FileStrem大文件分割复制

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace FileStrem大文件分割复制
{
    public partial class Form1 : Form
    {
        private int WriterByetNub = 104857600;//100M复制速度
        //源目标
        private FileStream FileToRead;
        //复制到文件
        private FileStream FileToWrite;
        //保存文件的地址
        private string SaveFile_Add;
        //源文件的名字
        private string File_Add;
        //设置正常写入字节
        private Byte[] byteToWrite;
        //设置剩余写入字节
        private Byte[] byteToLastWrite;
        //循环次数
        private long WriteTimes;
        //循环后的剩余字节
        private int L_Size;

        public Form1()
        {
            InitializeComponent();
        }
        //设置委托
        private delegate void OpenFile();

        private void Cpy()
        {
            try
            {
                label_Add.Text = "源地址";

                label_Cpy_Add.Text = "复制到";

                label_Cpy_Lc.Text = "复制进程:";

                label_Write.Text = "已经写入";

                label_FileSize.Text = "源文件总大小";
                //文件选取
                OpenFileDialog openfileDialog = new OpenFileDialog();
                //show文件选取器
                openfileDialog.ShowDialog();

                File_Add = openfileDialog.FileName;

                label_Add.Text += "：" + File_Add;
                
                //保存地址选取
                FolderBrowserDialog savefileDialog = new FolderBrowserDialog();

                savefileDialog.ShowDialog();

                SaveFile_Add = savefileDialog.SelectedPath;

                label_Cpy_Add.Text += "：" + SaveFile_Add + File_Add;

                FileToRead = new FileStream(File_Add, FileMode.Open, FileAccess.Read);

                FileToWrite = new FileStream(@SaveFile_Add + "\\" + openfileDialog.SafeFileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);

                label_FileSize.Text = "源文件总大小"+(FileToRead.Length/1024).ToString()+"KB";
                if (FileToRead.Length > WriterByetNub)
                //设置写入字节数组
                {
                    byteToWrite = new byte[WriterByetNub];
                    //循环次数
                    WriteTimes = FileToRead.Length / WriterByetNub;
                    //多次循环后剩余字节
                    L_Size = Convert.ToInt32(FileToRead.Length % WriterByetNub);
                    //多次循环后字节数组
                    byteToLastWrite = new byte[L_Size];

                    for (long i = 0; i <= WriteTimes; i++)
                    {
                        //读源文件
                        FileToRead.Read(byteToWrite, 0, WriterByetNub);

                        //写数据到目标文件
                        FileToWrite.Write(byteToWrite, 0, WriterByetNub);

                        //设置进度条的值
                        progressBar.Value = Convert.ToInt32(i * 100 / WriteTimes);

                        Application.DoEvents();

                        //设置Lable上的进度值
                        label_Cpy_Lc.Text = "复制进程:" + Convert.ToInt32((i * 100) / WriteTimes).ToString() + "%";

                        //设置写入值
                        label_Write.Text = "已写入" + (FileToRead.Position / 1024).ToString() + "KB";
                    }

                    //剩余字节的读和写
                    if (L_Size != 0)
                    {
                        FileToRead.Read(byteToLastWrite, 0, L_Size);

                        FileToWrite.Write(byteToLastWrite, 0, L_Size);
                    }
                }
                else
                {
                    progressBar.Maximum =(int) FileToRead.Length;
                    byteToWrite = new byte[FileToRead.Length];
                    FileToRead.Read(byteToWrite, 0, (int)FileToRead.Length);
                    label_Cpy_Lc.Text = "复制进程:" + Convert.ToInt32(FileToRead.Position/FileToRead.Length*100).ToString() + "%";

                    //设置写入值
                    label_Write.Text = "已写入" + (FileToRead.Position / 1024).ToString() + "KB";
                    progressBar.Value =(int )FileToRead.Position;
                    FileToWrite.Write(byteToWrite, 0, (int)FileToRead.Length);                   
                }
                FileToRead.Flush();

                FileToWrite.Flush();

                FileToRead.Close();

                FileToWrite.Close();

                MessageBox.Show("复制完成");
            }
            catch(Exception ex)

            {
                FileToRead.Flush();

                FileToWrite.Flush();

                FileToRead.Close();

                FileToWrite.Close();

                MessageBox.Show(ex.ToString());
               
            }
        }

        private void openFileBtn_Click(object sender, EventArgs e)
        {
            OpenFile getFile = new OpenFile(Cpy);
            this.Invoke(getFile);
        }










        private void button2_Click(object sender, EventArgs e)
        {
            OpenFileDialog openFileDialog1 = new OpenFileDialog();
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                textBox1.Text = openFileDialog1.FileName;
            }
        }
        private void button3_Click(object sender, EventArgs e)
        {
            FolderBrowserDialog f = new FolderBrowserDialog();
            if (f.ShowDialog() == DialogResult.OK)
            {
                textBox2.Text = f.SelectedPath +@"\"+Path.GetFileName(textBox1.Text.Trim());
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            ApiCopyFile.DoCopy(textBox1.Text.Trim(), textBox2.Text.Trim());
        }

       
    }
    public class ApiCopyFile
    {
        private const int FO_COPY = 0x0002;
        private const int FOF_ALLOWUNDO = 0x00044;
        //显示进度条  0x00044 // 不显示一个进度对话框 0x0100 显示进度对话框单不显示进度条  0x0002显示进度条和对话框  
        private const int FOF_SILENT = 0x0002;//0x0100;  
        //  
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto, Pack = 0)]
        public struct SHFILEOPSTRUCT
        {
            public IntPtr hwnd;
            [MarshalAs(UnmanagedType.U4)]
            public int wFunc;
            public string pFrom;
            public string pTo;
            public short fFlags;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fAnyOperationsAborted;
            public IntPtr hNameMappings;
            public string lpszProgressTitle;
        }
        [DllImport("shell32.dll", CharSet = CharSet.Auto)]
        static extern int SHFileOperation(ref SHFILEOPSTRUCT FileOp);
        public static bool DoCopy(string strSource, string strTarget)
        {
            SHFILEOPSTRUCT fileop = new SHFILEOPSTRUCT();
            fileop.wFunc = FO_COPY;
            fileop.pFrom = strSource;
            fileop.lpszProgressTitle = "复制大文件";
            fileop.pTo = strTarget;
            //fileop.fFlags = FOF_ALLOWUNDO;  
            fileop.fFlags = FOF_SILENT;

            return SHFileOperation(ref fileop) == 0;
        }
    }
}