用HttpWebRequest 下載檔案 - 伊莉討論區

Sub Loading(ByRef MyWeb As WebBrowser)
Do Until WebBrowserRead.ReadyState = WebBrowserReadyState.Complete
Application.DoEvents()
Loop
End Sub
Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
Dim url As Uri = New Uri("https://www.google.com.tw/search?safe=off&hl=zh-TW&site=imghp&tbm=isch&source=hp&q=" & TextBox1.Text)
Dim objWebClient As New WebClient
Dim temp As Integer
Dim DataLinkStr(1), DataLinkStr2(1) As String
Dim GetStrAllLen, Str1, Str2 As Integer
'載入網頁
WebBrowserRead.Navigate(url)
Loading(WebBrowserRead)
For Each [HtmlElement] As HtmlElement In WebBrowserRead.Document.All
If [HtmlElement].TagName = "A" And [HtmlElement].GetAttribute("href") <> Nothing Then
DataLinkStr = Split([HtmlElement].OuterHtml, "imgurl=")
If DataLinkStr.Length > 1 Then
DataLinkStr2 = Split(DataLinkStr(1), "&") '分割
RichTextBox1.Text &= DataLinkStr2(0) & vbCrLf
Str1 = InStrRev(DataLinkStr2(0), "/") '取得某字串位置
Str1 = Str1 + 1 '往後推一字元
GetStrAllLen = DataLinkStr2(0).Length '取得總字數（包涵http://)
Str2 = GetStrAllLen - Str1
If Strings.Right(DataLinkStr2(0), 4) = ".jpg" Or Strings.Right(DataLinkStr2(0), 4) = ".png" Then
ListBox1.Items.Add(Strings.Mid(DataLinkStr2(0), Str1, Str2 + 1)) '取出要存的檔名
Try
HttpWebDownload(DataLinkStr2(0))
Download_Count += 1
Catch ex As WebException
End Try
Else
Dim str3split() As String
Dim str3 As String
str3split = Split(DataLinkStr2(0), ".jpg")
str3 = str3split(0) & ".jpg"
temp += 1
End If
'objWebClient.DownloadFileAsync(New Uri(DataLinkStr2(0)), "G:\test\1\" & Strings.Mid(DataLinkStr2(0), Str1, Str2 + 1))
End If
End If
Next
End Sub
Private Download_Count As Integer
Private Download_C_temp As Integer
Private Function HttpWebDownload(ByVal InputUrl As String)
Dim bytes_ As Integer = 0
Dim MyResponse As HttpWebResponse
Dim MyRequest As HttpWebRequest
Dim RemoteStream As Stream
Dim MyFilewStream As Stream
Dim TimeStart As DateTime = Now
Dim TS As TimeSpan
MyRequest = HttpWebRequest.Create(InputUrl)
If MyRequest IsNot Nothing Then
'MyResponse.GetResponseStream()
MyRequest.Timeout = (5 * 1000)
MyResponse = MyRequest.GetResponse
If MyResponse IsNot Nothing Then
'判斷網頁狀態
If MyResponse.StatusCode = HttpStatusCode.OK Then
RemoteStream = MyResponse.GetResponseStream
MyFilewStream = File.Create("G:\temp\1\" & Download_Count & ".jpg") '檔名
Dim buffer(1024) As Byte
Dim bytesRead As Integer
TimeStart = Now
Do
bytesRead = RemoteStream.Read(buffer, 0, buffer.Length)
MyFilewStream.Write(buffer, 0, bytesRead)
bytes_ += bytesRead
Application.DoEvents()
'判斷執行時間
TS = Now.Subtract(TimeStart)
Console.WriteLine(TS)
If TS.TotalSeconds > 7 Then
Exit Do
End If
Loop While bytesRead > 0
End If
End If
End If
If MyResponse IsNot Nothing Then MyResponse.Close()
If RemoteStream IsNot Nothing Then RemoteStream.Close()
If MyFilewStream IsNot Nothing Then MyFilewStream.Close()
Return bytes_
End Function

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