Having trouble compiling code-first EF4 class in runtime :)

Question

I'm try to compile this code at run time. this code is a code-first EF4 class.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel.DataAnnotations;

namespace EFCodeFirst.Model.Models
{
    [Table("Blog")]
    public class Blog
    {
        public Guid Id { get; set; }
        [Column("txtTitle")]
        public string Title { get; set; }
        [DatabaseGenerated(DatabaseGeneratedOption.None)]
        public string ShortTitle { get { return Title; } }
        public string BloggerName { get; set; }
        public virtual ICollection<Post> Posts { get; set; }
    }

    public class Post
    {
        public Guid Id { get; set; }
        public string Title { get; set; }
        public DateTime DateCreated { get; set; }
        public string Content { get; set; }
        public Guid BlogId { get; set; }
    }
}

using this method that compile the given code. I tested this code with a simple class. it works. but with given class, it doesn't work at all.

private Assembly BuildAssembly(string code)
        {
            Microsoft.CSharp.CSharpCodeProvider provider = new CSharpCodeProvider();
            ICodeCompiler compiler = provider.CreateCompiler();
            CompilerParameters compilerparams = new CompilerParameters();
            compilerparams.GenerateExecutable = false;
            compilerparams.GenerateInMemory = true;
            CompilerResults results = compiler.CompileAssemblyFromSource(compilerparams, code);
            if (results.Errors.HasErrors)
            {
                StringBuilder errors = new StringBuilder("Compiler Errors :\r\n");
                foreach (CompilerError error in results.Errors)
                {
                    errors.AppendFormat("Line {0},{1}\t: {2}\n", error.Line, error.Column, error.ErrorText);
                }
                throw new Exception(errors.ToString());
            }
            else
            {
                return results.CompiledAssembly;
            }
        }

and i'm getting some exceptions like this:

error CS0234: The type or namespace name 'Linq' does not exist in the namespace 'System' (are you missing an assembly reference?)}

Any help?

Thank you.

Answer 1

Seems like you don't have in 'compilerparams' ReferencedAssemblies set up. Most likely you need to add the necessary assembly references like you would add in a normal VS C# project. Try adding them in your BuildAssembly method using something like:

compilerparams.ReferencedAssemblies.Add("mscorlib.dll"); compilerparams.ReferencedAssemblies.Add("System.dll"); compilerparams.ReferencedAssemblies.Add("System.Core.dll"); compilerparams.ReferencedAssemblies.Add("System.Xml.dll"); compilerparams.ReferencedAssemblies.Add("EntityFramework.dll");

Besides this, make sure you have the following namespace usings in the code that you want to compile: using System.Data.Entity; using System.Collections.Generic; using System.ComponentModel.DataAnnotations; using System.Data.Entity; using System.Collections.Generic; using System.ComponentModel.DataAnnotations; This should solve your compilation problems regarding this matter.

Answer 2

I also met this problem, and upgrade website from NET 4.0 to NET 4.6.1, it's fixed. Remember to remove NUGET components and reinstall in new NET target new version.