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我正在爲GroupJoin的Linq.Dynamic項目創建擴展方法。但是，由於某種原因，它不會運行。簽名似乎匹配。Linq.Dyanmic GroupJoin implementation
public static IQueryable GroupJoin(this IQueryable outer, IEnumerable inner, string outerSelector, string innerSelector, string resultsSelector, params object[] values)
{
if (inner == null) throw new ArgumentNullException("inner");
if (outerSelector == null) throw new ArgumentNullException("outerSelector");
if (innerSelector == null) throw new ArgumentNullException("innerSelector");
if (resultsSelector == null) throw new ArgumentNullException("resultsSelctor");
LambdaExpression outerSelectorLambda = DynamicExpression.ParseLambda(outer.ElementType, null, outerSelector, values);
Type enumType = GetList(inner.AsQueryable().ElementType).GetType();
LambdaExpression innerSelectorLambda = DynamicExpression.ParseLambda(inner.AsQueryable().ElementType, null, innerSelector, values);
ParameterExpression[] parameters = new ParameterExpression[] {
Expression.Parameter(outer.ElementType, "outer"), Expression.Parameter(enumType, "inner") };
LambdaExpression resultsSelectorLambda = DynamicExpression.ParseLambda(parameters, null, resultsSelector, values);
return outer.Provider.CreateQuery(
Expression.Call(
typeof(Queryable), "GroupJoin",
new Type[] { outer.ElementType, inner.AsQueryable().ElementType, outerSelectorLambda.Body.Type, resultsSelectorLambda.Body.Type },
outer.Expression, inner.AsQueryable().Expression, Expression.Quote(outerSelectorLambda), Expression.Quote(innerSelectorLambda), Expression.Quote(resultsSelectorLambda)));
}
public static IEnumerable GetList(System.Type type)
{
return (IEnumerable)Activator.CreateInstance(typeof(List<>).MakeGenericType(type));
}
此代碼給我下面的錯誤：
No generic method 'GroupJoin' on type 'System.Linq.Queryable' is compatible with the supplied type arguments and arguments. No type arguments should be provided if the method is non-generic.
在看着每片的結果，他們似乎一致： 編寫follwing羣組加入：
man.Contacts.GroupJoin(man.ContactAddresses, param_0 => param_0.ContactId, param_0 => param_0.ContactId,
(outer, inner) => new { ContactId = outer.ContactId, FirstName = outer.FirstName, LastName = outer.LastName, MI = outer.MiddleInitial, ContactAddresses = inner });
我得到調試：
.Call System.Linq.Queryable.GroupJoin(
.Constant<IdeaBlade.EntityModel.EntityQueryProxy`1[LOC.AMP.Data.DomainModel.Contact]>(IdeaBlade.EntityModel.EntityQueryProxy`1[LOC.AMP.Data.DomainModel.Contact]), .Constant<IdeaBlade.EntityModel.EntityQueryProxy`1[LOC.AMP.Data.DomainModel.ContactAddress]>(IdeaBlade.EntityModel.EntityQueryProxy`1[LOC.AMP.Data.DomainModel.ContactAddress]),
'(.Lambda #Lambda1<System.Func`2[LOC.AMP.Data.DomainModel.Contact,System.Int64]>),
'(.Lambda #Lambda2<System.Func`2[LOC.AMP.Data.DomainModel.ContactAddress,System.Int64]>),
'(.Lambda #Lambda3<System.Func`3[LOC.AMP.Data.DomainModel.Contact,System.Collections.Generic.IEnumerable`1[LOC.AMP.Data.DomainModel.ContactAddress], <>f__AnonymousType0`5[System.Int64,System.String,System.String,System.String,System.Collections.Generic.IEnumerable`1[LOC.AMP.Data.DomainModel.ContactAddress]]]>))
.Lambda #Lambda1<System.Func`2[LOC.AMP.Data.DomainModel.Contact,System.Int64]>(LOC.AMP.Data.DomainModel.Contact $param_0)
{
$param_0.ContactId
}
.Lambda #Lambda2<System.Func`2[LOC.AMP.Data.DomainModel.ContactAddress,System.Int64]>(LOC.AMP.Data.DomainModel.ContactAddress $param_0)
{
$param_0.ContactId
}
.Lambda
#Lambda3<System.Func`3
[
LOC.AMP.Data.DomainModel.Contact, System.Collections.Generic.IEnumerable`1[LOC.AMP.Data.DomainModel.ContactAddress],
<>f__AnonymousType0`5
[
System.Int64,System.String,System.String,System.String, System.Collections.Generic.IEnumerable`1
[
LOC.AMP.Data.DomainModel.ContactAddress
]
]
]>
(LOC.AMP.Data.DomainModel.Contact $outer, System.Collections.Generic.IEnumerable`1
[LOC.AMP.Data.DomainModel.ContactAddress] $inner)
{
.New <>f__AnonymousType0`5[System.Int64,System.String,System.String,System.String,System.Collections.Generic.IEnumerable`1[LOC.AMP.Data.DomainModel.ContactAddress]](
$outer.ContactId,
$outer.FirstName,
$outer.LastName,
$outer.MiddleInitial,
$inner)
}
用下面的羣組加入：
man.Contacts.GroupJoin(man.ContactAddresses, "ContactId", "ContactId", "new (outer.ContactId as ContactId, outer.FirstName as FirstName, outer.LastName as LastName, outer.MiddleInitial as MI, inner as ContactAddresses)");
然後看着調試：
.Call GroupJoin (
{value(IdeaBlade.EntityModel.EntityQueryProxy'1[LOC.AMP.Data.DomainModel.Contact])}, {value(IdeaBlade.EntityModel.EntityQueryProxy'1[LOC.AMP.Data.DomainModel.ContactAddress])},
'(.Lambda #Lambda1<System.Func'2[LOC.AMP.Data.DomainModel.Contact,System.Int64]>),
'(.Lambda #Lambda1<System.Func'2[LOC.AMP.Data.DomainModel.ContactAddress,System.Int64]>),
'(.Lambda #Lambda1<System.Func'3[LOC.AMP.Data.DomainModel.Contact,System.Collections.Generic.List`1[LOC.AMP.Data.DomainModel.ContactAddress],DynamicClass1]>)
//ContactId
.Lambda #Lambda1<System.Func'2[LOC.AMP.Data.DomainModel.Contact,System.Int64]>(LOC.AMP.Data.DomainModel.Contact $var1)
{
$var1.ContactId
}
//CA.ContactId
.Lambda #Lambda1<System.Func'2[LOC.AMP.Data.DomainModel.ContactAddress,System.Int64]>(LOC.AMP.Data.DomainModel.ContactAddress $var1)
{
$var1.ContactId
}
//Dynamic Result
.Lambda #Lambda1<System.Func`3[LOC.AMP.Data.DomainModel.Contact,System.Collections.Generic.List`1[LOC.AMP.Data.DomainModel.ContactAddress],DynamicClass1]>(
LOC.AMP.Data.DomainModel.Contact $outer,
System.Collections.Generic.List`1[LOC.AMP.Data.DomainModel.ContactAddress] $inner)
{
.New DynamicClass1(){
ContactId = $outer.ContactId,
FirstName = $outer.FirstName,
LastName = $outer.LastName,
MI = $outer.MiddleInitial,
ContactAddresses = $inner
}
}
唯一不同的是List<T>相比IEnumerable的。但List<T>是IEnumerable。 錯誤讀取像簽名是錯誤的。我無法弄清楚。
任何煽動都會很好。