用c#实现多线程拷贝文件

Question

多线程拷贝文件根本就没多大意义....
磁盘的写入是同步了的和单线程效果一样.

Answer 1

给你个例子，主要是那个oCopyFile函数。以及button3_click里的动作。关键就是文件拆分，以及多线程处理。
但却是没什么意义。小文件速度体现不出来，大文件要先分配磁盘空间才能开始复制，反而慢。
这是以前给别人做的毕业设计，写的比较乱，将就下吧        static float[] statusi;
        static long[] postion;
        static int cachNum = 1024 * 4096;
        static string f1;
        static bool chkway = true;
        static string f2;
        static int part = 5;
        static bool stop = false;
        static checkpoint cp;
        static int picksize = 1024;
        static float pctpause = -1;
        static int arrypart = 1;
        static writelogs log;
        DateTime startime;
/// <summary>
        /// 复制从传入的起始位置开始到该进程总共需要复制的长度的数据流
        /// </summary>
        /// <param name="ostar">所需的传输的参数，包括起始位置</param>
        public static void oCopyFile(object ostar)
        {
            FileStream src = File.Open(f1, FileMode.Open, FileAccess.Read, FileShare.Read);
            FileStream des = File.Open(f2, FileMode.OpenOrCreate, FileAccess.Write, FileShare.Write);
            long sl = (long)(src.Length / part);
            long size = sl + (src.Length % part == 0 ? 0 : 1);
            object[] slst = ((System.Collections.ArrayList)ostar).ToArray();
            int pos = (int)slst[0];
            long star;
            if ((long)slst[1] == (long)0)
            {
                star = pos * size;
            }
            else if ((long)slst[1] < 0)
            {
                star = src.Length / arrypart * (long)(-(long)slst[1] / (src.Length / arrypart));
                size = size - (star - pos * size);
            }
            else
            {
                star = (long)slst[1];
                size = size - (star - pos * size);
            }
            //开始复制文件
            //每次读取一定大小的数据
            for (long i = star; i < star + size; i = i + picksize)
            {
                postion[pos] = i;
                if (stop) break;
                byte[] b = new byte[(star + size - i) > picksize ? picksize : (star + size - i)];//(byte)src.ReadByte();
                //stopT(pos);
                src.Position = i;
                src.Read(b, 0, b.Length);
                des.Position = i;
                if (src.Length < b.Length + i)
                    des.Write(b, 0, b.Length - 1);
                else
                    des.Write(b, 0, b.Length);
                //starTs();                //checkpoint方式时
                if (!chkway)
                {
                    if (postion[pos] / (long)(src.Length / arrypart) < picksize)
                    {
                        cp.UpdatePoint(f1, f2, postion);
                    }
                }
                //数组方式时
                if ((i - star) % cachNum == 0)
                {
                    des.Flush();
                    if (chkway)
                    { cp.UpdatePoint(f1, f2, postion); }
                }                if (pctpause > 0)
                {
                    if (((int)(((float)(i - star)) / size * 10000)) >= (int)(pctpause * 100))
                    {
                        statusi[pos] = pctpause;
                        //更新ｃｈｅｃｋｐｏｉｎｔ
                        if (chkway) cp.UpdatePoint(f1, f2, postion);
                        des.Flush();
                        src.Close();
                        des.Close();
                        stop = true;
                        return;
                    }                }
                if(statusi.Length==1)
                    statusi[pos] = (int)(((float)(i)) / (sl) * 100);
                else
                    statusi[pos] = (int)(((float)(i - star)) / (size) * 100);
            }            des.Flush();
            if (!stop) statusi[pos] = 101;
            cp.UpdatePoint(f1, f2, postion);
            src.Close();
            des.Close();
        }        private void button3_Click(object sender, EventArgs e)
        {
            if (textBox1.Text == "" || textBox2.Text == "")
            {
                MessageBox.Show("请选择要复制的文件以及目的地。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }
            if (File.Exists(textBox2.Text)) File.Delete(textBox2.Text);
            if (checkBox1.Checked)
            {
                pctpause = (float)numericUpDown5.Value;
                numericUpDown1.Value = 1;
            }
            else
            {
                pctpause = -1;
            }
            f1 = textBox1.Text;
            f2 = textBox2.Text;
            part = (int)numericUpDown1.Value;
            cachNum = (int)(1024 * 1024 * numericUpDown2.Value);
            statusi = new float[part];
            postion = new long[part];
            Thread[] t = new Thread[part];
            listBox1.Items.Clear();
            stop = false;
            startime = DateTime.Now;
            arrypart = (int)numericUpDown6.Value;
            picksize = (int)numericUpDown4.Value * 1024;
            for (int j = 0; j < t.Length; j++)
            {
                System.Collections.ArrayList al = new System.Collections.ArrayList();
                al.Add(j);
                al.Add((long)0);
                t[j] = new Thread(Form1.oCopyFile);
                t[j].Start(al);
                listBox1.Items.Add("线程 " + (j + 1).ToString() + ": 正在启动");
            }
            log.AddLogs("开始复制", new float[] {0 }, f1,f2);
            timer1.Enabled = true;
            cp.AddPoint(f1, f2, postion);
            numericUpDown1.Enabled = false;
            numericUpDown4.Enabled = false;
            button3.Enabled = false;
            button4.Enabled = true;
            dataGridView1.Enabled = false;
            radioButton1.Enabled = false;
            radioButton2.Enabled = false;
            numericUpDown5.Enabled = false;
            numericUpDown6.Enabled = false;
            checkBox1.Enabled = false;
        }
 
    }
}