Hoy estaba jugando con Entity Framework y he leído que el IL generado para C# fue diferente de VB.NET para el siguiente código:diferencias IL generado para VB.NET y C#
VB.NET:
Dim ctx As New TravelEntities
Sub Main()
CallContext()
CallContext()
CallContext()
End Sub
Private Sub CallContext()
Dim someCustomer = From x In ctx.Customer
Where x.CustomerId.Equals(5)
Select x
Console.WriteLine(someCustomer.Count())
End Sub
C#:
private static TravelEntities ctx = new TravelEntities();
static void Main(string[] args)
{
CallContext();
CallContext();
CallContext();
}
private static void CallContext()
{
var someCustomer = from x in ctx.Customer
where x.CustomerId.Equals(5)
select x;
Console.WriteLine(someCustomer.Count());
}
producen la IL siguiente:
VB:
.method private static void CallContext() cil managed
{
// Code size 195 (0xc3)
.maxstack 7
.locals init ([0] class [System.Core]System.Linq.IQueryable`1<class VB_IL_Difference.Customer> someCustomer,
[1] class [System.Core]System.Linq.Expressions.ParameterExpression VB$t_ref$S0,
[2] class [System.Core]System.Linq.Expressions.Expression[] VB$t_array$S0,
[3] class [System.Core]System.Linq.Expressions.ParameterExpression[] VB$t_array$S1,
[4] class [System.Core]System.Linq.Expressions.ParameterExpression VB$t_ref$S1,
[5] class [System.Core]System.Linq.Expressions.ParameterExpression[] VB$t_array$S2)
IL_0000: nop
IL_0001: ldsfld class VB_IL_Difference.TravelEntities VB_IL_Difference.Module1::ctx
IL_0006: callvirt instance class [System.Data.Entity]System.Data.Objects.ObjectSet`1<class VB_IL_Difference.Customer> VB_IL_Difference.TravelEntities::get_Customer()
IL_000b: ldtoken VB_IL_Difference.Customer
IL_0010: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)
IL_0015: ldstr "x"
IL_001a: call class [System.Core]System.Linq.Expressions.ParameterExpression [System.Core]System.Linq.Expressions.Expression::Parameter(class [mscorlib]System.Type,
string)
IL_001f: stloc.1
IL_0020: ldloc.1
IL_0021: ldtoken method instance int32 VB_IL_Difference.Customer::get_CustomerId()
IL_0026: call class [mscorlib]System.Reflection.MethodBase [mscorlib]System.Reflection.MethodBase::GetMethodFromHandle(valuetype [mscorlib]System.RuntimeMethodHandle)
IL_002b: castclass [mscorlib]System.Reflection.MethodInfo
IL_0030: call class [System.Core]System.Linq.Expressions.MemberExpression [System.Core]System.Linq.Expressions.Expression::Property(class [System.Core]System.Linq.Expressions.Expression,
class [mscorlib]System.Reflection.MethodInfo)
IL_0035: ldtoken method instance bool [mscorlib]System.Int32::Equals(int32)
IL_003a: call class [mscorlib]System.Reflection.MethodBase [mscorlib]System.Reflection.MethodBase::GetMethodFromHandle(valuetype [mscorlib]System.RuntimeMethodHandle)
IL_003f: castclass [mscorlib]System.Reflection.MethodInfo
IL_0044: ldc.i4.1
IL_0045: newarr [System.Core]System.Linq.Expressions.Expression
IL_004a: stloc.2
IL_004b: ldloc.2
IL_004c: ldc.i4.0
IL_004d: ldc.i4.5
IL_004e: box [mscorlib]System.Int32
IL_0053: ldtoken [mscorlib]System.Int32
IL_0058: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)
IL_005d: call class [System.Core]System.Linq.Expressions.ConstantExpression [System.Core]System.Linq.Expressions.Expression::Constant(object,
class [mscorlib]System.Type)
IL_0062: stelem.ref
IL_0063: nop
IL_0064: ldloc.2
IL_0065: call class [System.Core]System.Linq.Expressions.MethodCallExpression [System.Core]System.Linq.Expressions.Expression::Call(class [System.Core]System.Linq.Expressions.Expression,
class [mscorlib]System.Reflection.MethodInfo,
class [System.Core]System.Linq.Expressions.Expression[])
IL_006a: ldc.i4.1
IL_006b: newarr [System.Core]System.Linq.Expressions.ParameterExpression
IL_0070: stloc.3
IL_0071: ldloc.3
IL_0072: ldc.i4.0
IL_0073: ldloc.1
IL_0074: stelem.ref
IL_0075: nop
IL_0076: ldloc.3
IL_0077: call class [System.Core]System.Linq.Expressions.Expression`1<!!0> [System.Core]System.Linq.Expressions.Expression::Lambda<class [mscorlib]System.Func`2<class VB_IL_Difference.Customer,bool>>(class [System.Core]System.Linq.Expressions.Expression,
class [System.Core]System.Linq.Expressions.ParameterExpression[])
IL_007c: call class [System.Core]System.Linq.IQueryable`1<!!0> [System.Core]System.Linq.Queryable::Where<class VB_IL_Difference.Customer>(class [System.Core]System.Linq.IQueryable`1<!!0>,
class [System.Core]System.Linq.Expressions.Expression`1<class [mscorlib]System.Func`2<!!0,bool>>)
IL_0081: ldtoken VB_IL_Difference.Customer
IL_0086: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)
IL_008b: ldstr "x"
IL_0090: call class [System.Core]System.Linq.Expressions.ParameterExpression [System.Core]System.Linq.Expressions.Expression::Parameter(class [mscorlib]System.Type,
string)
IL_0095: stloc.s VB$t_ref$S1
IL_0097: ldloc.s VB$t_ref$S1
IL_0099: ldc.i4.1
IL_009a: newarr [System.Core]System.Linq.Expressions.ParameterExpression
IL_009f: stloc.s VB$t_array$S2
IL_00a1: ldloc.s VB$t_array$S2
IL_00a3: ldc.i4.0
IL_00a4: ldloc.s VB$t_ref$S1
IL_00a6: stelem.ref
IL_00a7: nop
IL_00a8: ldloc.s VB$t_array$S2
IL_00aa: call class [System.Core]System.Linq.Expressions.Expression`1<!!0> [System.Core]System.Linq.Expressions.Expression::Lambda<class [mscorlib]System.Func`2<class VB_IL_Difference.Customer,class VB_IL_Difference.Customer>>(class [System.Core]System.Linq.Expressions.Expression,
class [System.Core]System.Linq.Expressions.ParameterExpression[])
IL_00af: call class [System.Core]System.Linq.IQueryable`1<!!1> [System.Core]System.Linq.Queryable::Select<class VB_IL_Difference.Customer,class VB_IL_Difference.Customer>(class [System.Core]System.Linq.IQueryable`1<!!0>,
class [System.Core]System.Linq.Expressions.Expression`1<class [mscorlib]System.Func`2<!!0,!!1>>)
IL_00b4: stloc.0
IL_00b5: ldloc.0
IL_00b6: call int32 [System.Core]System.Linq.Queryable::Count<class VB_IL_Difference.Customer>(class [System.Core]System.Linq.IQueryable`1<!!0>)
IL_00bb: call void [mscorlib]System.Console::WriteLine(int32)
IL_00c0: nop
IL_00c1: nop
IL_00c2: ret
} // end of method Module1::CallContext
C#:
.method private hidebysig static void CallContext() cil managed
{
// Code size 141 (0x8d)
.maxstack 7
.locals init ([0] class [System.Core]System.Linq.IQueryable`1<class C_IL_Difference.Customer> someCustomer,
[1] class [System.Core]System.Linq.Expressions.ParameterExpression CS$0$0000,
[2] class [System.Core]System.Linq.Expressions.Expression[] CS$0$0001,
[3] class [System.Core]System.Linq.Expressions.ParameterExpression[] CS$0$0002)
IL_0000: nop
IL_0001: ldsfld class C_IL_Difference.TravelEntities C_IL_Difference.Program::ctx
IL_0006: callvirt instance class [System.Data.Entity]System.Data.Objects.ObjectSet`1<class C_IL_Difference.Customer> C_IL_Difference.TravelEntities::get_Customer()
IL_000b: ldtoken C_IL_Difference.Customer
IL_0010: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)
IL_0015: ldstr "x"
IL_001a: call class [System.Core]System.Linq.Expressions.ParameterExpression [System.Core]System.Linq.Expressions.Expression::Parameter(class [mscorlib]System.Type,
string)
IL_001f: stloc.1
IL_0020: ldloc.1
IL_0021: ldtoken method instance int32 C_IL_Difference.Customer::get_CustomerId()
IL_0026: call class [mscorlib]System.Reflection.MethodBase [mscorlib]System.Reflection.MethodBase::GetMethodFromHandle(valuetype [mscorlib]System.RuntimeMethodHandle)
IL_002b: castclass [mscorlib]System.Reflection.MethodInfo
IL_0030: call class [System.Core]System.Linq.Expressions.MemberExpression [System.Core]System.Linq.Expressions.Expression::Property(class [System.Core]System.Linq.Expressions.Expression,
class [mscorlib]System.Reflection.MethodInfo)
IL_0035: ldtoken method instance bool [mscorlib]System.Int32::Equals(int32)
IL_003a: call class [mscorlib]System.Reflection.MethodBase [mscorlib]System.Reflection.MethodBase::GetMethodFromHandle(valuetype [mscorlib]System.RuntimeMethodHandle)
IL_003f: castclass [mscorlib]System.Reflection.MethodInfo
IL_0044: ldc.i4.1
IL_0045: newarr [System.Core]System.Linq.Expressions.Expression
IL_004a: stloc.2
IL_004b: ldloc.2
IL_004c: ldc.i4.0
IL_004d: ldc.i4.5
IL_004e: box [mscorlib]System.Int32
IL_0053: ldtoken [mscorlib]System.Int32
IL_0058: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)
IL_005d: call class [System.Core]System.Linq.Expressions.ConstantExpression [System.Core]System.Linq.Expressions.Expression::Constant(object,
class [mscorlib]System.Type)
IL_0062: stelem.ref
IL_0063: ldloc.2
IL_0064: call class [System.Core]System.Linq.Expressions.MethodCallExpression [System.Core]System.Linq.Expressions.Expression::Call(class [System.Core]System.Linq.Expressions.Expression,
class [mscorlib]System.Reflection.MethodInfo,
class [System.Core]System.Linq.Expressions.Expression[])
IL_0069: ldc.i4.1
IL_006a: newarr [System.Core]System.Linq.Expressions.ParameterExpression
IL_006f: stloc.3
IL_0070: ldloc.3
IL_0071: ldc.i4.0
IL_0072: ldloc.1
IL_0073: stelem.ref
IL_0074: ldloc.3
IL_0075: call class [System.Core]System.Linq.Expressions.Expression`1<!!0> [System.Core]System.Linq.Expressions.Expression::Lambda<class [mscorlib]System.Func`2<class C_IL_Difference.Customer,bool>>(class [System.Core]System.Linq.Expressions.Expression,
class [System.Core]System.Linq.Expressions.ParameterExpression[])
IL_007a: call class [System.Core]System.Linq.IQueryable`1<!!0> [System.Core]System.Linq.Queryable::Where<class C_IL_Difference.Customer>(class [System.Core]System.Linq.IQueryable`1<!!0>,
class [System.Core]System.Linq.Expressions.Expression`1<class [mscorlib]System.Func`2<!!0,bool>>)
IL_007f: stloc.0
IL_0080: ldloc.0
IL_0081: call int32 [System.Core]System.Linq.Queryable::Count<class C_IL_Difference.Customer>(class [System.Core]System.Linq.IQueryable`1<!!0>)
IL_0086: call void [mscorlib]System.Console::WriteLine(int32)
IL_008b: nop
IL_008c: ret
} // end of method Program::CallContext
Como parece la versión VB.NET de este código pondrá en contacto con la base de datos cada vez que el código se ejecuta mientras que la versión C# recuperará las entidades de la caché cuando el el código se ejecuta varias veces.
¿Por qué harían que ambos idiomas se comportaran de una manera tan diferente? Era mi concepto erróneo de que ambos lenguajes solo diferían en sintaxis y tenían casi exactamente el mismo IL generado.
¿Hay algún otro ejemplo en el que ambos lenguajes hayan generado una IL tan diferente?
falta 1 y 2 VB código IL fragmentos –
No sé la respuesta, pero si nadie responde ... Me pregunto si es tanto una diferencia de idioma como una diferencia entre la aplicación de Entity Framework para VB vs C#? – user179700
He tenido experiencias similares. Aunque no a prueba total, he encontrado que usar Linq/Lambda en lugar de la sintaxis de consulta anterior es mucho más estrecha en la implementación entre C#/VB. es decir'Dim someEntities = ctx.SomeEntities.Where (Función (n) n.SomeId.Equals (5))' y 'var someEntities = ctx.SomeEntities.Where (n => n.SomeId.Equals (5))' parece obtener un markup IL mucho más cercano. ¿No estoy seguro de si eso ayuda o es relevante? Solo puedo adivinar por qué, pero hay diferencias claras y obvias entre los dos idiomas al usar la sintaxis de la consulta, pero cuando se usa Lambda, ¿puede convertirlos fácilmente/directamente? – Smudge202