c# Beginlnvoke 委托

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {

        public delegate void deletask(int num1, int num2);
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            deletask task = new deletask(test);
            int num30 = int.Parse(this.textBox1.Text);
            int num40 = int.Parse(this.textBox2.Text);
            task.BeginInvoke(num30, num40, null, null);
        }

        private void test(int num1, int num2) 
        {
            int sum = 0;
            for (int i = num1; i <= num2; i++) 
            {
                sum += num1;
                num1++;
            }
            this.label1.Text = sum.ToString();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls = false;
        }
    }
}

c# 委托线程返回值

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {

        public delegate int deletask(int num1, int num2);
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            deletask task = test;
            int num3 = int.Parse(this.textBox1.Text);
            int num4 = int.Parse(this.textBox2.Text);
            //task.BeginInvoke(num3, num4, null, null);
            IAsyncResult res = task.BeginInvoke(num3, num4, null, null);
            int result = task.EndInvoke(res);
            this.label1.Text = result.ToString();
        }

        private int test(int num1, int num2) 
        {
            int sum = 0;
            for (int i = num1; i <= num2; i++)  
            {
                sum += num1;
                num1++;
            }
            return sum;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls = false;
        }
    }
}