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[转载]借助WebService实现多线程上传文件

原创 Linux操作系统 作者:dinner1007 时间:2019-04-15 21:15:06 0 删除 编辑
借助WebService实现多线程上传文件
借助WebService实现多线程上传文件

WebService的帮助下,进行多线程上传文件是非常简单。因此我只做个简单的例子,那么如果想要实现此功能的朋友,可以在我的基础上进行扩展。

首先说说服务器端,只需要提供一个能允许多线程写文件的函数即可,具体代码如下。

[WebMethod]

public bool UploadFileData( string FileName, int StartPosition, byte[] bData )

{

string strFullName = Server.MapPath( "Uploads" ) + @"" + FileName;

FileStream fs = null;

try

{

fs = new FileStream( strFullName, FileMode.OpenOrCreate,

FileAccess.Write, FileShare.Write );

}

catch( IOException err )

{

Session["ErrorMessage"] = err.Message;

return false;

}

using( fs )

{

fs.Position = StartPosition;

fs.Write( bData, 0, bData.Length );

}

return true;

}

其中“Uploads”是在服务程序所在目录下的一个子目录,需要设置ASPNET用户对此目录具有可写权限。

相对于服务器端来说,客户端要稍微复杂一些,因为要牵扯到多线程的问题。为了更好的传递参数,我用一个线程类来完成。具体如下。

public delegate void UploadFileData( string FileName, int StartPos, byte[] bData );

///

/// FileThread: a class for sub-thread

///

sealed class FileThread

{

private int nStartPos;

private int nTotalBytes;

private string strFileName;

public static UploadFileData UploadHandle;

///

/// Constructor

///

///

///

///

public FileThread( int StartPos, int TotalBytes, string FileName )

{

//Init thread variant

nStartPos = StartPos;

nTotalBytes = TotalBytes;

strFileName = FileName;

//Only for debug

Debug.WriteLine( string.Format( "File name:{0} position: {1} total byte:{2}",

strFileName, nStartPos, nTotalBytes ) );

}

///

/// Sub-thread entry function

///

///

public void UploadFile( object stateinfo )

{

int nRealRead, nBufferSize;

const int BUFFER_SIZE = 10240;

using( FileStream fs = new FileStream( strFileName,

FileMode.Open, FileAccess.Read,

FileShare.Read ) )

{

string sName = strFileName.Substring( strFileName.LastIndexOf( "\" ) + 1 );

byte[] bBuffer = new byte[BUFFER_SIZE];//Init 10k buffer

fs.Position = nStartPos;

nRealRead = 0;

do

{

nBufferSize = BUFFER_SIZE;

if( nRealRead + BUFFER_SIZE > nTotalBytes )

nBufferSize = nTotalBytes - nRealRead;

nBufferSize = fs.Read( bBuffer, 0, nBufferSize );

if( nBufferSize == BUFFER_SIZE )

UploadHandle( sName,

nRealRead + nStartPos,

bBuffer );

else if( nBufferSize > 0 )

{

//Copy data

byte[] bytData = new byte[nBufferSize];

Array.Copy( bBuffer,0, bytData, 0, nBufferSize );

UploadHandle( sName,

nRealRead + nStartPos,

bytData );

}

nRealRead += nBufferSize;

}

while( nRealRead < nTotalBytes );

}

//Release signal

ManualResetEvent mr = stateinfo as ManualResetEvent;

if( mr != null )

mr.Set();

}

}

那么在执行的时候,要创建线程类对象,并为每一个每个线程设置一个信号量,从而能在所有线程都结束的时候得到通知,大致的代码如下。

FileInfo fi = new FileInfo( txtFileName.Text );

if( fi.Exists )

{

btnUpload.Enabled = false;//Avoid upload twice

//Init signals

ManualResetEvent[] events = new ManualResetEvent[5];

//Devide blocks

int nTotalBytes = (int)( fi.Length / 5 );

for( int i = 0; i < 5; i++ )

{

events[i] = new ManualResetEvent( false );

FileThread thdSub = new FileThread(

i * nTotalBytes,

( fi.Length - i * nTotalBytes ) > nTotalBytes ? nTotalBytes:(int)( fi.Length - i * nTotalBytes ),

fi.FullName );

ThreadPool.QueueUserWorkItem( new WaitCallback( thdSub.UploadFile ), events[i] );

}

//Wait for threads finished

WaitHandle.WaitAll( events );

//Reset button status

btnUpload.Enabled = true;

}

总体来说,程序还是相对比较简单,而我也只是做了个简单例子而已,一些细节都没有进行处理。

本来想打包提供给大家下载,没想到CSDNBlog对于这点做的太差,老是异常。

如下是客户端的完整代码。

//--------------------------- Multi-thread Upload Demo ---------------------------------------

//--------------------------------------------------------------------------------------------

//---File: frmUpload

//---Description: The multi-thread upload form file to demenstrate howto use multi-thread to

// upload files

//---Author: Knight

//---Date: Oct.12, 2006

//--------------------------------------------------------------------------------------------

//---------------------------{Multi-thread Upload Demo}---------------------------------------

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

namespace CSUpload

{

using System.IO;

using System.Diagnostics;

using System.Threading;

using WSUploadFile;//Web-service reference namespace

///

/// Summary description for Form1.

///

public class frmUpload : System.Windows.Forms.Form

{

private System.Windows.Forms.TextBox txtFileName;

private System.Windows.Forms.Button btnBrowse;

private System.Windows.Forms.Button btnUpload;

///

/// Required designer variable.

///

private System.ComponentModel.Container components = null;

public frmUpload()

{

//

// Required for Windows Form Designer support

//

InitializeComponent();

//

// TODO: Add any constructor code after InitializeComponent call

//

}

///

/// Clean up any resources being used.

///

protected override void Dispose( bool disposing )

{

if( disposing )

{

if (components != null)

{

components.Dispose();

}

}

base.Dispose( disposing );

}

#region Windows Form Designer generated code

///

/// Required method for Designer support - do not modify

/// the contents of this method with the code editor.

///

private void InitializeComponent()

{

this.txtFileName = new System.Windows.Forms.TextBox();

this.btnBrowse = new System.Windows.Forms.Button();

this.btnUpload = new System.Windows.Forms.Button();

this.SuspendLayout();

//

// txtFileName

//

this.txtFileName.Location = new System.Drawing.Point(16, 24);

this.txtFileName.Name = "txtFileName";

this.txtFileName.Size = new System.Drawing.Size(248, 20);

this.txtFileName.TabIndex = 0;

this.txtFileName.Text = "";

//

// btnBrowse

//

this.btnBrowse.Location = new System.Drawing.Point(272, 24);

this.btnBrowse.Name = "btnBrowse";

this.btnBrowse.TabIndex = 1;

this.btnBrowse.Text = "&Browse...";

this.btnBrowse.Click += new System.EventHandler(this.btnBrowse_Click);

//

// btnUpload

//

this.btnUpload.Location = new System.Drawing.Point(272, 56);

this.btnUpload.Name = "btnUpload";

this.btnUpload.TabIndex = 2;

this.btnUpload.Text = "&Upload";

this.btnUpload.Click += new System.EventHandler(this.btnUpload_Click);

//

// frmUpload

//

this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);

this.ClientSize = new System.Drawing.Size(370, 111);

this.Controls.Add(this.btnUpload);

this.Controls.Add(this.btnBrowse);

this.Controls.Add(this.txtFileName);

this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;

this.MaximizeBox = false;

this.Name = "frmUpload";

this.Text = "Upload";

this.Load += new System.EventHandler(this.frmUpload_Load);

this.ResumeLayout(false);

}

#endregion

///

/// The main entry point for the application.

///

static void Main()

{

Application.Run(new frmUpload());

}

private FileUpload myUpload = new FileUpload();

private void UploadData( string FileName, int StartPos, byte[] bData )

{

//Call web service upload

myUpload.UploadFileData( FileName, StartPos, bData );

}

private void btnUpload_Click(object sender, System.EventArgs e)

{

FileInfo fi = new FileInfo( txtFileName.Text );

if( fi.Exists )

{

btnUpload.Enabled = false;//Avoid upload twice

//Init signals

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