如何将 DownloadFileAsync 添加到 vb.net 中的更新程序
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How to add DownloadFileAsync to updater program in vb.net
提问by TheCreepySheep
I'm making a automatic file downloader and I need it to redownload and overwrite the file, when i press the button, but i don't want it to hang when it is downloading. I don't know how to implement DownloadFileAsync to this code. Please help!
我正在制作一个自动文件下载器，当我按下按钮时，我需要它来重新下载和覆盖文件，但我不希望它在下载时挂起。我不知道如何对这段代码实现 DownloadFileAsync。请帮忙！
Here is my code:
这是我的代码：
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Button1.Enabled = False
Button1.Text = "Updating..."
WebBrowser1.Visible = True
My.Computer.Network.DownloadFile _
(address:="http://199.91.154.170/e9f6poiwfocg/pei02c8727sa720/Ultra+v08.zip", _
destinationFileName:=Path.Combine(Environment.GetFolderPath( _
Environment.SpecialFolder.ApplicationData), _
"test/Test.zip"), _
userName:=String.Empty, password:=String.Empty, _
showUI:=False, connectionTimeout:=100000, _
overwrite:=True)
WebBrowser1.Visible = False
Button1.Text = "Updated!"
PictureBox1.Visible = True
End Sub
Thanks in advance!
提前致谢！
采纳答案by Parimal Raj
You can use the System.Net.WebClientto download a file in async mode.
您可以使用System.Net.WebClient以异步模式下载文件。
Sample Code :
示例代码：
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim client As New WebClient()
AddHandler client.DownloadProgressChanged, AddressOf ShowDownloadProgress
AddHandler client.DownloadFileCompleted, AddressOf OnDownloadComplete
client.DownloadFileAsync(New Uri("http://199.91.154.170/e9f6poiwfocg/pei02c8727sa720/Ultra v08.zip"), "test/Test.zip")
End Sub
Private Sub OnDownloadComplete(ByVal sender As Object, ByVal e As AsyncCompletedEventArgs)
If Not e.Cancelled AndAlso e.Error Is Nothing Then
MessageBox.Show("DOwnload success")
Else
MessageBox.Show("Download failed")
End If
End Sub
Private Sub ShowDownloadProgress(ByVal sender As Object, ByVal e As DownloadProgressChangedEventArgs)
ProgressBar1.Value = e.ProgressPercentage
End Sub
