IO Operation – continue
1.读写压缩文件
首先构造FileStream
FileStream stream =
new FileStream(filename, FileMode.Create, FileAccess.Write);
然后构造GZipStream
GZipStream compressedStream =
new GZipStream(stream, CompressionMode.Compress);
最后StreamReader
StreamWriter writer = new StreamWriter(compressedStream);
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.IO.Compression;
namespace IOTest
{
class Program
{
static void SaveCompressedFile (string filename, string data)
{
FileStream stream =
new FileStream(filename, FileMode.Create, FileAccess.Write);
GZipStream compressedStream =
new GZipStream(stream, CompressionMode.Compress);
StreamWriter writer = new StreamWriter(compressedStream);
writer.Write(data);
writer.Close();
}
static string LoadCompressedFile (string filename)
{
FileStream stream =
new FileStream(filename, FileMode.Open, FileAccess.Read);
GZipStream compressedStream =
new GZipStream(stream, CompressionMode.Decompress);
StreamReader reader = new StreamReader(compressedStream);
string data = reader.ReadToEnd();
reader.Close();
return data;
}
static void Main(string[] args)
{
try
{
string toCompressedString = "Hello World";
SaveCompressedFile("LoadCompressedFile.zip", toCompressedString);
// read the compressed data
string readString = LoadCompressedFile("LoadCompressedFile.zip");
Console.Write(readString);
}
catch (IOException ex)
{
Console.Write(ex.ToString());
}
Console.ReadKey();
}
}
}
2.串行化数据
首先需要引入System.Runtime.Serialization和System.Runtime.Serialization.Formatters.Binary，然后 IFormatter serializer = new BinaryFormatter(); 生成BinaryFormatter对象，最后使用Deserialize或者是Serialize来串行化
using System;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters;
namespace IOTest
{
[Serializable]
public class Product
{
public long id;
public string name;
public double price;
[NonSerialized]
string notes;
public Product (long i, string n, double p, string no)
{
id = i;
name = n;
price = p;
notes = no;
}
public override string ToString()
{
return string.Format("{0} : {1} (${2:F2}) {3}", id, name, price, notes);
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.IO.Compression;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
namespace IOTest
{
class Program
{
static void Main(string[] args)
{
Product product = new Product (1, "Pen", 1.0, "Good");
IFormatter serializer = new BinaryFormatter();
FileStream stream = new FileStream("Product.bin", FileMode.Create, FileAccess.Write);
serializer.Serialize(stream, product);
// read
FileStream load = new FileStream("Product.bin", FileMode.Open, FileAccess.Read);
Product pro = serializer.Deserialize(load) as Product;
Console.WriteLine(pro);
Console.ReadKey();
}
}
}
3.FileSystemWatcher
使用FileSystemWatcher非常简单，首先设置FileSystemWatcher属性
| 属性 | 说明 |
| Path | 要监控的文件的位置或者是目录 |
| NotifierFilter | 定义FileSystemWatcher需要监控哪些内容 |
| Filter | 文件过滤器 |
设置完这四个属性之后，就需要为四个时间Changed，Created，Deleted，Renamed来编写事件处理函数，这样如果某个事件发生的话，会调用相应的事件处理程序，设置完属性和事件之后，将EnableRaisingEvents设置成true，这样开始监听
#region Using directive
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
#endregion
namespace FileWatcher
{
public partial class Form1 : Form
{
private FileSystemWatcher watcher;
private delegate void UpdateWatchTextDelegate(string newText);
public Form1()
{
InitializeComponent();
this.watcher = new FileSystemWatcher();
this.watcher.Deleted +=
new FileSystemEventHandler(this.OnDeleted);
this.watcher.Renamed +=
new RenamedEventHandler(this.OnRenamed);
this.watcher.Changed +=
new FileSystemEventHandler(this.OnChanged);
this.watcher.Created +=
new FileSystemEventHandler(this.OnCreated);
}
public void UpdateWatchText (string text)
{
this.lblWatch.Text = text;
}
// define the event handler
public void OnChanged (object source, FileSystemEventArgs args)
{
try
{
FileStream stream = new FileStream(@"log.txt", FileMode.Append);
StreamWriter writer = new StreamWriter(stream);
writer.Write("File : {0} {1}", args.FullPath, args.ChangeType.ToString());
writer.Close();
this.BeginInvoke(new UpdateWatchTextDelegate (UpdateWatchText),
"Wrote change events to log");
}
catch (IOException ex)
{
this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),
"Wrote change events to log error");
}
}
public void OnRenamed(object source, RenamedEventArgs args)
{
try
{
FileStream stream = new FileStream("log.txt", FileMode.Append, FileAccess.Write);
StreamWriter writer = new StreamWriter(stream);
writer.WriteLine("File renamed form {0} to {1}",
args.OldName, args.FullPath);
writer.Close();
this.BeginInvoke(new UpdateWatchTextDelegate (UpdateWatchText),
"Wrote renamed event to log");
}
catch (IOException ex)
{
this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),
"Wrote renamed event to log error");
}
}
public void OnDeleted (object source, FileSystemEventArgs args)
{
try
{
FileStream stream = new FileStream("log.txt", FileMode.Append, FileAccess.Write);
StreamWriter writer = new StreamWriter(stream);
writer.WriteLine("File : {0} deleted",
args.FullPath);
writer.Close();
this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),
"Wrote delete event to log");
}
catch (IOException ex)
{
this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),
"Wrote delete event to log error");
}
}
public void OnCreated(object source, FileSystemEventArgs args)
{
try
{
FileStream stream = new FileStream("log.txt", FileMode.Append, FileAccess.Write);
StreamWriter writer = new StreamWriter(stream);
writer.WriteLine("File : {0} create",
args.FullPath);
writer.Close();
this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),
"Wrote create event to log");
}
catch (IOException ex)
{
this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),
"Wrote create event to log error");
}
}
private void cmdBrowse_Click(object sender, EventArgs e)
{
if (FileDialog.ShowDialog () != DialogResult.Cancel)
{
txtLocation.Text = FileDialog.FileName;
cmdWatch.Enabled = true;
}
}
private void cmdWatch_Click(object sender, EventArgs e)
{
watcher.Path = Path.GetDirectoryName(txtLocation.Text);
watcher.Filter = Path.GetFileName(txtLocation.Text);
watcher.NotifyFilter = NotifyFilters.LastWrite |
NotifyFilters.FileName | NotifyFilters.Size;
lblWatch.Text = "Watch " + txtLocation.Text;
// begin watch
watcher.EnableRaisingEvents = true;
}
}
}
