.File));
  }
 

src/CommunityToolkit/Xamarin.CommunityToolkit/Views/Popup/iOS/PopupRenderer.ios.cs

@@ -1,6 +1,7 @@
 using System;
 using System.ComponentModel;
 using CoreGraphics;
+using Intents;
 using UIKit;
 using Xamarin.CommunityToolkit.Helpers;
 using Xamarin.CommunityToolkit.PlatformConfiguration.iOSSpecific;
@@ -180,6 +181,9 @@ void SetSize()
 
  void SetLayout()
  {
+ if (PresentationController == null || PopoverPresentationController == null)
+ return;
+
  ((UIPopoverPresentationController)PresentationController).SourceRect = new CGRect(0, 0, PreferredContentSize.Width, PreferredContentSize.Height);
 
  _ = Element ?? throw new InvalidOperationException($"{nameof(Element)} cannot be null");
@@ -199,6 +203,7 @@ void SetLayout()
  _ => 0f
  };
 
+
  PopoverPresentationController.SourceRect = new CGRect(originX, originY, 0, 0);
  PopoverPresentationController.PermittedArrowDirections = 0;
  }
@@ -241,6 +246,10 @@ void SetView()
 
  void SetPresentationController()
  {
+
+ if (PresentationController == null)
+ return;
+
  var popOverDelegate = new PopoverDelegate();
  popOverDelegate.PopoverDismissed += HandlePopoverDelegateDismissed;
 
@@ -284,8 +293,7 @@ protected override void Dispose(bool disposing)
  Element.PropertyChanged -= OnElementPropertyChanged;
  Element = null;
 
- var presentationController = (UIPopoverPresentationController)PresentationController;
- if (presentationController != null)
+ if (PresentationController is UIPopoverPresentationController presentationController)
  presentationController.Delegate = null;
  }
  }