c# – 调用方法“Boolean Equals”提供的参数数不正确

为什么我得到一个参数异常说我把错误的参数数传递给string.equals方法？

我通过了THREE的论点,应该是正确的.实际上它应该抛出编译时错误不是运行时…

你看到错误吗？

var translations = await (from l in context.Languages
                  join t in context.Translations on l.ISO639_ISO3166 equals t.ISO639_ISO3166
                  where string.Equals(l.ApplicationName,applicationName,StringComparison.InvariantCultureIgnoreCase)
                  select new Translation
                  {
                      Key = t.Key,Text = t.Text
                  }).ToListAsync();

UPDATE

Test Name:  GetTranslations
Test FullName:  TaaS.IntegrationTests.Tests.TranslationRepositoryTests.GetTranslations
Test Source:    C:\test\TaaS-WebApplication\TaaS.IntegrationTests\Tests\TranslationRepositoryTests.cs : line 17
Test Outcome:   Failed
Test Duration:  0:00:00,0473367

Result StackTrace:  
at System.Linq.Expressions.Expression.getmethodBasedBinaryOperator(ExpressionType binaryType,Expression left,Expression right,MethodInfo method,Boolean liftToNull)
   at System.Linq.Expressions.Expression.Equal(Expression left,Boolean liftToNull,MethodInfo method)
   at System.Data.Entity.Core.Objects.ELinq.LinqExpressionnormalizer.VisitMethodCall(MethodCallExpression m)
   at System.Linq.Expressions.EntityExpressionVisitor.Visit(Expression exp)
   at System.Linq.Expressions.EntityExpressionVisitor.VisitLambda(LambdaExpression lambda)
   at System.Linq.Expressions.EntityExpressionVisitor.Visit(Expression exp)
   at System.Linq.Expressions.EntityExpressionVisitor.VisitUnary(UnaryExpression u)
   at System.Linq.Expressions.EntityExpressionVisitor.Visit(Expression exp)
   at System.Linq.Expressions.EntityExpressionVisitor.VisitExpressionList(ReadOnlyCollection`1 original)
   at System.Linq.Expressions.EntityExpressionVisitor.VisitMethodCall(MethodCallExpression m)
   at System.Data.Entity.Core.Objects.ELinq.LinqExpressionnormalizer.VisitMethodCall(MethodCallExpression m)
   at System.Linq.Expressions.EntityExpressionVisitor.Visit(Expression exp)
   at System.Linq.Expressions.EntityExpressionVisitor.VisitExpressionList(ReadOnlyCollection`1 original)
   at System.Linq.Expressions.EntityExpressionVisitor.VisitMethodCall(MethodCallExpression m)
   at System.Data.Entity.Core.Objects.ELinq.LinqExpressionnormalizer.VisitMethodCall(MethodCallExpression m)
   at System.Linq.Expressions.EntityExpressionVisitor.Visit(Expression exp)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter..ctor(Funcletizer funcletizer,Expression expression)
   at System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.CreateExpressionConverter()
   at System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__displayClassc.<GetResultsAsync>b__a()
   at System.Data.Entity.Core.Objects.ObjectContext.<ExecuteInTransactionAsync>d__3d`1.MoveNext()
--- End of stack trace from prevIoUs location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Data.Entity.sqlServer.DefaultsqlExecutionStrategy.<ExecuteAsyncImplementation>d__9`1.MoveNext()
--- End of stack trace from prevIoUs location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Data.Entity.Utilities.TaskExtensions.CultureAwaiter`1.GetResult()
   at System.Data.Entity.Core.Objects.ObjectQuery`1.<GetResultsAsync>d__e.MoveNext()
--- End of stack trace from prevIoUs location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Data.Entity.Utilities.TaskExtensions.CultureAwaiter`1.GetResult()
   at System.Data.Entity.Internal.LazyAsyncEnumerator`1.<FirstMoveNextAsync>d__0.MoveNext()
--- End of stack trace from prevIoUs location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Data.Entity.Infrastructure.IDbAsyncEnumerableExtensions.<ForEachAsync>d__5`1.MoveNext()
--- End of stack trace from prevIoUs location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at TaaS.Repository.TranslationRepository.<GetTranslationsAsync>d__2.MoveNext() in C:\_REPOSITORIES\taas-application\TaaS-WebApplication\TaaS.Repository\TranslationRepository.cs:line 20
--- End of stack trace from prevIoUs location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at TaaS.IntegrationTests.Tests.TranslationRepositoryTests.GetTranslations() in C:\_REPOSITORIES\taas-application\TaaS-WebApplication\TaaS.IntegrationTests\Tests\TranslationRepositoryTests.cs:line 45
Result Message: 
Test method TaaS.IntegrationTests.Tests.TranslationRepositoryTests.GetTranslations threw exception: 
System.ArgumentException: Incorrect number of arguments supplied for call to method 'Boolean Equals(System.String,System.String,System.StringComparison)'

解决方法

这是一个运行时错误,因为您可能会针对 Linq query provider运行,该版本需要从您的C#代码创建的C#编译器为 expression,并在运行时执行.提供商可能无法翻译此等量的重载.

尝试将您的Linq查询更改为：

(from l in context.Languages
join t in context.Translations on l.ISO639_ISO3166 equals t.ISO639_ISO3166).AsEnumerable()
.Where(l => string.Equals(l.ApplicationName,StringComparison.InvariantCultureIgnoreCase))
.Select(new Translation
              {
                  Key = t.Key,Text = t.Text
              }).ToListAsync();