Imports System.IO
Imports System.Net
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Public Class Form1Class Form1
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Private Sub Button1_Click()Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Me.Button1.Text = "正在连接远程服务器
"
Me.Button1.Refresh()
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'If My.Computer.Network.Ping("192.168.3.33", 3000) = False Then
' Me.Button1.Text = "连接远程服务器失败!"
' Return
'End If
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Dim fileName As String = Nothing
Dim url As String = Nothing
fileName = "d:\\mydownTest.exe"
url = "http://localhost:2127/DownTest/Default.aspx?id=FJ2007.4.25.1"
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'下载文件
Dim startP As Decimal = 0
Dim fs As IO.FileStream = Nothing
If IO.File.Exists(fileName) Then
fs = IO.File.OpenWrite(fileName) '打开上次下载的文件
startP = fs.Length
fs.Seek(startP, SeekOrigin.Current) '移动文件流中的当前指针
Else
fs = New IO.FileStream(fileName, IO.FileMode.Create) '新建下载文件
startP = 0
End If
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Try
Me.Button1.Text = "正在下载升级文件
"
Me.Button1.Refresh()
Dim request As Net.HttpWebRequest = Net.HttpWebRequest.Create(url) '向服务器请求,获得服务器回应数据流
If startP > 0 Then
request.AddRange(startP) '设置Range值
End If
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Dim ns As IO.Stream = request.GetResponse().GetResponseStream()
Dim byt(512) As Byte
Dim readSize As Integer = 0
readSize = ns.Read(byt, 0, 512)
While readSize > 0
'先检查磁盘剩余空间
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fs.Write(byt, 0, readSize)
readSize = ns.Read(byt, 0, 512)
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End While
ns.Close()
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Me.Button1.Text = "下载完成"
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Catch ex As Exception
Throw ex
Finally
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fs.Close()
System.Diagnostics.Process.Start(fileName)
Me.Close()
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End Try
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End Sub
End Class
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posted @
2007-04-25 21:16
yongwnet
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