C#通过FileStream复制文件

界面.jpg

运行.jpg

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

namespace CopyFileExample
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void SelectButton_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Title = "请选择要复制的文件";
            ofd.InitialDirectory = @"C:\Users\Sudo\桌面";
            ofd.Filter = "所有文件|*.*";
            ofd.ShowDialog();
            SourceFileTextBox.Text = ofd.FileName;
            
        }

        private void SaveButton_Click(object sender, EventArgs e)
        {
            SaveFileDialog sfd = new SaveFileDialog();
            sfd.Title = "请选择要保存文件路径";
            sfd.InitialDirectory = @"C:\Users\Sudo\桌面";
            sfd.Filter = "所有文件|*.*";
            sfd.ShowDialog();
            DestFileTextBox.Text = sfd.FileName;
            //先读取  再写入
            using (FileStream fsRead = new FileStream(SourceFileTextBox.Text.Trim(), FileMode.OpenOrCreate, FileAccess.Read))
            {
                using(FileStream fsWrite = new FileStream(DestFileTextBox.Text.Trim(), FileMode.OpenOrCreate, FileAccess.Write))
                {
                    //设置进度条最大值
                    SaveFileProgressBar.Maximum = (int)fsRead.Length;
                    //设置缓冲区大小
                    byte[] buffer = new byte[1024 * 1024 * 3];
                    while (true)
                    {
                        //读
                        int r = fsRead.Read(buffer, 0, buffer.Length);
                        if (r==0)
                        {
                            break;
                        }
                        //写
                        fsWrite.Write(buffer, 0, r);
                        //进度条进度值与写入数据大小关联
                        SaveFileProgressBar.Value =(int)fsWrite.Length;
                    }
                    MessageBox.Show("保存成功！");
                }
            }
        }
    }
}