Download Manager for update Application

• Download Component_Update.zip - 40.7 KB

Introduction

As .NET Developer for implement a project that will check on some web server if there are update i use microsoft "ClickOnce".

But because this application will be run on Windows locked i prefered to use the code to make the goal.

Background

The principal component of this project are:

1. a XML file that reside on Web server
2. The Component Update
3. The client of Component update
4. The principal program

The file Xml is structured on this way:

<?xml version="1.0" encoding="utf-8" ?>
<Updates>
<update id="1" dtUpdate="2007_06_01" version="1_0_0_1" RestartFastBet="False">
<details>
<file remote="http://youWebServer/fastbet_Download/1_0_0_1/fastbet.exe" locale="fastbet.exe" MustStart="False"></file>
<config key="Last_Update" section="Update" value="2007_06_01"></config>
</details>
</update>
<update id="2" dtUpdate="2007_07_02" version="1_0_0_1" RestartFastBet="False">
<details>
<config key="Last_Update" section="Update" value="2007_07_02"></config>
</details>
</update>
</Updates>

Every TAG update is a new version of program, the date of this version is attribute dtUpdate inside update node, so if version of program (that i match with key getSetting("FastBet", "Update", "LastUpdate") is old, the first thig that i do is to download file and metadata.

The file of new version i found with attributes inside <file> node.

The attribute remote is the URI where the file must be downloaded, and locale is the path where the file must will copied on local machine.

And Metadata is represented with node <config>.

The metadata section have the same attribute use to save key on registry:

savesetting("Fastbet", "[section]","[key]", "[value]").

Below we can see how this works!

Using the code

In the component update part I use the class Update.

On this class there is a method that will get file xml and it will be loaded in XMLDoc property:

Public Sub CheckForUpdate(ByVal sUrl As String)
Dim Request As HttpWebRequest = CType(WebRequest.Create(sUrl), HttpWebRequest)
Dim response As HttpWebResponse = CType(Request.GetResponse, HttpWebResponse)
Dim responseStream As StreamReader = New StreamReader
response.GetResponseStream()
Dim output As String = responseStream.ReadToEnd()
responseStream.Close()
response.Close()
xMLdOC.LoadXml(output)
End Sub

Function Main()

Try

Dim bytesProcessed As Integer = 0

Dim remoteStream As Stream = Nothing

Dim localeStream As Stream = Nothing

Dim response As HttpWebResponse = Nothing

Dim request As HttpWebRequest = CType(WebRequest.Create(remoteFile), HttpWebRequest)

response = request.GetResponse

If Not response Is Nothing Then

remoteStream = response.GetResponseStream

localeStream = File.Create(LocaleFile)

Dim buffer(1024) As Byte

Dim Bytesread As Integer

Do

Bytesread = remoteStream.Read(buffer, 0, buffer.Length)

localeStream.Write(buffer, 0, Bytesread)

bytesProcessed += Bytesread

If Bytesread = 0 Then Exit Do

Loop

If Not response Is Nothing Then response.Close()

If Not remoteStream Is Nothing Then remoteStream.Close()

If Not localeStream Is Nothing Then localeStream.Close()

End If

Return bytesProcessed

End Function