[英]Capturing Javascript Alert in Internet Explorer using VB.Net
I found a similar thread here but answer is not shared by the inquirer. 我在这里找到了一个类似的帖子,但询问者不会回答这个问题。
I'm using SHDocVw.InternetExplorer APIs in my Vb.Net WinForms application to record user actions from Internet Explorer in my application. 我在我的Vb.Net WinForms应用程序中使用SHDocVw.InternetExplorer API来记录我的应用程序中来自Internet Explorer的用户操作。
I don't want to inject any javascript. 我不想注入任何JavaScript。 Is there any way by which I can directly know about the alert opening and some way of hooking it to get its text?
有什么方法可以让我直接了解警报开放以及某种方式来获取它的文本吗?
EDIT 1: 编辑1:
WindowStateChanged event is fired when a javascript alert is opened in Internet Explorer but this event is fired in many other cases also such as opening of modal dialog window, minimize Internet Explorer etc.. 在Internet Explorer中打开javascript警报时会触发WindowStateChanged事件,但在许多其他情况下也会触发此事件,例如打开模式对话框窗口,最小化Internet Explorer等。
With below code you can auto close JavaScript alert windows, get message text or send click message to buttons on alert window. 使用以下代码,您可以自动关闭JavaScript警报窗口,获取消息文本或向警报窗口上的按钮发送单击消息。
WindowStateChanged event does not fire on JavaScript alert show (on my environment). WindowStateChanged事件不会在JavaScript警报show(在我的环境中)上触发。 if it fires, below code can be used.
如果它触发,可以使用下面的代码。
<DllImport("user32.dll", SetLastError:=True)> _
Private Shared Function GetForegroundWindow() As IntPtr
End Function
Private Sub aaxWebBrowser1_WindowStateChanged(sender As Object, e As AxSHDocVw.DWebBrowserEvents2_WindowStateChangedEvent)
HandleJavascriptAlertwindows(GetForegroundWindow(), False)
End Sub
or you can use ForeGroundWindowWatcher class to catch JavaScript alert windows. 或者您可以使用ForeGroundWindowWatcher类来捕获JavaScript警报窗口。 if AxWebbrowser on a form you should change Me.ParentForm.Handle to Me.Handle
如果表单上有AxWebbrowser,则应将Me.ParentForm.Handle更改为Me.Handle
Private ForeGroundWindowWatcher_ As ForeGroundWindowWatcher
Private Sub StartForeGroundWatcher()
ForeGroundWindowWatcher_ = New ForeGroundWindowWatcher
AddHandler ForeGroundWindowWatcher_.ForegroundWindowHasChanged, AddressOf ForeGroundWindowWatcher_ForegroundWindowHasChanged
ForeGroundWindowWatcher_.Startt()
End Sub
Private Sub StopForeGroundWatcher()
If ForeGroundWindowWatcher_ IsNot Nothing Then
RemoveHandler ForeGroundWindowWatcher_.ForegroundWindowHasChanged, AddressOf ForeGroundWindowWatcher_ForegroundWindowHasChanged
ForeGroundWindowWatcher_.Stopp()
End If
End Sub
Private Sub btnStartForeGroundWatcher_Click(sender As System.Object, e As System.EventArgs) Handles btnStartForeGroundWatcher.Click
'Should be called inside form_load event
StartForeGroundWatcher()
End Sub
Private Sub btnStopForeGroundWatcher_Click(sender As System.Object, e As System.EventArgs) Handles btnStopForeGroundWatcher.Click
'Should be called inside form_Closing event
StopForeGroundWatcher()
End Sub
Private Sub ForeGroundWindowWatcher_ForegroundWindowHasChanged(sender As Object, ForeGroundWindowHandle As IntPtr)
HandleJavascriptAlertwindows(ForeGroundWindowHandle, False)
End Sub
Private LastForeGroundWindowHandle As IntPtr = IntPtr.Zero
Private Sub HandleJavascriptAlertwindows(ForeGroundWindowHandle As IntPtr, preventFromShowing As Boolean)
Try
'source http://www.vbforums.com/showthread.php?761005-WebBrowser-Control-how-to-handle-Javascript-generated-alert-window-%28onbeforeunload%29
'Dim hwnd = FindWindow("#32770", "Windows Internet Explorer")' this finds windows from its title.
Dim hwnd = ForeGroundWindowHandle 'GetForegroundWindow() 'get the foreground window
If hwnd = IntPtr.Zero Then Return
'Get forgroundwindow cvlassname. Classname of JavaScript alert windows is "#32770"
Dim ForeGroundWindowClassName As String = ForeGroundWindowHelper.GetClassNameFromHandle(hwnd)
Dim MeHandle As IntPtr = Me.ParentForm.Handle 'use Me.Handle if ME is a form.
'Debug.WriteLine(WindowClassName)
Dim AlertMessage As String = ""
Debug.WriteLine("ForeGroundWindowHandle: " + ForeGroundWindowHandle.ToString)
Debug.WriteLine("MeHandle: " + MeHandle.ToString)
Debug.WriteLine("ForeGroundWindowClassName: " + ForeGroundWindowClassName)
If String.CompareOrdinal("#32770", ForeGroundWindowClassName) = 0 Then
If LastForeGroundWindowHandle <> IntPtr.Zero AndAlso LastForeGroundWindowHandle <> MeHandle Then
'Alert might be shown another webbrowser.
Return
End If
For Each ch As ForeGroundWindowHelper.WindowChildInfo In ForeGroundWindowHelper.GetChildWindows(hwnd)
Debug.WriteLine("Text: " + ch.Text)
Debug.WriteLine("ClassName: " + ch.ClassName)
If ch.ClassName.ToLower = "static" Then
AlertMessage = ch.Text
End If
If preventFromShowing Then
'close alert by sending ESC
SendKeys.Send("{ESC}")
'or
''send click event to specific button
'If ch.ClassName = "Button" AndAlso ch.Text = "OK" Then
' ForeGroundWindowHelper.SendClickEvet2Button(ch.hWnd)
' Exit For
'End If
End If
Next
End If
Debug.WriteLine("AlertMessage: " + AlertMessage)
LastForeGroundWindowHandle = ForeGroundWindowHandle
Catch ex As Exception
Debug.WriteLine(ex.Message)
End Try
End Sub
original source Detect active window changed using C# without polling 原始源检测活动窗口使用C#更改而不进行轮询
Imports System.Runtime.InteropServices
Imports System.Text
Public Class ForeGroundWindowWatcher
'original source https://stackoverflow.com/questions/4372055/detect-active-window-changed-using-c-sharp-without-polling
'Stephen Lee Parker
Public Event ForeGroundWindowHasChanged(sender As Object, ForeGroundWindowHandle As IntPtr)
Private dele As WinEventDelegate = Nothing
Private Const WINEVENT_OUTOFCONTEXT As UInteger = 0
Private Const EVENT_SYSTEM_FOREGROUND As UInteger = 3
Private m_hhook As IntPtr = IntPtr.Zero
Public Sub Startt()
If m_hhook <> IntPtr.Zero Then
Return
End If
dele = New WinEventDelegate(AddressOf WinEventProc)
m_hhook = SetWinEventHook(EVENT_SYSTEM_FOREGROUND, EVENT_SYSTEM_FOREGROUND, IntPtr.Zero, dele, 0, 0, WINEVENT_OUTOFCONTEXT)
If m_hhook = IntPtr.Zero Then
Throw New Exception("SetWinEventHook failed")
End If
End Sub
Public Sub Stopp()
If m_hhook <> IntPtr.Zero Then
UnhookWinEvent(m_hhook)
End If
End Sub
Private Delegate Sub WinEventDelegate(hWinEventHook As IntPtr,
eventType As UInteger,
hwnd As IntPtr,
idObject As Integer,
idChild As Integer,
dwEventThread As UInteger,
dwmsEventTime As UInteger)
<DllImport("user32.dll")> _
Private Shared Function SetWinEventHook(eventMin As UInteger,
eventMax As UInteger,
hmodWinEventProc As IntPtr,
lpfnWinEventProc As WinEventDelegate,
idProcess As UInteger,
idThread As UInteger,
dwFlags As UInteger) As IntPtr
End Function
<DllImport("user32.dll")> _
Private Shared Function UnhookWinEvent(hWinEventHook As IntPtr) As Boolean
End Function
Public Sub WinEventProc(hWinEventHook As IntPtr,
eventType As UInteger,
hwnd As IntPtr,
idObject As Integer,
idChild As Integer,
dwEventThread As UInteger,
dwmsEventTime As UInteger)
RaiseEvent ForeGroundWindowHasChanged(Me, hwnd)
End Sub
End Class
original source WebBrowser Control how to handle Javascript generated alert window 原始源WebBrowser控件如何处理Javascript生成的警报窗口
Imports System.Runtime.InteropServices
Imports System.Text
Public Class ForeGroundWindowHelper
'source http://www.vbforums.com/showthread.php?761005-WebBrowser-Control-how-to-handle-Javascript-generated-alert-window-%28onbeforeunload%29
'by AgustinTRC
Public Class WindowChildInfo
Public hWnd As IntPtr
Public ClassName As String
Public Text As String
Public Sub New(hwnd As IntPtr, clsname As String, text As String)
Me.hWnd = hwnd
Me.ClassName = clsname
Me.Text = text
End Sub
End Class
Private Const BM_CLICK As Integer = &HF5
Private Const WM_ACTIVATE As Integer = &H6
Private Const WA_ACTIVE As Integer = 1
<DllImport("user32.dll", CharSet:=CharSet.Auto, EntryPoint:="FindWindow")> _
Private Shared Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
End Function
<DllImport("user32.dll", EntryPoint:="SendMessage")> _
Private Shared Function SendMessage(hwnd As IntPtr, wMsg As Integer, wParam As Integer, lParam As Integer) As IntPtr
End Function
' private...
<DllImport("user32.dll", CharSet:=CharSet.Auto)> _
Private Shared Sub GetClassName(ByVal hWnd As System.IntPtr, ByVal lpClassName As StringBuilder, ByVal nMaxCount As Integer)
End Sub
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function GetWindowText(ByVal hwnd As IntPtr, ByVal lpString As StringBuilder, ByVal cch As Integer) As Integer
End Function
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function GetWindowTextLength(ByVal hwnd As IntPtr) As Integer
End Function
Private Delegate Function EnumCallBackDelegate(ByVal hwnd As IntPtr, ByVal lParam As IntPtr) As Integer
Private Declare Function EnumChildWindows Lib "user32" (ByVal hWndParent As IntPtr, ByVal lpEnumFunc As EnumCallBackDelegate, ByVal lParam As IntPtr) As IntPtr
Private Shared children As List(Of WindowChildInfo)
Public Shared Function GetChildWindows(ByVal hwnd As IntPtr) As List(Of WindowChildInfo)
children = New List(Of WindowChildInfo)
EnumChildWindows(hwnd, AddressOf EnumProc, Nothing)
Return children
End Function
Private Shared Function EnumProc(ByVal hwnd As IntPtr, ByVal lParam As IntPtr) As Int32
If hwnd <> IntPtr.Zero Then
children.Add(New WindowChildInfo(hwnd, GetClassNameFromHandle(hwnd), GetText(hwnd)))
End If
Return 1
End Function
Public Shared Function GetClassNameFromHandle(ByVal hWnd As IntPtr) As String
Dim sbClassName As New StringBuilder("", 256)
Call GetClassName(hWnd, sbClassName, 256)
Return sbClassName.ToString
End Function
Private Shared Function GetText(ByVal hWnd As IntPtr) As String
Dim length As Integer = GetWindowTextLength(hWnd)
If length = 0 Then Return ""
Dim sb As New StringBuilder("", length + 1)
GetWindowText(hWnd, sb, sb.Capacity)
Return sb.ToString()
End Function
Public Shared Sub SendClickEvet2Button(ByVal hWnd As IntPtr)
' activate the button
SendMessage(hWnd, WM_ACTIVATE, WA_ACTIVE, 0)
' send button a click message
SendMessage(hWnd, BM_CLICK, 0, 0)
End Sub
End Class
inject javascript. 注入javascript。
(function(w){
w.____oldAlert = w.alert;
w.alert = function(msg){
console.log("alert(", msg, ");");
var result = w.____oldAlert(msg);
console.log("returned ", result);
return result;
};
})(window);
similar code can be applied to confirm
and prompt
so you do not have to depend on many hacks, can possibly read return values. 类似的代码可以应用于
confirm
和prompt
因此您不必依赖许多黑客,可能会读取返回值。 If one day IE decides to change the way it shows the dialogs like Chrome did, your code will still be working 如果有一天IE决定改变它显示像Chrome这样的对话框的方式,那么你的代码仍然有效
I think that if you look at the top answer to this question , you will find what you are looking for. 我想如果你看看这个问题的最佳答案,你会发现你在寻找什么。 The code there is in C, but the responder indicates that all of the necessary information is there.
代码存在于C中,但响应者指出所有必要的信息都在那里。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.