WebBrowser 不会触发 DocumentCompeted 事件或打印

Question

所以一周多来，我一直在寻找解决方案，但无济于事。我有一个程序需要能够打印 htm(l) 文件，但我很难让它遵守。

这是我目前正在使用的代码：

Private Sub HtmlPrinterLaunch(i As Integer)
    'Dim htmlWBPrinter As New WebBrowser()
    'AddHandler htmlWBPrinter.DocumentCompleted, New WebBrowserDocumentCompletedEventHandler(AddressOf HtmlPrinter)
    'htmlWBPrinter.Visible = True
    'htmlWBPrinter.ScriptErrorsSuppressed = False
    'htmlWBPrinter.Show()
    ''frmHTMLPrint.wbPrintHtml.AllowNavigation = True
    ''AddHandler frmHTMLPrint.wbPrintHtml.DocumentCompleted, AddressOf HtmlPrinter
    ''frmHTMLPrint.wbPrintHtml.Visible = False

    ''frmHTMLPrint.wbPrintHtml.Navigate("file:///" & IO.Path.GetFullPath(_prints(i).SourcePathFileName))
    ''Application.Run(frmHTMLPrint)

    ''Dim appPath As String = Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase)
    ''Dim reportPath As String = Path.Combine(appPath, Path.GetFileName(_prints(i).SourcePathFileName))

    ''htmlWBPrinter.Url = New Uri(reportPath) 'New Uri(Path.Combine("file:///", reportPath)) 'New Uri("file://" & IO.Path.GetFullPath(_prints(i).SourcePathFileName))
    'htmlWBPrinter.Url = (New Uri(Path.Combine("file:///" & IO.Path.GetFullPath(_prints(i).SourcePathFileName))))
    'While ((htmlWBPrinter.DocumentText = ""))
    '    Thread.Sleep(10000)
    'End While
    'htmlWBPrinter.ShowPrintDialog()
    '' htmlWBPrinter.Dispose()
    Dim wb As New WebBrowser
    AddHandler wb.DocumentCompleted, Sub() If wb.ReadyState = WebBrowserReadyState.Complete Then wb.Print()
    wb.ScriptErrorsSuppressed = True
    Dim url As New Uri(Path.Combine("file:///" & IO.Path.GetFullPath(_prints(i).SourcePathFileName)))
    wb.Navigate(url)
End Sub

Private Sub HtmlPrinter(sender As Object, e As WebBrowserDocumentCompletedEventArgs)
    state = 4
    Dim wbPrinter As WebBrowser = CType(sender, WebBrowser)
    wbPrinter.Print()
    wbPrinter.Dispose()
    'frmHTMLPrint.BeginInvoke(New Action(Sub() frmHTMLPrint.Close()))
End Sub

如您所见，我在那里进行了几次尝试（保留了一些可以工作的旧代码，但我宁愿不使用它，因为我不断收到弹出窗口）

一些可能相关的问题：

-WebBrowser 状态停留在加载（1）

-即使我直接传递，Url 也不会随 file:///path 更新

简而言之，我的代码中的 WebBrowser 控件不会触发 DocumentCompleted 事件，也不会打印出文件。我需要此代码来打印文档而无需用户输入。我在这里错过了什么？

编辑：

所以我又搞砸了一些。我在自己的表单上有 webbrowser 控件，当从主线程调用时，我可以让它加载/打印，但我没有运气调用它。我当前的调用代码：

If wbPrintHtml.InvokeRequired Then
            If url.SourcePathFileName = "about:blank" Then
                wbPrintHtml.Invoke(CType(Sub()
                                             wbPrintHtml.Navigate(url.SourcePathFileName)
                                         End Sub, MethodInvoker))
            Else
                wbPrintHtml.Invoke(CType(Sub()
                                             wbPrintHtml.Navigate("file:///" & url.SourcePathFileName)
                                         End Sub, MethodInvoker))
            End If
        Else
            If url.SourcePathFileName = "about:blank" Then
                wbPrintHtml.Navigate(url.SourcePathFileName)
            Else
                wbPrintHtml.Navigate("file:///" & url.SourcePathFileName)
            End If
        End If

Answer 1

我终于让它按预期工作了。这不是世界上最漂亮的东西，但它可以发挥作用，我可以接受。

Public Class frmHTMLPrint

Public Shared formHandle As frmHTMLPrint

Private Sub wbPrintHtml_DocumentCompleted(sender As Object, e As WebBrowserDocumentCompletedEventArgs) Handles wbPrintHtml.DocumentCompleted
    Dim wbPrinter As WebBrowser = CType(sender, WebBrowser)
    If wbPrinter.ReadyState = WebBrowserReadyState.Complete AndAlso Not wbPrinter.Url.ToString() = "about:blank" Then
        wbPrinter.Print()
    End If
End Sub

Shared Function setURL(url As Reporter.ReportServer.PrintMessageType) As Boolean
    If formHandle.wbPrintHtml.InvokeRequired Then
        If url.SourcePathFileName = "about:blank" Then
            formHandle.wbPrintHtml.Invoke(CType(Sub()
                                                    formHandle.wbPrintHtml.Navigate(url.SourcePathFileName)
                                                End Sub, MethodInvoker))
        Else
            formHandle.wbPrintHtml.Invoke(CType(Sub()
                                                    formHandle.wbPrintHtml.Navigate("file:///" & url.SourcePathFileName)
                                                End Sub, MethodInvoker))
        End If
        Dim wbReady As WebBrowserReadyState
        formHandle.wbPrintHtml.Invoke(CType(Sub()
                                                wbReady = formHandle.wbPrintHtml.ReadyState
                                            End Sub, MethodInvoker))
        While ((Not wbReady = WebBrowserReadyState.Complete))
            Application.DoEvents()
            formHandle.wbPrintHtml.Invoke(CType(Sub()
                                                    wbReady = formHandle.wbPrintHtml.ReadyState
                                                End Sub, MethodInvoker))
        End While
        Return wbReady = 4
    Else
        If url.SourcePathFileName = "about:blank" Then
            formHandle.wbPrintHtml.Navigate(url.SourcePathFileName)
        Else
            formHandle.wbPrintHtml.Navigate("file:///" & url.SourcePathFileName)
        End If
        While ((Not formHandle.wbPrintHtml.ReadyState = WebBrowserReadyState.Complete))
            Application.DoEvents()
        End While
        Return formHandle.wbPrintHtml.ReadyState = 4
    End If
End Function

Private Sub frmHTMLPrint_Load() Handles Me.Load
    InitializeComponent()
    Dim wbInitializer As New Reporter.ReportServer.PrintMessageType
    formHandle = Me
    wbInitializer.SourcePathFileName = "about:blank"
    setURL(wbInitializer)
End Sub

结束类