Even though they're loosely related, you've presented two separate questions here.
- Why is the call failing when I use the
WebBrowser
control to load a page via HTTPS?
- Why is the call failing when I use the
DownloadFile()
method to download a file via HTTPS?
First, you need to eliminate the possibility that your code is failing. Try both of the tasks above using public HTTPS URLs that are known to work correctly.
If you discover that the source of the problem is your private URL, you may want to consider whether you want to ignore SSL errors in your WebBrowser
control.
You can do so using the (untested, translated to VB) code from this blog post:
Partial Public Class Form1
Inherits Form
Private WithEvents WebBrowser As New WebBrowser
Private Sub WebBrowser_DocumentCompleted(Sender As Object, e As WebBrowserDocumentCompletedEventArgs) Handles WebBrowser.DocumentCompleted
If e.Url.ToString() = "about:blank" Then
'create a certificate mismatch
WebBrowser.Navigate("https://74.125.225.229/")
End If
End Sub
End Class
<Guid("6D5140C1-7436-11CE-8034-00AA006009FA")>
<InterfaceType(ComInterfaceType.InterfaceIsIUnknown)>
<ComImport>
Public Interface UCOMIServiceProvider
<PreserveSig>
Function QueryService(<[In]> ByRef guidService As Guid, <[In]> ByRef riid As Guid, <Out> ByRef ppvObject As IntPtr) As <MarshalAs(UnmanagedType.I4)> Integer
End Interface
<ComImport>
<ComVisible(True)>
<Guid("79eac9d5-bafa-11ce-8c82-00aa004ba90b")>
<InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)>
Public Interface IWindowForBindingUI
<PreserveSig>
Function GetWindow(<[In]> ByRef rguidReason As Guid, <[In], Out> ByRef phwnd As IntPtr) As <MarshalAs(UnmanagedType.I4)> Integer
End Interface
<ComImport>
<ComVisible(True)>
<Guid("79eac9d7-bafa-11ce-8c82-00aa004ba90b")>
<InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)>
Public Interface IHttpSecurity
'derived from IWindowForBindingUI
<PreserveSig>
Function GetWindow(<[In]> ByRef rguidReason As Guid, <[In], Out> ByRef phwnd As IntPtr) As <MarshalAs(UnmanagedType.I4)> Integer
<PreserveSig>
Function OnSecurityProblem(<[In], MarshalAs(UnmanagedType.U4)> dwProblem As UInteger) As Integer
End Interface
Public Class MyWebBrowser
Inherits WebBrowser
Public Shared IID_IHttpSecurity As New Guid("79eac9d7-bafa-11ce-8c82-00aa004ba90b")
Public Shared IID_IWindowForBindingUI As New Guid("79eac9d5-bafa-11ce-8c82-00aa004ba90b")
Public Const S_OK As Integer = 0
Public Const S_FALSE As Integer = 1
Public Const E_NOINTERFACE As Integer = &H80004002
Public Const RPC_E_RETRY As Integer = &H80010109
Protected Overrides Function CreateWebBrowserSiteBase() As WebBrowserSiteBase
Return New MyWebBrowserSite(Me)
End Function
Private Class MyWebBrowserSite
Inherits WebBrowserSite
Implements UCOMIServiceProvider
Implements IHttpSecurity
Implements IWindowForBindingUI
Private myWebBrowser As MyWebBrowser
Public Sub New(myWebBrowser As MyWebBrowser)
MyBase.New(myWebBrowser)
Me.myWebBrowser = myWebBrowser
End Sub
Public Function QueryService(ByRef guidService As Guid, ByRef riid As Guid, ByRef ppvObject As IntPtr) As Integer Implements UCOMIServiceProvider.QueryService
If riid = IID_IHttpSecurity Then
ppvObject = Marshal.GetComInterfaceForObject(Me, GetType(IHttpSecurity))
Return S_OK
End If
If riid = IID_IWindowForBindingUI Then
ppvObject = Marshal.GetComInterfaceForObject(Me, GetType(IWindowForBindingUI))
Return S_OK
End If
ppvObject = IntPtr.Zero
Return E_NOINTERFACE
End Function
Public Function GetWindow(ByRef rguidReason As Guid, ByRef phwnd As IntPtr) As Integer Implements IHttpSecurity.GetWindow, IWindowForBindingUI.GetWindow
If rguidReason = IID_IHttpSecurity OrElse rguidReason = IID_IWindowForBindingUI Then
phwnd = myWebBrowser.Handle
Return S_OK
Else
phwnd = IntPtr.Zero
Return S_FALSE
End If
End Function
Public Function OnSecurityProblem(dwProblem As UInteger) As Integer Implements IHttpSecurity.OnSecurityProblem
'ignore errors
'undocumented return code, does not work on IE6
Return S_OK
End Function
End Class
End Class
Regarding problem #2: It appears you may be confusing WebBrowser
and DownloadFile()
. As you've probably already discovered, the WebBrowser
control doesn't download files. However, you can simulate the behavior using this technique:
Partial Public Class Form2
Inherits Form
Private Sub WebBrowser_Navigating(Sender As Object, e As WebBrowserNavigatingEventArgs) Handles WebBrowser.Navigating
Dim sFilePath As String
Dim oClient As Net.WebClient
' This can be any conditional criteria you wish '
If (e.Url.Segments(e.Url.Segments.Length - 1).EndsWith(".pdf")) Then
SaveFileDialog.FileName = e.Url.Segments(e.Url.Segments.Length - 1)
e.Cancel = True
If SaveFileDialog.ShowDialog() = DialogResult.OK Then
sFilePath = SaveFileDialog.FileName
oClient = New Net.WebClient
AddHandler oClient.DownloadFileCompleted, New AsyncCompletedEventHandler(AddressOf DownloadFileCompleted)
oClient.DownloadFileAsync(e.Url, sFilePath)
End If
End If
End Sub
Private Sub DownloadFileCompleted(Sender As Object, e As AsyncCompletedEventArgs)
MessageBox.Show("File downloaded")
End Sub
Private WithEvents SaveFileDialog As New SaveFileDialog
Private WithEvents WebBrowser As New WebBrowser
End Class
In any event, the first step in solving this is to figure out whether it's your code or the private URL that's causing your issue.