Sign Up

Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.

Have an account? Sign In

Have an account? Sign In Now

Sign In

Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.

Sign Up Here

Forgot Password?

Don't have account, Sign Up Here

Forgot Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

Have an account? Sign In Now

You must login to ask question.(5)

Forgot Password?

Need An Account, Sign Up Here

Please briefly explain why you feel this question should be reported.

Please briefly explain why you feel this answer should be reported.

Please briefly explain why you feel this user should be reported.

Sign InSign Up

ITtutoria

ITtutoria Logo ITtutoria Logo

ITtutoria Navigation

  • Python
  • Java
  • Reactjs
  • JavaScript
  • R
  • PySpark
  • MYSQL
  • Pandas
  • QA
  • C++
Ask A Question

Mobile menu

Close
Ask a Question
  • Home
  • Python
  • Science
  • Java
  • JavaScript
  • Reactjs
  • Nodejs
  • Tools
  • QA
Home/ Questions/Is it okay to fix the extension method must be defined in a non-generic static class in c# problem?
Next
Answered
Molly Byrne
  • 24
Molly Byrne
Asked: May 18, 20222022-05-18T16:51:07+00:00 2022-05-18T16:51:07+00:00In: csharp

Is it okay to fix the extension method must be defined in a non-generic static class in c# problem?

  • 24

. Advertisement .

..3..

. Advertisement .

..4..

Here is the program I run:

public class LinqHelper
using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Linq.Expressions;
 using System.Reflection;
 
 /// <summary>
 /// Helper methods for link
 /// </summary>
 public class LinqHelper
 {
  public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string property)
  {
  return ApplyOrder<T>(source, property, "OrderBy");
  }
  public static IOrderedQueryable<T> OrderByDescending<T>(this IQueryable<T> source, string property)
  {
  return ApplyOrder<T>(source, property, "OrderByDescending");
  }
  public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> source, string property)
  {
  return ApplyOrder<T>(source, property, "ThenBy");
  }
  public static IOrderedQueryable<T> ThenByDescending<T>(this IOrderedQueryable<T> source, string property)
  {
  return ApplyOrder<T>(source, property, "ThenByDescending");
  }
  static IOrderedQueryable<T> ApplyOrder<T>(IQueryable<T> source, string property, string methodName)
  {
  string[] props = property.Split('.');
  Type type = typeof(T);
  ParameterExpression arg = Expression.Parameter(type, "x");
  Expression expr = arg;
  foreach (string prop in props)
  {
  // use reflection (not ComponentModel) to mirror LINQ
  PropertyInfo pi = type.GetProperty(prop);
  expr = Expression.Property(expr, pi);
  type = pi.PropertyType;
  }
  Type delegateType = typeof(Func<,>).MakeGenericType(typeof(T), type);
  LambdaExpression lambda = Expression.Lambda(delegateType, expr, arg);
 
  object result = typeof(Queryable).GetMethods().Single(
  method => method.Name == methodName
  && method.IsGenericMethodDefinition
  && method.GetGenericArguments().Length == 2
  && method.GetParameters().Length == 2)
  .MakeGenericMethod(typeof(T), type)
  .Invoke(null, new object[] { source, lambda });
  return (IOrderedQueryable<T>)result;
  }
 }

After I run, it returns an error:

Extension methods must be defined in a non-generic static class

Does anyone have any suggestions for the problem below: extension method must be defined in a non-generic static class in C# in the csharp – How to correct it?

non-generic static class
  • 2 2 Answers
  • 94 Views
  • 0 Followers
  • 0
Answer
Share
  • Facebook
  • Report

2 Answers

  • Voted
  • Oldest
  • Recent
  • Random
  1. Best Answer
    dttutoria Expert
    2022-06-19T06:14:13+00:00Added an answer on June 19, 2022 at 6:14 am

    The cause: As you know, when developing an extension method, you must notice:
    – The extension method’s defining class needs to be non-generic, static, and non-nested.
    – There must be a static method for every extension method.
    – The extension method’s first parameter needs to contain the keyword this.

    Lack of the keyword static in the class declaration is the problem in your code:

    Solution:

    change:

    public class LinqHelper
     

    into:

    public static class LinqHelper
    • 0
    • Reply
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
      • Report
  2. Chloë Gallet
    2022-05-25T20:34:30+00:00Added an answer on May 25, 2022 at 8:34 pm

    If you don’t want static functions, just remove the “this” keyword from the arguments.

    • 16
    • Reply
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
      • Report

Leave an answer
Cancel reply

You must login to add an answer.

Forgot Password?

Need An Account, Sign Up Here

Sidebar

Ask A Question
  • How to Split String by space in C++
  • How To Convert A Pandas DataFrame Column To A List
  • How to Replace Multiple Characters in A String in Python?
  • How To Remove Special Characters From String Python

Explore

  • Home
  • Tutorial

Footer

ITtutoria

ITtutoria

This website is user friendly and will facilitate transferring knowledge. It would be useful for a self-initiated learning process.

@ ITTutoria Co Ltd.

Tutorial

  • Home
  • Python
  • Science
  • Java
  • JavaScript
  • Reactjs
  • Nodejs
  • Tools
  • QA

Legal Stuff

  • About Us
  • Terms of Use
  • Privacy Policy
  • Contact Us

DMCA.com Protection Status

Help

  • Knowledge Base
  • Support

Follow

© 2022 Ittutoria. All Rights Reserved.

Insert/edit link

Enter the destination URL

Or link to existing content

    No search term specified. Showing recent items. Search or use up and down arrow keys to select an item.