ASP.NET 在线压缩与解压文件

压缩与解压函数

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;
using System.IO.Compression;

/// <summary>
///ComPress 的摘要说明
/// </summary>
public class ComPress
{
	public ComPress()
	{
		
	}

    /// <summary>
    /// 压缩文件
    /// </summary>
    /// <param name="sourceFile">原文件</param>
    /// <param name="destinationFile">目标文件</param>
    public static void ComPressFile(string sourceFile, string destinationFile)
    {
        if (!File.Exists(sourceFile))
        {
            throw new FileNotFoundException();
        }
        using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite))
        {
            byte[] buffer = new byte[sourceStream.Length];
            int checkCounter = sourceStream.Read(buffer, 0, buffer.Length);
            if (checkCounter != buffer.Length)
            {
                throw new ApplicationException();
            }
            using (FileStream destinationStream = new FileStream(destinationFile, FileMode.OpenOrCreate, FileAccess.Write))
            {
                using (GZipStream compressStream = new GZipStream(destinationStream, CompressionMode.Compress, true))
                {
                    compressStream.Write(buffer, 0, buffer.Length);
                }
            }
        }
    }

    /// <summary>
    /// 解缩文件
    /// </summary>
    /// <param name="sourceFile">原文件</param>
    /// <param name="destinationFile">目标文件</param>
    public static void DeCompress(string sourceFile, string destinationFile)
    {
        if (!File.Exists(sourceFile))
        {
            throw new FileNotFoundException();
        }
        using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open))
        {
            byte[] quartetBuffer = new byte[4];
            int position = (int)sourceStream.Length - 4;
            sourceStream.Position = position;
            sourceStream.Read(quartetBuffer, 0, 4);
            sourceStream.Position = 0;
            int checkLength = BitConverter.ToInt32(quartetBuffer, 0);
            byte[] buffer = new byte[checkLength + 100];
            using (GZipStream deCompressedStream = new GZipStream(sourceStream, CompressionMode.Decompress, true))
            {
                int total = 0;
                for (int offset = 0; ; )
                {
                    int bytesRead = deCompressedStream.Read(buffer, offset, 100);
                    if (bytesRead == 0)
                        break;
                    offset += bytesRead;
                    total += bytesRead;
                }
                using (FileStream destinationStream = new FileStream(destinationFile, FileMode.Create))
                {
                    destinationStream.Write(buffer, 0, total);
                    destinationStream.Flush();
                }
            }
        }
    }

}

页面代码

<form id="form1" runat="server">
    <div>
    要压缩文件：<asp:DropDownList ID="ddlFile" runat="server"></asp:DropDownList>
    <asp:Button ID="btnCompress" runat="server" onclick="btnCompress_Click" Text="压缩" />
    <asp:Button ID="btnDeCompress" runat="server" o Text="解压" 
            onclick="btnDeCompress_Click" />
    </div>
    </form>

后台代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;

public partial class Compress : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string path = Server.MapPath(".");
            DirectoryInfo dir = new DirectoryInfo(path);
            foreach (FileInfo fileName in dir.GetFiles())
            {
                ddlFile.Items.Add(new ListItem(fileName.Name, fileName.Name));
            }
        }
    }
    protected void btnCompress_Click(object sender, EventArgs e)
    {
        try
        {
            ComPress.ComPressFile(Server.MapPath("./") + ddlFile.Text, Server.MapPath("./")+"asd.rar");
            Page.ClientScript.RegisterStartupScript(Page.GetType(), "mess", "<script language='javascript' defer>alert('压缩成功');</script>");
        }
        catch
        {
            Page.ClientScript.RegisterStartupScript(Page.GetType(), "mess", "<script language='javascript' defer>alert('压缩失败');</script>");
        }
    }
    protected void btnDeCompress_Click(object sender, EventArgs e)
    {
        try
        {
            ComPress.DeCompress(Server.MapPath("./") + ddlFile.Text, Server.MapPath("./") + "3.txt");
            Page.ClientScript.RegisterStartupScript(Page.GetType(), "mess", "<script language='javascript' defer>alert('解压成功');</script>");
        }
        catch
        {
            Page.ClientScript.RegisterStartupScript(Page.GetType(), "mess", "<script language='javascript' defer>alert('解压失败');</script>");
        }
    }
}

本程序不足之处就是不压缩文件中的文件名不能自动的为原来的文件名。