问题
I have a simple code that looks like this in C#:
using System;
using System.Threading;
using System.Diagnostics;
namespace ThreadPooling
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Enter the number of calculations to be made:");
int calculations= Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Thread Pool Execution");
for (int i = 1; i <= calculations; i++)
{
Console.WriteLine("Staring process " + i + "...");
ThreadPool.QueueUserWorkItem(new WaitCallback(Process(i)));
}
Console.WriteLine("All calculations done.");
Console.WriteLine("\nPress any key to exit the program...");
Console.ReadKey();
}
static void Process(object callback, int name)
{
for (int i = 0; i <= 10; i++)
{
Console.WriteLine(i + " is the current number in " + name);
}
}
}
}
I want main
to be able to call Process
with Thread Pool and an argument. I then want the program to wait for all threads to finish before telling the user that it is done. How do I do both? It seems I cannot put an argument inside Process, I get: Error CS7036 There is no argument given that corresponds to the required formal parameter 'name' of 'Program.Process(object, int)'
And I am not clear on how to tell C# to wait for all processes with in the loop to finish before it tells the user it is done.
回答1:
.NET is almost 20 years old, and has several generations of improving APIs in it.
This is trivial with the newer Task Parallel Library methods. EG
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
namespace ThreadPooling
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Enter the number of calculations to be made:");
int calculations = Convert.ToInt32(Console.ReadLine());
var tasks = new List<Task>();
for (int i = 1; i <= calculations; i++)
{
int processNum = i;
Console.WriteLine("Staring process " + processNum + "...");
var task = Task.Run(() => Process(processNum));
tasks.Add(task);
}
Task.WaitAll(tasks.ToArray());
Console.WriteLine("All calculations done.");
Console.WriteLine("\nPress any key to exit the program...");
Console.ReadKey();
}
static void Process(int name)
{
for (int i = 0; i <= 10; i++)
{
Console.WriteLine(i + " is the current number in " + name);
}
}
}
}
来源:https://stackoverflow.com/questions/61197591/use-threadpool-in-c-sharp-within-a-loop-and-wait-for-all-threads-to-finish