docs/fundamentals/runtime-libraries/snippets/System/Exception/Overview/csharp/rethrow3.cs - main - aprogrammer/dotnet-docs

docs/fundamentals/runtime-libraries/snippets/System/Exception/Overview/csharp/rethrow3.cs
96 строк3 KB
Genevieve Warren
Remarks for exception types and Registry class (#38930)
03 янв 2024, 22:30
03 янв 2024, 22:30932bcca
using System;
using System.Collections.Generic;

static class Library
{
    public static int[] FindOccurrences1(this String s, String f)
    {
        var indexes = new List<int>();
        int currentIndex = 0;
        try
        {
            while (currentIndex >= 0 && currentIndex < s.Length)
            {
                currentIndex = s.IndexOf(f, currentIndex);
                if (currentIndex >= 0)
                {
                    indexes.Add(currentIndex);
                    currentIndex++;
                }
            }
        }
        catch (ArgumentNullException e)
        {
            // Perform some action here, such as logging this exception.
            // <Snippet8>
            throw new ArgumentNullException("You must supply a search string.", e);
            // </Snippet8>
        }
        return indexes.ToArray();
    }
}

public class RethrowEx3
{
    public static void Main()
    {
        String s = "It was a cold day when...";
        int[] indexes = s.FindOccurrences1("a");
        ShowOccurrences(s, "a", indexes);
        Console.WriteLine();

        String toFind = null;
        // <Snippet9>
        try
        {
            indexes = s.FindOccurrences(toFind);
            ShowOccurrences(s, toFind, indexes);
        }
        catch (ArgumentNullException e)
        {
            Console.WriteLine("An exception ({0}) occurred.",
                              e.GetType().Name);
            Console.WriteLine("   Message:\n{0}", e.Message);
            Console.WriteLine("   Stack Trace:\n   {0}", e.StackTrace);
            Exception ie = e.InnerException;
            if (ie != null)
            {
                Console.WriteLine("   The Inner Exception:");
                Console.WriteLine("      Exception Name: {0}", ie.GetType().Name);
                Console.WriteLine("      Message: {0}\n", ie.Message);
                Console.WriteLine("      Stack Trace:\n   {0}\n", ie.StackTrace);
            }
        }
        // The example displays the following output:
        //    'a' occurs at the following character positions: 4, 7, 15
        //
        //    An exception (ArgumentNullException) occurred.
        //       Message: You must supply a search string.
        //
        //       Stack Trace:
        //          at Library.FindOccurrences(String s, String f)
        //       at Example.Main()
        //
        //       The Inner Exception:
        //          Exception Name: ArgumentNullException
        //          Message: Value cannot be null.
        //    Parameter name: value
        //
        //          Stack Trace:
        //          at System.String.IndexOf(String value, Int32 startIndex, Int32 count, Stri
        //    ngComparison comparisonType)
        //       at Library.FindOccurrences(String s, String f)
        // </Snippet9>
    }

    private static void ShowOccurrences(String s, String toFind, int[] indexes)
    {
        Console.Write("'{0}' occurs at the following character positions: ",
                      toFind);
        for (int ctr = 0; ctr < indexes.Length; ctr++)
            Console.Write("{0}{1}", indexes[ctr],
                          ctr == indexes.Length - 1 ? "" : ", ");

        Console.WriteLine();
    }
}