C# 黑马.Net_大文件拷贝实例源码

大文件拷贝实例源码，学习关于IO文件流、多线程相关使用做参考。 private void button4_Click(object sender, EventArgs e) { this.progressBar1.Value = 0; this.label1.Text = "0%"; if (!File.Exists(this.textBox1.Text)) { MessageBox.Show("找不到目标文件！"); return; } if (!Directory.Exists(this.textBox2.Text)) { MessageBox.Show("请选择有效的保存路径！"); return; } string fileRead = this.textBox1.Text; string fileSave = Path.Combine(this.textBox2.Text, _fileName); System.Threading.ThreadPool.QueueUserWorkItem((o) => { using (IDisposable file = new FileStream(fileRead, FileMode.Open, FileAccess.Read), fileWrite = new FileStream(fileSave, FileMode.Create, FileAccess.Write)) { int count = 0; long fileLength =((FileStream)file).Length; //目标文件大小 //根据目标文件大小创建byte数组长度 byte[] data = new byte[fileLength > 1024 * 1024 * 30 ? 1024 * 1024 * 30 : fileLength]; //30M 1024 * 1024 * 30 int step = (int)Math.Ceiling(fileLength * 1.0 / data.Length); //分流段数 double n = (100 * 1.0 / step); //每次进度条累加 double m = 0; //累加统计 int spam = 1; //时间间隔 double speed = 0; //拷贝速度 do { DateTime time = DateTime.Now; //文件流操作 count = ((FileStream)file).Read(data, 0, data.Length); ((FileStream)fileWrite).Write(data, 0, count); //保存时间间隔，单位毫秒 spam = (DateTime.Now - time).Milliseconds > 0 ? (DateTime.Now - time).Milliseconds : spam;//必须大于0 //计算速度 单位k/s if (count == data.Length) { speed = (count * 1.0 / 1024 / spam) * 1000; } //进度条 m = m + n; //控件显示 ShowProbar(o, m, speed); } while (count > 0); } if (this.progressBar1.Value == 100) { System.Threading.Thread.Sleep(1000); //延迟1秒弹出 MessageBox.Show("拷贝成功！"); } }); }