How to sum up random numbers?

Question

C++ / C#

Need help urgently! How to add values ​​from textbox to label each time the button is pressed (that is, when the button is pressed, a random value from 1 to 100 is displayed in the textbox, and then duplicated in the label immediately, and with the next click a new random value is added) I will be grateful for your help

Answer 1

Create a variable, for example, of type int.
You also create an instance of the Random class to generate numbers.

int number = 0;
Random rn = new Random();

In the button click event:

number += rn.Next(1, 100);
textBox1.Text = number.ToString();
label1.Text = number.ToString();

Everything.

Answer 2

Eh... WinForms. When I remember, I shudder. In ancient times it was something like this:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows.Forms;

using MonadTeq.Toster.UI.Annotations;

namespace MonadTeq.Toster.UI
{
  /// <summary>
  /// An abstraction of view model for data binding.
  /// </summary>
  public abstract class ViewModel
    : INotifyPropertyChanged
  {
    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
      PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    protected bool UpdateProperty<T>(ref T oldValue, T newValue, [CallerMemberName] string propertyName = null)
    {
      if (EqualityComparer<T>.Default.Equals(oldValue, newValue))
      {
        return false;
      }

      oldValue = newValue;
      OnPropertyChanged(propertyName);
      return true;
    }
  }

  /// <summary>
  /// Represents a view model for business logic.
  /// </summary>
  public sealed class RandomSummaryViewModel
    : ViewModel
  {
    private int _accumulatedValue;
    private int _value;

    public RandomSummaryViewModel(int initialValue = 0)
    {
      _accumulatedValue = initialValue;
    }

    public int Value
    {
      get => _value;
      set => UpdateProperty(ref _value, value);
    }

    public int AccumulatedValue
    {
      get => _accumulatedValue;
      set => UpdateProperty(ref _accumulatedValue, value);
    }
  }

  public partial class RandomNumberSumForm : Form
  {
    private readonly RandomSummaryViewModel _vm = new RandomSummaryViewModel();
    private readonly Random _rnd = new Random();

    public RandomNumberSumForm()
    {
      InitializeComponent();

      //
      // Configure data bindings here...
      //

      // Bind text box (id: tbxCurrentRandom) property Text to 'Value' property of RandomSummaryViewModel instance...
      tbxCurrentRandom.DataBindings.Add("Text", _vm, "Value", false, DataSourceUpdateMode.OnPropertyChanged);

      // The same but for label (See logic above)
      lblSum.DataBindings.Add("Text", _vm, "AccumulatedValue", true, DataSourceUpdateMode.OnPropertyChanged);
    }

    private void btnNextRandom_Click(object sender, EventArgs e)
    {
      _vm.Value = _rnd.Next(0, 100);
      _vm.AccumulatedValue += _vm.Value;
    }
  }
}

If you can explain what is happening here and add the amount on the next click, and not instantly - come junior :)