Added ICancellationTokenProvider. Moved Abp project to latest c# language features.

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Domain/Repositories/EntityFrameworkCore/EfCoreRepository.cs

@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 using Microsoft.EntityFrameworkCore;
 using Volo.Abp.Domain.Entities;
 using Volo.Abp.EntityFrameworkCore;
+using Volo.Abp.Threading;
 
 namespace Volo.Abp.Domain.Repositories.EntityFrameworkCore
 {
@@ -45,14 +46,14 @@ namespace Volo.Abp.Domain.Repositories.EntityFrameworkCore
             return DbSet.AsQueryable();
         }
 
-        public override Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = new CancellationToken())
+        public override Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = default(CancellationToken))
         {
-            return DbSet.ToListAsync(cancellationToken);
+            return DbSet.ToListAsync(CancellationTokenProvider.FallbackToProvider(cancellationToken));
         }
 
         public override async Task<TEntity> GetAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken))
         {
-            var entity = await FindAsync(id, cancellationToken);
+            var entity = await FindAsync(id, CancellationTokenProvider.FallbackToProvider(cancellationToken));
 
             if (entity == null)
             {
@@ -69,7 +70,7 @@ namespace Volo.Abp.Domain.Repositories.EntityFrameworkCore
 
         public override Task<TEntity> FindAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken))
         {
-            return DbSet.FindAsync(new object[] { id }, cancellationToken);
+            return DbSet.FindAsync(new object[] { id }, CancellationTokenProvider.FallbackToProvider(cancellationToken));
         }
 
         public override TEntity Insert(TEntity entity, bool autoSave = false)
@@ -90,7 +91,7 @@ namespace Volo.Abp.Domain.Repositories.EntityFrameworkCore
 
             if (autoSave)
             {
-                await DbContext.SaveChangesAsync(cancellationToken);
+                await DbContext.SaveChangesAsync(CancellationTokenProvider.FallbackToProvider(cancellationToken));
             }
 
             return savedEntity;
@@ -109,7 +110,7 @@ namespace Volo.Abp.Domain.Repositories.EntityFrameworkCore
 
         public override async Task DeleteAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken = default(CancellationToken))
         {
-            var entities = await GetQueryable().Where(predicate).ToListAsync(cancellationToken);
+            var entities = await GetQueryable().Where(predicate).ToListAsync(CancellationTokenProvider.FallbackToProvider(cancellationToken));
             foreach (var entity in entities)
             {
                 DbSet.Remove(entity);
@@ -118,25 +119,25 @@ namespace Volo.Abp.Domain.Repositories.EntityFrameworkCore
 
         public override Task<long> GetCountAsync(CancellationToken cancellationToken = default(CancellationToken))
         {
-            return GetQueryable().LongCountAsync(cancellationToken);
+            return GetQueryable().LongCountAsync(CancellationTokenProvider.FallbackToProvider(cancellationToken));
         }
 
         public virtual Task EnsureCollectionLoadedAsync<TProperty>(
             TEntity entity,
             Expression<Func<TEntity, IEnumerable<TProperty>>> propertyExpression,
-            CancellationToken cancellationToken)
+            CancellationToken cancellationToken = default(CancellationToken))
             where TProperty : class
         {
-            return DbContext.Entry(entity).Collection(propertyExpression).LoadAsync(cancellationToken);
+            return DbContext.Entry(entity).Collection(propertyExpression).LoadAsync(CancellationTokenProvider.FallbackToProvider(cancellationToken));
         }
 
         public virtual Task EnsurePropertyLoadedAsync<TProperty>(
             TEntity entity,
             Expression<Func<TEntity, TProperty>> propertyExpression,
-            CancellationToken cancellationToken)
+            CancellationToken cancellationToken = default(CancellationToken))
             where TProperty : class
         {
-            return DbContext.Entry(entity).Reference(propertyExpression).LoadAsync(cancellationToken);
+            return DbContext.Entry(entity).Reference(propertyExpression).LoadAsync(CancellationTokenProvider.FallbackToProvider(cancellationToken));
         }
     }
 }

src/Volo.Abp/System/Collections/Generic/AbpDictionaryExtensions.cs

@@ -22,7 +22,7 @@ namespace System.Collections.Generic
                 return true;
             }
 
-            value = default(T);
+            value = default;
             return false;
         }
 
@@ -37,7 +37,7 @@ namespace System.Collections.Generic
         public static TValue GetOrDefault<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key)
         {
             TValue obj;
-            return dictionary.TryGetValue(key, out obj) ? obj : default(TValue);
+            return dictionary.TryGetValue(key, out obj) ? obj : default;
         }
 
         /// <summary>
@@ -51,7 +51,7 @@ namespace System.Collections.Generic
         public static TValue GetOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key)
         {
             TValue obj;
-            return dictionary.TryGetValue(key, out obj) ? obj : default(TValue);
+            return dictionary.TryGetValue(key, out obj) ? obj : default;
         }
 
         /// <summary>
@@ -65,7 +65,7 @@ namespace System.Collections.Generic
         public static TValue GetOrDefault<TKey, TValue>(this IReadOnlyDictionary<TKey, TValue> dictionary, TKey key)
         {
             TValue obj;
-            return dictionary.TryGetValue(key, out obj) ? obj : default(TValue);
+            return dictionary.TryGetValue(key, out obj) ? obj : default;
         }
 
         /// <summary>

src/Volo.Abp/System/Reflection/AbpMemberInfoExtensions.cs

@@ -28,7 +28,7 @@ namespace System.Reflection
                 return (TAttribute)attrs[0];
             }
 
-            return default(TAttribute);
+            return default;
         }
 
 

src/Volo.Abp/Volo.Abp.csproj

@@ -4,6 +4,7 @@
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
     <AssemblyName>Volo.Abp</AssemblyName>
     <PackageId>Volo.Abp</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>

src/Volo.Abp/Volo.Abp.csproj.DotSettings

@@ -0,0 +1,2 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:String x:Key="/Default/CodeInspection/CSharpLanguageProject/LanguageLevel/@EntryValue">CSharp71</s:String></wpf:ResourceDictionary>

src/Volo.Abp/Volo/Abp/AbpKernelModule.cs

@@ -5,6 +5,7 @@ using Volo.Abp.Localization;
 using Volo.Abp.Modularity;
 using Volo.Abp.ObjectMapping;
 using Volo.Abp.Reflection;
+using Volo.Abp.Threading;
 using Volo.Abp.Uow;
 using Volo.Abp.Validation;
 
@@ -40,6 +41,7 @@ namespace Volo.Abp
 
             services.AddAssemblyOf<AbpKernelModule>();
 
+            services.AddSingleton<ICancellationTokenProvider>(NullCancellationTokenProvider.Instance);
             services.AddSingleton<IRequestedApiVersion>(NullRequestedApiVersion.Instance);
             services.AddSingleton(typeof(IDataFilter<>), typeof(DataFilter<>));
             

src/Volo.Abp/Volo/Abp/Domain/Entities/Entity.cs

@@ -26,7 +26,7 @@ namespace Volo.Abp.Domain.Entities
         /// <inheritdoc/>
         public virtual bool IsTransient()
         {
-            if (EqualityComparer<TPrimaryKey>.Default.Equals(Id, default(TPrimaryKey)))
+            if (EqualityComparer<TPrimaryKey>.Default.Equals(Id, default))
             {
                 return true;
             }

src/Volo.Abp/Volo/Abp/Domain/Repositories/IQueryableRepository.cs

@@ -34,6 +34,6 @@ namespace Volo.Abp.Domain.Repositories
         /// </summary>
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <param name="predicate">A condition to filter entities</param>
-        Task DeleteAsync([NotNull] Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken = default(CancellationToken));
+        Task DeleteAsync([NotNull] Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken = default);
     }
 }

src/Volo.Abp/Volo/Abp/Domain/Repositories/IRepository.cs

@@ -33,7 +33,7 @@ namespace Volo.Abp.Domain.Repositories
         /// </summary>
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <returns>List of entities</returns>
-        Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Gets an entity with given primary key.
@@ -52,7 +52,7 @@ namespace Volo.Abp.Domain.Repositories
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <returns>Entity</returns>
         [NotNull]
-        Task<TEntity> GetAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken));
+        Task<TEntity> GetAsync(TPrimaryKey id, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Gets an entity with given primary key or null if not found.
@@ -68,7 +68,7 @@ namespace Volo.Abp.Domain.Repositories
         /// <param name="id">Primary key of the entity to get</param>
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <returns>Entity or null</returns>
-        Task<TEntity> FindAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken));
+        Task<TEntity> FindAsync(TPrimaryKey id, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Inserts a new entity.
@@ -91,7 +91,7 @@ namespace Volo.Abp.Domain.Repositories
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <param name="entity">Inserted entity</param>
         [NotNull]
-        Task<TEntity> InsertAsync([NotNull] TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default(CancellationToken));
+        Task<TEntity> InsertAsync([NotNull] TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Updates an existing entity.
@@ -106,7 +106,7 @@ namespace Volo.Abp.Domain.Repositories
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <param name="entity">Entity</param>
         [NotNull]
-        Task<TEntity> UpdateAsync([NotNull] TEntity entity, CancellationToken cancellationToken = default(CancellationToken));
+        Task<TEntity> UpdateAsync([NotNull] TEntity entity, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Deletes an entity.
@@ -119,7 +119,7 @@ namespace Volo.Abp.Domain.Repositories
         /// </summary>
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <param name="entity">Entity to be deleted</param>
-        Task DeleteAsync([NotNull] TEntity entity, CancellationToken cancellationToken = default(CancellationToken));
+        Task DeleteAsync([NotNull] TEntity entity, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Deletes an entity by primary key.
@@ -132,7 +132,7 @@ namespace Volo.Abp.Domain.Repositories
         /// </summary>
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <param name="id">Primary key of the entity</param>
-        Task DeleteAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken));
+        Task DeleteAsync(TPrimaryKey id, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Get list of all entities without any filtering.
@@ -145,6 +145,6 @@ namespace Volo.Abp.Domain.Repositories
         /// </summary>
         /// <param name="cancellationToken">A <see cref="T:System.Threading.CancellationToken" /> to observe while waiting for the task to complete.</param>
         /// <returns>List of entities</returns>
-        Task<long> GetCountAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task<long> GetCountAsync(CancellationToken cancellationToken = default);
     }
 }

src/Volo.Abp/Volo/Abp/Domain/Repositories/QueryableRepositoryBase.cs

@@ -60,7 +60,7 @@ namespace Volo.Abp.Domain.Repositories
             }
         }
 
-        public virtual Task DeleteAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task DeleteAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken = default)
         {
             Delete(predicate);
             return Task.CompletedTask;

src/Volo.Abp/Volo/Abp/Domain/Repositories/RepositoryBase.cs

@@ -4,6 +4,7 @@ using System.Linq.Expressions;
 using System.Threading;
 using System.Threading.Tasks;
 using Volo.Abp.Domain.Entities;
+using Volo.Abp.Threading;
 
 namespace Volo.Abp.Domain.Repositories
 {
@@ -16,6 +17,13 @@ namespace Volo.Abp.Domain.Repositories
     public abstract class RepositoryBase<TEntity, TPrimaryKey> : IRepository<TEntity, TPrimaryKey>
         where TEntity : class, IEntity<TPrimaryKey>
     {
+        public ICancellationTokenProvider CancellationTokenProvider { get; set; }
+
+        protected RepositoryBase()
+        {
+            CancellationTokenProvider = NullCancellationTokenProvider.Instance;
+        }
+
         public abstract List<TEntity> GetList();
 
         public virtual Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = new CancellationToken())
@@ -35,35 +43,35 @@ namespace Volo.Abp.Domain.Repositories
             return entity;
         }
 
-        public virtual Task<TEntity> GetAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task<TEntity> GetAsync(TPrimaryKey id, CancellationToken cancellationToken = default)
         {
             return Task.FromResult(Get(id));
         }
 
         public abstract TEntity Find(TPrimaryKey id);
 
-        public virtual Task<TEntity> FindAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task<TEntity> FindAsync(TPrimaryKey id, CancellationToken cancellationToken = default)
         {
             return Task.FromResult(Find(id));
         }
 
         public abstract TEntity Insert(TEntity entity, bool autoSave = false);
 
-        public virtual Task<TEntity> InsertAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task<TEntity> InsertAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default)
         {
             return Task.FromResult(Insert(entity, autoSave));
         }
 
         public abstract TEntity Update(TEntity entity);
 
-        public virtual Task<TEntity> UpdateAsync(TEntity entity, CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task<TEntity> UpdateAsync(TEntity entity, CancellationToken cancellationToken = default)
         {
             return Task.FromResult(Update(entity));
         }
 
         public abstract void Delete(TEntity entity);
 
-        public virtual Task DeleteAsync(TEntity entity, CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task DeleteAsync(TEntity entity, CancellationToken cancellationToken = default)
         {
             Delete(entity);
             return Task.CompletedTask;
@@ -80,7 +88,7 @@ namespace Volo.Abp.Domain.Repositories
             Delete(entity);
         }
 
-        public virtual Task DeleteAsync(TPrimaryKey id, CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task DeleteAsync(TPrimaryKey id, CancellationToken cancellationToken = default)
         {
             Delete(id);
             return Task.CompletedTask;
@@ -88,7 +96,7 @@ namespace Volo.Abp.Domain.Repositories
 
         public abstract long GetCount();
 
-        public virtual Task<long> GetCountAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public virtual Task<long> GetCountAsync(CancellationToken cancellationToken = default)
         {
             return Task.FromResult(GetCount());
         }

src/Volo.Abp/Volo/Abp/Domain/Repositories/RepositoryExtensions.cs

@@ -15,7 +15,7 @@ namespace Volo.Abp.Domain.Repositories
             this IRepository<TEntity, TPrimaryKey> repository,
             TEntity entity,
             Expression<Func<TEntity, IEnumerable<TProperty>>> propertyExpression,
-            CancellationToken cancellationToken = default(CancellationToken)
+            CancellationToken cancellationToken = default
         )
             where TEntity : class, IEntity<TPrimaryKey>
             where TProperty : class
@@ -42,7 +42,7 @@ namespace Volo.Abp.Domain.Repositories
             this IRepository<TEntity, TPrimaryKey> repository,
             TEntity entity,
             Expression<Func<TEntity, TProperty>> propertyExpression,
-            CancellationToken cancellationToken = default(CancellationToken)
+            CancellationToken cancellationToken = default
         )
             where TEntity : class, IEntity<TPrimaryKey>
             where TProperty : class

src/Volo.Abp/Volo/Abp/ObjectMapping/DefaultObjectMapper.cs

@@ -19,7 +19,7 @@ namespace Volo.Abp.ObjectMapping
         {
             if (source == null)
             {
-                return default(TDestination);
+                return default;
             }
 
             //Check if a specific mapper is registered
@@ -39,7 +39,7 @@ namespace Volo.Abp.ObjectMapping
         {
             if (source == null)
             {
-                return default(TDestination);
+                return default;
             }
 
             //Check if a specific mapper is registered

src/Volo.Abp/Volo/Abp/Reflection/ReflectionHelper.cs

@@ -80,7 +80,7 @@ namespace Volo.Abp.Reflection
         /// <param name="memberInfo">MemberInfo</param>
         /// <param name="defaultValue">Default value (null as default)</param>
         /// <param name="inherit">Inherit attribute from base classes</param>
-        public static TAttribute GetSingleAttributeOrDefault<TAttribute>(MemberInfo memberInfo, TAttribute defaultValue = default(TAttribute), bool inherit = true)
+        public static TAttribute GetSingleAttributeOrDefault<TAttribute>(MemberInfo memberInfo, TAttribute defaultValue = default, bool inherit = true)
             where TAttribute : Attribute
         {
             //Get attribute on the member
@@ -100,7 +100,7 @@ namespace Volo.Abp.Reflection
         /// <param name="memberInfo">MemberInfo</param>
         /// <param name="defaultValue">Default value (null as default)</param>
         /// <param name="inherit">Inherit attribute from base classes</param>
-        public static TAttribute GetSingleAttributeOfMemberOrDeclaringTypeOrDefault<TAttribute>(MemberInfo memberInfo, TAttribute defaultValue = default(TAttribute), bool inherit = true)
+        public static TAttribute GetSingleAttributeOfMemberOrDeclaringTypeOrDefault<TAttribute>(MemberInfo memberInfo, TAttribute defaultValue = default, bool inherit = true)
             where TAttribute : class
         {
             return memberInfo.GetCustomAttributes(true).OfType<TAttribute>().FirstOrDefault()

src/Volo.Abp/Volo/Abp/Session/CurrentUser.cs

@@ -46,7 +46,7 @@ namespace Volo.Abp.Session
             var value = FindClaimValue(claimType);
             if (value == null)
             {
-                return default(T);
+                return default;
             }
 
             return value.To<T>();

src/Volo.Abp/Volo/Abp/Threading/CancellationTokenProviderExtensions.cs

@@ -0,0 +1,12 @@
+using System.Threading;
+
+namespace Volo.Abp.Threading
+{
+    public static class CancellationTokenProviderExtensions
+    {
+        public static CancellationToken FallbackToProvider(this ICancellationTokenProvider provider, CancellationToken prefferedValue)
+        {
+            return prefferedValue == default ? provider.Token : prefferedValue;
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Threading/ICancellationTokenProvider.cs

@@ -0,0 +1,9 @@
+using System.Threading;
+
+namespace Volo.Abp.Threading
+{
+    public interface ICancellationTokenProvider
+    {
+        CancellationToken Token { get; }
+    }
+}

src/Volo.Abp/Volo/Abp/Threading/NullCancellationTokenProvider.cs

@@ -0,0 +1,16 @@
+using System.Threading;
+
+namespace Volo.Abp.Threading
+{
+    public class NullCancellationTokenProvider : ICancellationTokenProvider
+    {
+        public static NullCancellationTokenProvider Instance { get; } = new NullCancellationTokenProvider();
+
+        public CancellationToken Token { get; } = default;
+
+        private NullCancellationTokenProvider()
+        {
+            
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/ChildUnitOfWork.cs

@@ -56,7 +56,7 @@ namespace Volo.Abp.Uow
             _parent.SaveChanges();
         }
 
-        public Task SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public Task SaveChangesAsync(CancellationToken cancellationToken = default)
         {
             return _parent.SaveChangesAsync(cancellationToken);
         }
@@ -66,7 +66,7 @@ namespace Volo.Abp.Uow
 
         }
 
-        public Task CompleteAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public Task CompleteAsync(CancellationToken cancellationToken = default)
         {
             return Task.CompletedTask;
         }
@@ -76,7 +76,7 @@ namespace Volo.Abp.Uow
             _parent.Rollback();
         }
 
-        public Task RollbackAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public Task RollbackAsync(CancellationToken cancellationToken = default)
         {
             return _parent.RollbackAsync(cancellationToken);
         }

src/Volo.Abp/Volo/Abp/Uow/ISupportsSavingChanges.cs

@@ -7,6 +7,6 @@ namespace Volo.Abp.Uow
     {
         void SaveChanges();
 
-        Task SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task SaveChangesAsync(CancellationToken cancellationToken = default);
     }
 }

src/Volo.Abp/Volo/Abp/Uow/IUnitOfWork.cs

@@ -31,14 +31,14 @@ namespace Volo.Abp.Uow
 
         void SaveChanges();
 
-        Task SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task SaveChangesAsync(CancellationToken cancellationToken = default);
 
         void Complete();
 
-        Task CompleteAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task CompleteAsync(CancellationToken cancellationToken = default);
 
         void Rollback();
 
-        Task RollbackAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task RollbackAsync(CancellationToken cancellationToken = default);
     }
 }

src/Volo.Abp/Volo/Abp/Uow/UnitOfWork.cs

@@ -77,7 +77,7 @@ namespace Volo.Abp.Uow
             }
         }
 
-        public virtual async Task SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public virtual async Task SaveChangesAsync(CancellationToken cancellationToken = default)
         {
             foreach (var databaseApi in _databaseApis.Values)
             {
@@ -110,7 +110,7 @@ namespace Volo.Abp.Uow
             }
         }
 
-        public virtual async Task CompleteAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public virtual async Task CompleteAsync(CancellationToken cancellationToken = default)
         {
             if (_isRolledback)
             {
@@ -144,7 +144,7 @@ namespace Volo.Abp.Uow
             RollbackAll();
         }
 
-        public virtual async Task RollbackAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public virtual async Task RollbackAsync(CancellationToken cancellationToken = default)
         {
             if (_isRolledback)
             {