Enhances Nullable Reference Type support

Directory.Build.props

@@ -156,13 +156,13 @@
 
   <!-- Versions: Directory.Packages.props (Central Package Management). PrivateAssets=all is implicit. -->
   <ItemGroup>
-    <GlobalPackageReference Include="Microsoft.NETFramework.ReferenceAssemblies"
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies"
                             Condition=" $(UseMaui) != 'true' " />
-    <GlobalPackageReference Include="Nerdbank.GitVersioning"
+    <PackageReference Include="Nerdbank.GitVersioning"
                             Condition=" $(DISABLE_GITVERSIONING) != 'true' AND !$(MSBuildProjectDirectory.Contains('e2e')) " />
-    <GlobalPackageReference Include="Microsoft.SourceLink.GitHub"
+    <PackageReference Include="Microsoft.SourceLink.GitHub"
                             Condition=" $(IsPackable) " />
-    <GlobalPackageReference Include="Microsoft.Sbom.Targets"
+    <PackageReference Include="Microsoft.Sbom.Targets"
                             Condition=" $(IsPackable) " />
   </ItemGroup>
 

src/Prism.Core/Common/IParameters.cs

@@ -6,14 +6,14 @@ namespace Prism.Common
     /// <summary>
     /// Defines a contract for specifying values associated with a unique key.
     /// </summary>
-    public interface IParameters : IEnumerable<KeyValuePair<string, object>>
+    public interface IParameters : IEnumerable<KeyValuePair<string, object?>>
     {
         /// <summary>
         /// Adds the specified key and value to the parameter collection.
         /// </summary>
         /// <param name="key">The key of the parameter to add.</param>
         /// <param name="value">The value of the parameter to add.</param>
-        void Add(string key, object value);
+        void Add(string key, object? value);
 
         /// <summary>
         /// Determines whether the <see cref="IParameters"/> contains the specified <paramref name="key"/>.

src/Prism.Core/Common/ParametersBase.cs

@@ -104,7 +104,7 @@ public object? this[string key]
         /// </summary>
         /// <param name="key">The key to reference this value in the parameters collection.</param>
         /// <param name="value">The value of the parameter to store.</param>
-        public void Add(string key, object value) =>
+        public void Add(string key, object? value) =>
             _entries.Add(new KeyValuePair<string, object?>(key, value));
 
         /// <summary>
@@ -129,7 +129,7 @@ public bool ContainsKey(string key) =>
         /// <param name="key">The key for the value to be returned.</param>
         /// <returns>Returns a matching parameter of <typeparamref name="T"/> if one exists in the Collection.</returns>
         public T GetValue<T>(string key) =>
-            _entries.GetValue<T>(key);
+            _entries.GetValue<T>(key)!;
 
         /// <summary>
         /// Returns an IEnumerable of all parameters.

src/Prism.Core/Common/ParametersExtensions.cs

@@ -21,8 +21,13 @@ public static class ParametersExtensions
         /// <param name="key">The key of the parameter to find</param>
         /// <returns>A matching value of <typeparamref name="T"/> if it exists</returns>
         [EditorBrowsable(EditorBrowsableState.Never)]
-        public static T GetValue<T>(this IEnumerable<KeyValuePair<string, object>> parameters, string key) =>
-            (T)GetValue(parameters, key, typeof(T));
+        public static T GetValue<T>(this IEnumerable<KeyValuePair<string, object?>> parameters, string key)
+        {
+            object? value = GetValue(parameters, key, typeof(T));
+            if (value is null)
+                return default!;
+            return (T)value;
+        }
 
         /// <summary>
         /// Searches <paramref name="parameters"/> for value referenced by <paramref name="key"/>
@@ -33,7 +38,7 @@ public static T GetValue<T>(this IEnumerable<KeyValuePair<string, object>> param
         /// <returns>A matching value of <paramref name="type"/> if it exists</returns>
         /// <exception cref="InvalidCastException">Unable to convert the value of Type</exception>
         [EditorBrowsable(EditorBrowsableState.Never)]
-        public static object GetValue(this IEnumerable<KeyValuePair<string, object>> parameters, string key, Type type)
+        public static object? GetValue(this IEnumerable<KeyValuePair<string, object?>> parameters, string key, Type type)
         {
             foreach (var kvp in parameters)
             {
@@ -42,7 +47,7 @@ public static object GetValue(this IEnumerable<KeyValuePair<string, object>> par
                     if (TryGetValueInternal(kvp, type, out var value))
                         return value;
 
-                    throw new InvalidCastException($"Unable to convert the value of Type '{kvp.Value.GetType().FullName}' to '{type.FullName}' for the key '{key}' ");
+                    throw new InvalidCastException($"Unable to convert the value of Type '{kvp.Value!.GetType().FullName}' to '{type.FullName}' for the key '{key}' ");
                 }
             }
 
@@ -58,7 +63,7 @@ public static object GetValue(this IEnumerable<KeyValuePair<string, object>> par
         /// <param name="value">The value of parameter to return</param>
         /// <returns>Success if value is found; otherwise returns <c>false</c></returns>
         [EditorBrowsable(EditorBrowsableState.Never)]
-        public static bool TryGetValue<T>(this IEnumerable<KeyValuePair<string, object>> parameters, string key, out T value)
+        public static bool TryGetValue<T>(this IEnumerable<KeyValuePair<string, object?>> parameters, string key, [MaybeNullWhen(false)] out T value)
         {
             var type = typeof(T);
 
@@ -75,7 +80,7 @@ public static bool TryGetValue<T>(this IEnumerable<KeyValuePair<string, object>>
                 }
             }
 
-            value = default;
+            value = default!;
             return false;
         }
 
@@ -87,7 +92,7 @@ public static bool TryGetValue<T>(this IEnumerable<KeyValuePair<string, object>>
         /// <param name="key">The key of the parameter to find</param>
         /// <returns>An IEnumerable{T} of all the values referenced by key</returns>
         [EditorBrowsable(EditorBrowsableState.Never)]
-        public static IEnumerable<T> GetValues<T>(this IEnumerable<KeyValuePair<string, object>> parameters, string key)
+        public static IEnumerable<T> GetValues<T>(this IEnumerable<KeyValuePair<string, object?>> parameters, string key)
         {
             List<T> values = [];
             var type = typeof(T);
@@ -105,7 +110,7 @@ public static IEnumerable<T> GetValues<T>(this IEnumerable<KeyValuePair<string,
             return values.ToArray();
         }
 
-        private static bool TryGetValueInternal(KeyValuePair<string, object> kvp, Type type, out object value)
+        private static bool TryGetValueInternal(KeyValuePair<string, object?> kvp, Type type, out object? value)
         {
             value = GetDefault(type);
             var valueAsString = kvp.Value is string str ? str : kvp.Value?.ToString();
@@ -141,7 +146,7 @@ private static bool TryGetValueInternal(KeyValuePair<string, object> kvp, Type t
             if (!success && type.GetInterface("System.IConvertible") != null)
             {
                 success = true;
-                value = Convert.ChangeType(kvp.Value, type);
+                value = Convert.ChangeType(kvp.Value, type)!;
             }
 
             return success;
@@ -154,7 +159,7 @@ private static bool TryGetValueInternal(KeyValuePair<string, object> kvp, Type t
         /// <param name="key">The key to search the <paramref name="parameters"/> for existence</param>
         /// <returns><c>true</c> if key exists; <c>false</c> otherwise</returns>
         [EditorBrowsable(EditorBrowsableState.Never)]
-        public static bool ContainsKey(this IEnumerable<KeyValuePair<string, object>> parameters, string key) =>
+        public static bool ContainsKey(this IEnumerable<KeyValuePair<string, object?>> parameters, string key) =>
             parameters.Any(x => string.Compare(x.Key, key, StringComparison.Ordinal) == 0);
 
         private static object? GetDefault(Type type) => type.IsValueType ? Activator.CreateInstance(type) : null;

src/Prism.Core/Common/UriParsingHelper.cs

@@ -74,7 +74,7 @@ public static INavigationParameters GetSegmentParameters(string uriSegment, INav
 
             if (parameters is not null)
             {
-                foreach (KeyValuePair<string, object> navigationParameter in parameters)
+                foreach (KeyValuePair<string, object?> navigationParameter in parameters)
                 {
                     navParameters.Add(navigationParameter.Key, navigationParameter.Value);
                 }
@@ -116,7 +116,7 @@ public static IDialogParameters GetSegmentParameters(string uriSegment, IDialogP
 
             if (parameters != null)
             {
-                foreach (KeyValuePair<string, object> navigationParameter in parameters)
+                foreach (KeyValuePair<string, object?> navigationParameter in parameters)
                 {
                     dialogParameters.Add(navigationParameter.Key, navigationParameter.Value);
                 }

src/Prism.Core/Modularity/CyclicDependencyFoundException.Desktop.cs

@@ -1,4 +1,4 @@
-
+#if NETFRAMEWORK
 
 using System;
 using System.Runtime.Serialization;
@@ -17,3 +17,5 @@ public partial class CyclicDependencyFoundException
         protected CyclicDependencyFoundException(SerializationInfo info, StreamingContext context) : base(info, context) { }
     }
 }
+
+#endif

src/Prism.Core/Modularity/DuplicateModuleException.Desktop.cs

@@ -1,4 +1,4 @@
-
+#if NETFRAMEWORK
 
 using System;
 using System.Runtime.Serialization;
@@ -17,3 +17,5 @@ public partial class DuplicateModuleException
         protected DuplicateModuleException(SerializationInfo info, StreamingContext context) : base(info, context) { }
     }
 }
+
+#endif

src/Prism.Core/Modularity/ModularityException.Desktop.cs

@@ -1,4 +1,4 @@
-
+#if NETFRAMEWORK
 
 using System;
 using System.Runtime.Serialization;
@@ -25,13 +25,13 @@ protected ModularityException(SerializationInfo info, StreamingContext context)
         /// </summary>
         /// <param name="info">The <see cref="System.Runtime.Serialization.SerializationInfo"/> that holds the serialized object data about the exception being thrown.</param>
         /// <param name="context">The <see cref="System.Runtime.Serialization.StreamingContext"/> that contains contextual information about the source or destination.</param>
-#if !NET6_0_OR_GREATER
         [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.SerializationFormatter)]
-#endif
         public override void GetObjectData(SerializationInfo info, StreamingContext context)
         {
             base.GetObjectData(info, context);
             info.AddValue("ModuleName", this.ModuleName);
         }
     }
 }
+
+#endif

src/Prism.Core/Modularity/ModuleInitializeException.Desktop.cs

@@ -1,4 +1,4 @@
-
+#if NETFRAMEWORK
 
 using System;
 using System.Runtime.Serialization;
@@ -19,3 +19,5 @@ protected ModuleInitializeException(SerializationInfo info, StreamingContext con
         }
     }
 }
+
+#endif

src/Prism.Core/Modularity/ModuleNotFoundException.Desktop.cs

@@ -1,4 +1,4 @@
-
+#if NETFRAMEWORK
 
 using System;
 using System.Runtime.Serialization;
@@ -22,3 +22,5 @@ protected ModuleNotFoundException(SerializationInfo info, StreamingContext conte
         }
     }
 }
+
+#endif

src/Prism.Core/Modularity/ModuleTypeLoadingException.Desktop.cs

@@ -1,4 +1,4 @@
-
+#if NETFRAMEWORK
 
 using System;
 using System.Runtime.Serialization;
@@ -19,3 +19,5 @@ protected ModuleTypeLoadingException(SerializationInfo info, StreamingContext co
         }
     }
 }
+
+#endif

src/Prism.Core/Mvvm/ErrorsContainer.cs

@@ -9,7 +9,7 @@ namespace Prism.Mvvm
     /// <typeparam name="T">The type of the error object.</typeparam>
     public class ErrorsContainer<T>
     {
-        private static readonly T[] noErrors = new T[0];
+        private static readonly T[] noErrors = [];
 
         /// <summary>
         /// Delegate to be called when raiseErrorsChanged is invoked.
@@ -27,25 +27,23 @@ public class ErrorsContainer<T>
         /// <param name="raiseErrorsChanged">The action that is invoked when errors are added for an object.</param>
         public ErrorsContainer(Action<string> raiseErrorsChanged)
         {
+#if NETFRAMEWORK
             if (raiseErrorsChanged == null)
             {
                 throw new ArgumentNullException(nameof(raiseErrorsChanged));
             }
+#else
+            ArgumentNullException.ThrowIfNull(raiseErrorsChanged);
+#endif
 
             this.raiseErrorsChanged = raiseErrorsChanged;
-            this.validationResults = new Dictionary<string, List<T>>();
+            validationResults = [];
         }
 
         /// <summary>
         /// Gets a value indicating whether the object has validation errors. 
         /// </summary>
-        public bool HasErrors
-        {
-            get
-            {
-                return this.validationResults.Count != 0;
-            }
-        }
+        public bool HasErrors => validationResults.Count != 0;
 
         /// <summary>
         /// Returns all the errors in the container.
@@ -61,7 +59,7 @@ public bool HasErrors
         public IEnumerable<T> GetErrors(string? propertyName)
         {
             var localPropertyName = propertyName ?? string.Empty;
-            if (this.validationResults.TryGetValue(localPropertyName, out var currentValidationResults))
+            if (validationResults.TryGetValue(localPropertyName, out var currentValidationResults))
             {
                 return currentValidationResults;
             }
@@ -76,7 +74,7 @@ public IEnumerable<T> GetErrors(string? propertyName)
         /// </summary>
         public void ClearErrors()
         {
-            foreach (var key in this.validationResults.Keys.ToArray())
+            foreach (var key in validationResults.Keys.ToArray())
             {
                 ClearErrors(key);
             }
@@ -94,7 +92,7 @@ public void ClearErrors()
         public void ClearErrors<TProperty>(Expression<Func<TProperty>> propertyExpression)
         {
             var propertyName = PropertySupport.ExtractPropertyName(propertyExpression);
-            this.ClearErrors(propertyName);
+            ClearErrors(propertyName);
         }
 
         /// <summary>
@@ -104,7 +102,7 @@ public void ClearErrors<TProperty>(Expression<Func<TProperty>> propertyExpressio
         /// <example>
         /// container.ClearErrors("SomeProperty");
         /// </example>
-        public void ClearErrors(string? propertyName) => this.SetErrors(propertyName, new List<T>());
+        public void ClearErrors(string? propertyName) => SetErrors(propertyName, new List<T>());
 
         /// <summary>
         /// Sets the validation errors for the specified property.
@@ -116,7 +114,7 @@ public void ClearErrors<TProperty>(Expression<Func<TProperty>> propertyExpressio
         public void SetErrors<TProperty>(Expression<Func<TProperty>> propertyExpression, IEnumerable<T>? propertyErrors)
         {
             var propertyName = PropertySupport.ExtractPropertyName(propertyExpression);
-            this.SetErrors(propertyName, propertyErrors);
+            SetErrors(propertyName, propertyErrors);
         }
 
         /// <summary>
@@ -130,20 +128,20 @@ public void SetErrors<TProperty>(Expression<Func<TProperty>> propertyExpression,
         public void SetErrors(string? propertyName, IEnumerable<T>? newValidationResults)
         {
             var localPropertyName = propertyName ?? string.Empty;
-            var hasCurrentValidationResults = this.validationResults.ContainsKey(localPropertyName);
+            var hasCurrentValidationResults = validationResults.ContainsKey(localPropertyName);
             var hasNewValidationResults = newValidationResults != null && newValidationResults.Count() > 0;
 
             if (hasCurrentValidationResults || hasNewValidationResults)
             {
                 if (hasNewValidationResults)
                 {
-                    this.validationResults[localPropertyName] = new List<T>(newValidationResults);
-                    this.raiseErrorsChanged(localPropertyName);
+                    validationResults[localPropertyName] = new List<T>(newValidationResults!);
+                    raiseErrorsChanged(localPropertyName);
                 }
                 else
                 {
-                    this.validationResults.Remove(localPropertyName);
-                    this.raiseErrorsChanged(localPropertyName);
+                    validationResults.Remove(localPropertyName);
+                    raiseErrorsChanged(localPropertyName);
                 }
             }
         }

src/Prism.Core/Mvvm/PropertySupport.cs

@@ -54,7 +54,7 @@ public static class PropertySupport
                 throw new ArgumentException(Resources.PropertySupport_ExpressionNotProperty_Exception, nameof(expression));
 
             var getMethod = property.GetMethod;
-            if (getMethod.IsStatic)
+            if (getMethod is null || getMethod.IsStatic)
                 throw new ArgumentException(Resources.PropertySupport_StaticExpression_Exception, nameof(expression));
 
             return memberExpression.Member.Name;

src/Prism.Core/Mvvm/ViewModelLocationProvider.cs

@@ -26,7 +26,7 @@ public static void Reset()
         {
             _factories = new Dictionary<string, Func<object>>();
             _typeFactories = new Dictionary<string, Type>();
-            _defaultViewModelFactory = type => Activator.CreateInstance(type);
+            _defaultViewModelFactory = type => Activator.CreateInstance(type)!;
             _defaultViewModelFactoryWithViewParameter = null;
             _defaultViewTypeToViewModelTypeResolver = DefaultViewTypeToViewModel;
         }
@@ -44,7 +44,7 @@ public static void Reset()
         /// <summary>
         /// The default view model factory which provides the ViewModel type as a parameter.
         /// </summary>
-        static Func<Type, object> _defaultViewModelFactory = type => Activator.CreateInstance(type);
+        static Func<Type, object> _defaultViewModelFactory = type => Activator.CreateInstance(type)!;
 
         /// <summary>
         /// ViewModelFactory that provides the View instance and ViewModel type as parameters.

src/Prism.Core/Mvvm/ViewRegistryBase{TBaseView}.cs

@@ -129,7 +129,8 @@ private IEnumerable<Type> GetCandidates(Type viewModelType)
 
             return candidates
                 .Select(x => Type.GetType(x, false))
-                .Where(x => x is not null);
+                .Where(x => x is not null)
+                .Cast<Type>();
         }
 
         return [];