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 = ;//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/).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 = ; i <= WriteTimes; i++)
                     {
                         //读源文件
                         FileToRead.Read(byteToWrite, , WriterByetNub);
 
                         //写数据到目标文件
                         FileToWrite.Write(byteToWrite, , WriterByetNub);
 
                         //设置进度条的值
                         progressBar.Value = Convert.ToInt32(i *  / WriteTimes);
 
                         Application.DoEvents();
 
                         //设置Lable上的进度值
                         label_Cpy_Lc.Text = "复制进程:" + Convert.ToInt32((i * ) / WriteTimes).ToString() + "%";
 
                         //设置写入值
                         label_Write.Text = "已写入" + (FileToRead.Position / ).ToString() + "KB";
                     }
 
                     //剩余字节的读和写
                     if (L_Size != )
                     {
                         FileToRead.Read(byteToLastWrite, , L_Size);
 
                         FileToWrite.Write(byteToLastWrite, , L_Size);
                     }
                 }
                 else
                 {
                     progressBar.Maximum =(int) FileToRead.Length;
                     byteToWrite = new byte[FileToRead.Length];
                     FileToRead.Read(byteToWrite, , (int)FileToRead.Length);
                     label_Cpy_Lc.Text = "复制进程:" + Convert.ToInt32(FileToRead.Position/FileToRead.Length*).ToString() + "%";
 
                     //设置写入值
                     label_Write.Text = "已写入" + (FileToRead.Position / ).ToString() + "KB";
                     progressBar.Value =(int )FileToRead.Position;
                     FileToWrite.Write(byteToWrite, , (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 = )]
         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) == ;
         }
     }
 }