Silverlight 5, ria services with entity framework 6.0 alpha 3




I am trying to create a silverlight 5.0 application using ria services, with entityframework 6.0 alpha 3. This is a greenfield project that never used any other version of entityframework. Everything seems to compile fine, except for the silverlight data project that connects to the web project to generate proxies. I get the following error:


Error 2 Method not found: 'System.Data.Objects.ObjectContext System.Data.Entity.Infrastructure.IObjectContextAdapter.get\_ObjectContext()'


Is there an incompatibility or am I just doing something wrong?
RIA Services [is now OpenSource](http://jeffhandley.com/archive/2013/07/03/ria-services-is-getting-open-sourced.aspx) with the name "Open RIA Services" (see [on CodePlex](https://openriaservices.codeplex.com/)).


Colin Blair, the project leader, has just announced the first version with EF6 support :
<http://www.openriaservices.net/blog/post/The-Open-RIA-Services-Blog/1016/4-3-Alpha-NuGet-Packages-Released/>


You can install the Nuget package : [RIA Services for Entity Framework 6+](https://www.nuget.org/packages/RIAServicesContrib.EntityFramework).


~~If you want to install the Nuget package [RIA Services for Entity Framework 6+](https://www.nuget.org/packages/RIAServicesContrib.EntityFramework), be sure to select the "include prerelease" item in the top combo Box.~~
hi andrew penny, - - just add this namespace definition: - xmlns:system=clr-namespace:system;assembly=mscorlib - - there are differences in parsing between wpf and silverlight and that is the reason we used the syntax below. if you develop silverlight application you can set it as follows: - - discreteobjectkeyframe keytime=0.00:00:00.0 value=2 /> - - - best wishes, - sia - the telerik team - - - do you want to have your say when we set our development plans? - do you want to know when a feature you care about is added or when a bug fixed? - explore the - telerik public issue tracking - system and vote to affect the priority of the items - - try this version:

<https://drive.google.com/file/d/1ffegjdy1563skl8qrnxtcngwg4vra_7-/view?usp=sharing>

we’re still working through some compatibility issues with the new os. it seems if i use the framework version that solves some of the visual glitches it messes up camera compatibility. You are mixing [expressions](https://docs.microsoft.com/en-us/dotnet/api/system.linq.expressions.expression?view=netframework-4.7.1) with [lambda expressions](https://docs.microsoft.com/en-us/dotnet/api/system.linq.expressions.lambdaexpression?view=netframework-4.7.1). There are many posts showing how you can combine lambda expressions, but the essential part is to compose expressions from lambda expression [bodies](https://docs.microsoft.com/en-us/dotnet/api/system.linq.expressions.lambdaexpression.body?view=netframework-4.7.1) and rebind the [parameters](https://docs.microsoft.com/en-us/dotnet/api/system.linq.expressions.lambdaexpression.parameters?view=netframework-4.7.1).


The later is usually achieved by a custom [`ExpressionVisitor`](https://docs.microsoft.com/en-us/dotnet/api/system.linq.expressions.expressionvisitor?view=netframework-4.7.1) like this:



```
using System.Linq.Expressions;

public static class ExpressionExtensions
{
    public static Expression ReplaceParameter(this Expression expression, ParameterExpression source, Expression target)
    {
        return new ParameterReplacer { Source = source, Target = target }.Visit(expression);
    }

    class ParameterReplacer : ExpressionVisitor
    {
        public ParameterExpression Source;
        public Expression Target;
        protected override Expression VisitParameter(ParameterExpression node)
        {
            return node == Source ? Target : base.VisitParameter(node);
        }
    }
}

```

Now regarding the EF Core combined query filters. 


Using dictionaries and expression lists seems overcomplicated for what are you doing. Since [`IMutableEntityType`](https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.metadata.imutableentitytype?view=efcore-2.1) provides read/write access to the [`QueryFilter`](https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.metadata.imutableentitytype.queryfilter?view=efcore-2.1#Microsoft_EntityFrameworkCore_Metadata_IMutableEntityType_QueryFilter), the same can be achieved with a small set of a custom extension methods.


All they go inside a class like this:



```
using System;
using System.Linq.Expressions;
using Microsoft.EntityFrameworkCore.Metadata;
using Microsoft.EntityFrameworkCore.Metadata.Builders;

public static class QueryFilterExtensions
{
}

```

First method:



```
public static void AddQueryFilter(this IMutableEntityType target, LambdaExpression filter)
{
    if (target.QueryFilter == null)
        target.QueryFilter = filter;
    else
    {
        var parameter = target.QueryFilter.Parameters[0];
        var left = target.QueryFilter.Body;
        var right = filter.Body.ReplaceParameter(filter.Parameters[0], parameter);
        var body = Expression.AndAlso(left, right);
        target.QueryFilter = Expression.Lambda(body, parameter);
    }
}

```

This is a non generic method which combines the exiting filter with passed filter using `AndAlso` (C# `&&`) operator and shows the aforementioned lambda expression combining principles.


However it's not so useful directly, like inside your entity type configuration loop (it can, but requires you to build manually the lambda expression instead of letting C# compiler do that). So here comes the second method:



```
public static void AddQueryFilter<T>(this IMutableEntityType target, Expression<Func<T, bool>> filter)
{
    LambdaExpression targetFilter = filter;
    if (target.ClrType != typeof(T))
    {
        var parameter = Expression.Parameter(target.ClrType, "e");
        var body = filter.Body.ReplaceParameter(filter.Parameters[0], parameter);
        targetFilter = Expression.Lambda(body, parameter);
    }
    target.AddQueryFilter(targetFilter);
}

```

It's a generic method - not quite type-safe, but allows you to use a compile time lambda expression and bind it to the actual entity type as follows:



```
foreach (var entityType in modelBuilder.Model.GetEntityTypes())
{
    if (typeof(IDeleted).IsAssignableFrom(entityType.ClrType))
        entityType.AddQueryFilter<IDeleted>(e => e.DateTimeDeleted == null);
}

```

Looks better, isn't it :)


The last custom extension method is complement to (replacement of) the standard EF Core generic [`HasQueryFilter`](https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.metadata.builders.entitytypebuilder-1.hasqueryfilter?view=efcore-2.1#Microsoft_EntityFrameworkCore_Metadata_Builders_EntityTypeBuilder_1_HasQueryFilter_System_Linq_Expressions_Expression_System_Func__0_System_Boolean___) method:



```
public static EntityTypeBuilder<TEntity> AddQueryFilter<TEntity>(this EntityTypeBuilder<TEntity> target, Expression<Func<TEntity, bool>> filter)
    where TEntity : class
{
    target.Metadata.AddQueryFilter(filter);
    return target;
}

```

and allows you to replace



```
this.AddToDict<DbMyEntity>(t => t.Name == null || t.Name == "Something");

```

with the more convenient



```
modelBuilder.Entity<DbMyEntity>()
    .AddQueryFilter(t => t.Name == null || t.Name == "Something");

```

**Update (EF Core 3.0):** `QueryFilter` property has been replaced with `GetQueryFilter` and `SetQueryFilter` extension methods. hola, acabo de solucionar mi problema

problema:

[unhandled promise rejection: error: no native splash screen registered for provided activity. please configure your application’s main activity to call ‘splashscreen.show’ ([https://github.com/expo/expo/tree/master/packages/expo-splash-screen#-config…](https://github.com/expo/expo/tree/master/packages/expo-splash-screen#-configure-android) hmm…i wonder why it didnt

fine buddy

is it community edition or enterprise edition

if its enterprise edition of orchestrator kindly raise a ticket to technical team

[image]

[contact technical support](https://www.uipath.com/company/contact-us/contact-technical-support)

contact uipath technical support department.

cheers [@brun…](/u/bruno_silveira_uy) I have the same problem and added this to the DbContext:



```
private void PrintStackTrace()
{
  var st = new StackTrace();
  foreach (var sf in st.GetFrames())
    Console.WriteLine($"{sf.GetMethod().DeclaringType.Assembly.GetName().Name} {sf.GetMethod().DeclaringType.Name} {sf.GetMethod().Name}");
}

```

and call this function in the contructor and Dispose of the DbContext.


It seems to be a problem, if the DbContext is added with scoped lifetime to the dependency injection. I filed an issue for that.


<https://github.com/aspnet/EntityFrameworkCore/issues/10693> solution to my problem.

install python enabling framework and then do the rest of the installation as defined

python\_configure\_opts="--enable-framework" pyenv install 3.6.8

the issue was with wx and the need for a framework

when running a simple ws app

import wx

app = wx.app(false) # create a… for posterity, the issue was a different environment was being used in the ijulia notebook, which contained pavito, causing jump to downgrade.

for others finding this, here is the documentation on pkg environments:

[image]

[4. working with environments · pkg.jl](https://julialang.github.io/pkg.jl/v1/environments/) hi [@kkutter](/u/kkutter),

can you provide a little more context as to what your goals are?

confluence makes aui’s buttons available through their product. since aui 7.2, aui’s buttons are styled with an alpha-transparent background colour so that they appear on light grey backgrounds.

check this codepen: [http…](https://codepen.io/chrisdarroch/pen/wkeyga) Entity Framework Core does not have lazy loading implemented at this time (RTM Build).


It is recommended that you do eager loading by using an .Include extension method. It is also a good idea to use a repository to do the eager loading for you.


Reference: <https://github.com/aspnet/EntityFramework/issues/3797>