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我最近要写一个供有相关权限的管理人员查询大额资金明细的程序，界面如下：
所需的数据文件是放在报表服务器上，每天一个压缩文件，该压缩文件中除了所需的储蓄流水账文件外，还有很多其他的文件。如果先把该压缩文件从报表服务器下载到应用服务器上，再进行解压缩处理的话，一是多下载了该压缩文件中我们不需要的其他文件，二是还必须在应用服务器上建立以SessionID等方法标识的临时文件，以免其他用户也在进行查询时文件名冲突，三是使用完毕后还必须删除该临时文件。
我的处理方法是如下：
using (ZipInputStream zs = Zip.GetZipInputStream((new FtpClient(Pub.Ftp1Uri, Pub.Ftp1User, Pub.Ftp1Pswd)).
GetDownloadStream(Path.Combine(Pub.Ftp1EPath, zipFileName)), binFileName, out size))
{
if (size % Pub.P_R2 != 0) throw new ApplicationException("文件长度错: " + binFileName);
byte [] bs = new byte[Pub.P_R2];
long recs = size / Pub.P_R2;
for (long rec = 0; rec < recs; rec++)
{
Zip.ReadStream(zs, bs);
...
}
首先，用 FtpClient.GetDownloadStream() 方法得到一个对应于FTP服务器上文件的Stream，然后把这个Stream传给Zip.GetZipInputStream()方法，得到一个ZipInputStream，然后使用Zip.ReadStream()方法一行一行读取储蓄流水账文件到byte[]中去，这样就取得了我们所需的数据，就象储蓄流水账文件就存放在本地硬盘上一样，避免了下载文件和解压文件。具体代码如下：
using System; using System.IO; using System.Net; namespace Skyiv.Util 
{ 
sealed class FtpClient 
{ Uri uri; string userName; string password; public FtpClient(string uri, string userName, string password) { this.uri = new Uri(uri); this.userName = userName; this.password = password; 
} public Stream GetDownloadStream(string sourceFile) { Uri downloadUri = new Uri(uri, sourceFile); if (downloadUri.Scheme != Uri.UriSchemeFtp) throw new ArgumentException("URI is not an FTP site"); FtpWebRequest ftpRequest = (FtpWebRequest)WebRequest.Create(downloadUri); ftpRequest.Credentials = new NetworkCredential(userName, password); ftpRequest.Method = WebRequestMethods.Ftp.DownloadFile; return ((FtpWebResponse)ftpRequest.GetResponse()).GetResponseStream(); } /*public */void Download(string sourceFile, string destinationFile) { using (Stream reader = GetDownloadStream(sourceFile)) { using (BinaryWriter bw = new BinaryWriter(new FileStream(destinationFile, FileMode.Create))) { for (;;) { int c = reader.ReadByte(); if (c == -1) break; bw.Write((byte)c); } } } } } 
} using System; using System.IO; using ICSharpCode.SharpZipLib.Zip; namespace Skyiv.Util { static class Zip { public static void ReadStream(Stream inStream, byte [] bs) { int offset = 0; int count = bs.Length; do { int size = inStream.Read(bs, offset, count); if (size <= 0) break; offset += size; count -= size; } while (count > 0); if (count != 0) throw new ApplicationException("Zip.ReadStream(): 读输入流错"); } public static ZipInputStream GetZipInputStream(string zipFileName, string fileName, out long fileLength) { return GetZipInputStream(File.OpenRead(zipFileName), fileName, out fileLength); } public static ZipInputStream GetZipInputStream(Stream zipStream, string fileName, out long fileLength) { ZipInputStream zs = new ZipInputStream(zipStream); ZipEntry theEntry; while ((theEntry = zs.GetNextEntry()) != null) { if (Path.GetFileName(theEntry.Name) != fileName) continue; fileLength = theEntry.Size; return zs; } fileLength = -1; return null; } /*public */static void UnzipFile(string zipFile, string baseStr, params string [] fileList) { UnzipFile(File.OpenRead(zipFile), baseStr, fileList); } /*public */static void UnzipFile(Stream zipStream, string baseStr, params string [] fileList) { using (ZipInputStream zs = new ZipInputStream(zipStream)) { ZipEntry theEntry; byte[] data = new byte[4096]; while ((theEntry = zs.GetNextEntry()) != null) { if (Array.IndexOf(fileList, Path.GetFileName(theEntry.Name)) < 0) continue; using (FileStream sw = new FileStream(baseStr+Path.GetFileName(theEntry.Name), FileMode.Create)) { while (true) { int size = zs.Read(data, 0, data.Length); if (size <= 0) break; sw.Write(data, 0, size); } } } } } } } void MakeData(DateTime workDate, short brno, short currtype, decimal startAmt) { Pub.SetNOVA(workDate); string zipFileName = string.Format("e-{0:yyyyMMdd}-{1:D4}-0000{2}.zip", workDate, Pub.Zone, Pub.IsNOVAv12 ? "-2" : ""); string binFileName = string.Format("e-{0:yyyyMMdd}-pfsjnl.bin", workDate); long size; DataTable dt = MakeDataTable(); using (ZipInputStream zs = Zip.GetZipInputStream((new FtpClient(Pub.Ftp1Uri, Pub.Ftp1User, Pub.Ftp1Pswd)). GetDownloadStream(Path.Combine(Pub.Ftp1EPath, zipFileName)), binFileName, out size)) { if (size % Pub.P_R2 != 0) throw new ApplicationException("文件长度错: " + binFileName); byte [] bs = new byte[Pub.P_R2]; long recs = size / Pub.P_R2; for (long rec = 0; rec < recs; rec++) { Zip.ReadStream(zs, bs); if (Etc.Encode.GetString(bs,Pub.P_R2_RevTran,Pub.L_Revtran) != "0") continue; // 反交易标志 for (int i = 0; i < 2; i++) { bool isDebit = (i == 0); if (int.Parse(Etc.Encode.GetString(bs,(isDebit?Pub.P_R2_Drcurr:Pub.P_R2_Crcurr),Pub.L_Curr)) != currtype) continue; decimal amt0 = decimal.Parse(Etc.Encode.GetString(bs,(isDebit?Pub.P_R2_Amount1:Pub.P_R2_Amount2),Pub.L_Bal)) / 100; if (Math.Abs(amt0) < startAmt) continue; string account = Etc.Encode.GetString(bs,(isDebit?Pub.P_R2_Draccno:Pub.P_R2_Craccno),Pub.L_Accno); if (!DbBranch.IsMyAccount(account, brno)) continue; string customer = Etc.Encode.GetString(bs,Pub.P_R2_Notes1,Pub.L_Notes1).Trim(‘@‘, ‘ ‘); short nodeno = short.Parse(Etc.Encode.GetString(bs,Pub.P_R2_Brno,Pub.L_Brno)); int code = int.Parse(Etc.Encode.GetString(bs,Pub.P_R2_Trxcode,Pub.L_Trxcode)); DataRow dr = dt.NewRow(); dr["No"] = nodeno; dr["Name"] = DbBranch.GetBrief(DbBranch.IsAllNode(brno), nodeno); dr["Teller"] = int.Parse(Etc.Encode.GetString(bs,Pub.P_R2_Teller,Pub.L_Teller)); dr["Account"] = IcbcEtc.FormatAccount19(account); dr["User"] = customer; dr["Flag"] = (isDebit ? "借" : "贷"); dr["Amt"] = amt0; dr["Memo"] = Etc.Encode.GetString(bs,Pub.P_R2_Cashnote,Pub.L_Cashnote); dr["Code"] = code; dr["TrName"] = DbTrxCode.GetNewName(code); dt.Rows.Add(dr); } } } DataView dv = dt.DefaultView; dv.Sort = "Flag DESC, Amt DESC"; dgMain.DataSource = dv; dgMain.DataBind(); } 版权声明：本文为博主http://www.zuiniusn.com 原创文章，未经博主允许不得转载。
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原文地址：http://blog.csdn.net/u013141940/article/details/47163965
