Enable Nullability for Android, GTK, iOS, Tizen, UWP & WPF Sample Projects (#1015)

* Enable Nullable on Unit Tests

* Enable Nullable on Xamarin.CommunityToolkit.Markup

* Enable Nullable on Xamarin.CommunityToolkit.Sample

* Enable Nullable on Android, GTK, iOS and Tizen Samples

* Enable Nullable for UWP & WPF Sample Projects

Author: TheCodeTraveler

samples/XCT.Sample.Android/SplashActivity.cs

@@ -9,7 +9,7 @@ namespace Xamarin.CommunityToolkit.Sample.Droid
 	[Activity(Label = "XamarinCommunityToolkitSample", Icon = "@mipmap/icon", Theme = "@style/SplashTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
 	public class SplashActivity : AppCompatActivity
 	{
-		protected override void OnCreate(Bundle savedInstanceState)
+		protected override void OnCreate(Bundle? savedInstanceState)
 		{
 			base.OnCreate(savedInstanceState);
 			var intent = new Intent(this, typeof(MainActivity));

samples/XCT.Sample.Android/Xamarin.CommunityToolkit.Sample.Android.csproj

@@ -22,6 +22,9 @@
     <AndroidHttpClientHandlerType>Xamarin.Android.Net.AndroidClientHandler</AndroidHttpClientHandlerType>
     <NuGetPackageImportStamp>
     </NuGetPackageImportStamp>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>

samples/XCT.Sample.GTK/Xamarin.CommunityToolkit.Sample.GTK.csproj

@@ -13,6 +13,9 @@
     <FileAlignment>512</FileAlignment>
     <Deterministic>true</Deterministic>
     <TargetFrameworkProfile />
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>

samples/XCT.Sample.Tizen/Xamarin.CommunityToolkit.Sample.Tizen.csproj

@@ -3,6 +3,9 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>tizen40</TargetFramework>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>

samples/XCT.Sample.UWP/Xamarin.CommunityToolkit.Sample.UWP.csproj

@@ -18,6 +18,9 @@
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{A5A43C5B-DE2A-4C0C-9213-0A381AF9435A};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <AppxPackageSigningEnabled>false</AppxPackageSigningEnabled>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|ARM'">
     <DebugSymbols>true</DebugSymbols>

samples/XCT.Sample.WPF/Xamarin.CommunityToolkit.Sample.WPF.csproj

@@ -16,6 +16,9 @@
     <Deterministic>true</Deterministic>
     <NuGetPackageImportStamp>
     </NuGetPackageImportStamp>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>

samples/XCT.Sample.iOS/Renderers/NoLineNavigationRenderer.cs

@@ -25,8 +25,11 @@ public override void ViewWillAppear(bool animated)
 			// Newest iOS version fix - trycatch isn't optimal
 			try
 			{
-				NavigationBar.ScrollEdgeAppearance.ShadowImage = new UIKit.UIImage();
-				NavigationBar.ScrollEdgeAppearance.ShadowColor = null;
+				if (NavigationBar.ScrollEdgeAppearance != null)
+				{
+					NavigationBar.ScrollEdgeAppearance.ShadowImage = new UIKit.UIImage();
+					NavigationBar.ScrollEdgeAppearance.ShadowColor = null;
+				}
 			}
 			catch (Exception)
 			{

samples/XCT.Sample.iOS/Xamarin.CommunityToolkit.Sample.iOS.csproj

@@ -15,6 +15,9 @@
     <MtouchEnableSGenConc>true</MtouchEnableSGenConc>
     <MtouchHttpClientHandler>NSUrlSessionHandler</MtouchHttpClientHandler>
     <ProvisioningType>automatic</ProvisioningType>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhoneSimulator' ">
     <DebugSymbols>true</DebugSymbols>