Access Controls from another class in (WFA) C#

Question

Hey guys,I'm really happy to registered in this forum :) the best forum for c# these days I'm trying to learn and practice OOP in c# , today i want to solve a question... i have this Form1 Then i made a class in a folder called Services i want to code Calculate Button in that class with a void method and then call that method in click event for that Calculate button ... how can i access controls ( labels , buttons , textboxes, ...) in that class called Calculate Tax ? please tell me the thing related to oop for c# thanks !

Mounnad Mohamed · Answer

Hello, I think you don't need to access to User Controls (is not a good practicise) in CalcutateTax class. in CalculateTax class just do methods of your businness (for example calculate tax of employee salary) ,and then just call this methods in Form1.cs Example of Implementation : public class CalculateTax() { const double tax = 0.30; public CalculateTax() { } public double CalculateTax( double salary) { return tax * salary; } } //And Call in Form1.cs public class Form1{ /* ... ... */ CalculateTax calculateTax = new CalculateTax(); double result = calculateTax.CalculateTax(salary); }

Rajanikant Hawaldar · Answer

Hi Armin, in your form implement singleton design pattern and change controls acesss spacifier to public or create property for each control so you can access these controls in other Calculate class through form singleton object. please read it https://www.c-sharpcorner.com/UploadFile/8911c4/singleton-design-pattern-in-C-Sharp/ https://refactoring.guru/design-patterns/singleton https://www.c-sharpcorner.com/UploadFile/akkiraju/singleton-vs-static-classes/

Rajanikant Hawaldar · Answer

Form1 code public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void btnCalculate_Click( object sender, EventArgs e) { float salary = Convert.ToSingle(txtsalary.Text); CalcTax.Instance.ButtonCalculate(salary); } } CalcTax.cs public sealed class CalcTax { public CalcTax() { } private static readonly Lazy instance = new Lazy (() => new CalcTax()); public static CalcTax Instance { get { return instance.Value; } } public void ButtonCalculate( float Salary) { double tax; if (Salary tax = 0; else if (Salary tax = Salary * 0.05; else if (Salary tax = Salary * 0.05; else if (Salary tax = Salary * 0.15; else tax = Salary * 0.05; } } you can change as per your requirements, @Note in void method you can set values to property / controls but creating form object at comman reusable class is wrong, comman class is abstract, it can be static or public / or can use by implementing singleton pattern, everything based on requirement and design is important so read oops... corrent me if i am wrong / wrong understanding.

Rajanikant Hawaldar · Answer

@Armin your doing reverse, Implement singleton pattern in CalcTax class access ButtonCalculate function at your form1 class and pass parameter Salary to ButtonCalculate. Please read Oops concept, you CalcTax is comman class, reusable to access ButtonCalculate at any other forms ro classes

Armin CSharp · Answer

is this true way ? then after that