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Reflection: a method with a common argument and a lambda expression as a parameter

I really can't figure it out ...

I am trying to achieve the following result using reflection:

_builder.Entity<Post>().HasKey(p => p.Id);

Let me introduce variables ... _builderhas a type DbModelBuilder, but Posthas a Idtype property Guid.

The code below contentTypewraps System.Type:

var config = _builder.GetType()
    .GetMethod("Entity")
    .MakeGenericMethod(contentType.Type)
    .Invoke(_builder, null);

var hasKey = config.GetType().GetMethod("HasKey");

var expressionKey = typeof(Expression<>)
    .MakeGenericType(typeof(Func<,>)
    .MakeGenericType(contentType.Type, typeof(Guid)));

var paramEx = Expression.Parameter(contentType.Type, "t");
var lambdaEx = Expression.Lambda(Expression.Property(paramEx, "Id"), paramEx);

hasKey.MakeGenericMethod(typeof(Guid))
    .Invoke(_builder, new[] { lambdaEx });

HasKey may I help:

public EntityTypeConfiguration<TEntityType> HasKey<TKey>(Expression<Func<TEntityType, TKey>> keyExpression);

... where TEntityTypeshould have type Postand TKeytype Guid...

A type exception is TargetExceptionthrown (the last time Invoke was called above):

The object does not match the type of target.

I tried all the ideas that I could come up with, and yet I cannot match the type of goal.

Any help is appreciated.

+5
2

Invoke . "config", "_builder"

+2

, ...

:

var config = _builder.GetType()
    .GetMethod("Entity")
    .MakeGenericMethod(contentType.Type)
    .Invoke(_builder, null);

var hasKey = config.GetType().GetMethod("HasKey");

var expressionKey = typeof(Expression<>)
    .MakeGenericType(typeof(Func<,>)
    .MakeGenericType(contentType.Type, typeof(Guid)));

var paramEx = Expression.Parameter(contentType.Type, "t");
var lambdaEx = Expression.Lambda(Expression.Property(paramEx, "Id"), paramEx);

hasKey.MakeGenericMethod(typeof(Guid))
    .Invoke(config, new[] { lambdaEx });
0

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