C#•7mo ago

Delegate with Task problem

I decided to work with delegates. I chose to do different kinds of sorting. I made a Sort class, where the name and the SortMethod response are located, but when I started to look at the results, I saw that the sorting that was not performed until that moment of output is simply not output (an error appears on result = null). Does anyone know why var result = await sortDelegate.SortMethod; doesn't work?

6 Replies

TreF01LOP•7mo ago

public class SortStopwatch
{
    public delegate Task<MethodResponse> SortMethod();

    private List<SortDelegate> _sortsList = new List<SortDelegate>();
    private List<SortDelegate> _sortsListToShow = new List<SortDelegate>();
    private int[] _array;

    public SortStopwatch()
    {
        InitializeArray();
        InitializeSortsList();
        ShowMainMenu();
    }

    private void InitializeArray()
    {
        Console.WriteLine("Enter length of random array: ");
        if (!int.TryParse(Console.ReadLine(), out int length) || length <= 0)
        {
            Console.WriteLine("Your length is incorrect! Try again");
            InitializeArray();
        }

        _array = ArrayGenerator.GenerateRandomArray(length);
    }

    private void InitializeSortsList()
    {
        _sortsList.Add(new SortDelegate(nameof(BubbleSort), 
            Task.Run(async () => await SortMethodFunction(BubbleSort.Sort, (int[])_array.Clone(), nameof(BubbleSort))))); 
        
        _sortsList.Add(new SortDelegate(nameof(ChickenSort) + " (Be careful! If you add it when the array length > 50, it will take some more time to sort it)", 
            Task.Run(async () => await SortMethodFunction(ChickenSort.Sort, (int[])_array.Clone(), nameof(ChickenSort))))); 
    }

    private async Task<MethodResponse> SortMethodFunction(Func<int[], Task<int[]>> function, int[] array, string methodName)
    {
        Stopwatch stopwatch = Stopwatch.StartNew();
        var result = await function(array);
        
        stopwatch.Stop();
        return new MethodResponse()
        {
            Name = methodName,
            Time = stopwatch.Elapsed,
            Array = result
        };
    }

    

        
        
    }

public class SortStopwatch
{
    public delegate Task<MethodResponse> SortMethod();

    private List<SortDelegate> _sortsList = new List<SortDelegate>();
    private List<SortDelegate> _sortsListToShow = new List<SortDelegate>();
    private int[] _array;

    public SortStopwatch()
    {
        InitializeArray();
        InitializeSortsList();
        ShowMainMenu();
    }

    private void InitializeArray()
    {
        Console.WriteLine("Enter length of random array: ");
        if (!int.TryParse(Console.ReadLine(), out int length) || length <= 0)
        {
            Console.WriteLine("Your length is incorrect! Try again");
            InitializeArray();
        }

        _array = ArrayGenerator.GenerateRandomArray(length);
    }

    private void InitializeSortsList()
    {
        _sortsList.Add(new SortDelegate(nameof(BubbleSort), 
            Task.Run(async () => await SortMethodFunction(BubbleSort.Sort, (int[])_array.Clone(), nameof(BubbleSort))))); 
        
        _sortsList.Add(new SortDelegate(nameof(ChickenSort) + " (Be careful! If you add it when the array length > 50, it will take some more time to sort it)", 
            Task.Run(async () => await SortMethodFunction(ChickenSort.Sort, (int[])_array.Clone(), nameof(ChickenSort))))); 
    }

    private async Task<MethodResponse> SortMethodFunction(Func<int[], Task<int[]>> function, int[] array, string methodName)
    {
        Stopwatch stopwatch = Stopwatch.StartNew();
        var result = await function(array);
        
        stopwatch.Stop();
        return new MethodResponse()
        {
            Name = methodName,
            Time = stopwatch.Elapsed,
            Array = result
        };
    }

    

        
        
    }

private async void RunAndCompareSortMethodMenu(string? errorMessage = null)
    {
        try
        {
            foreach (var sortDelegate in _sortsListToShow)
            {
                var result = await sortDelegate.SortMethod;
                Console.WriteLine($"Name: {result.Name} Time: {result.Time}");
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
            throw;
        }

private async void RunAndCompareSortMethodMenu(string? errorMessage = null)
    {
        try
        {
            foreach (var sortDelegate in _sortsListToShow)
            {
                var result = await sortDelegate.SortMethod;
                Console.WriteLine($"Name: {result.Name} Time: {result.Time}");
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
            throw;
        }

reflectronic•7mo ago

i think we will need to see the full code you can $paste it

MODiX•7mo ago

If your code is too long, you can post to https://paste.mod.gg/ and copy the link into chat for others to see your shared code!

TreF01LOP•7mo ago

https://paste.mod.gg/lldfmlogsxih/0

BlazeBin - lldfmlogsxih

A tool for sharing your source code with the world!

TreF01LOP•7mo ago

I pasted all code

reflectronic•7mo ago

sorry, i took a nap right after asking for the code

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Delegate with Task problem