Question

嘿！的

简单的问题，有什么方法可以让webbrowser等到元素存在？我不是一个了不起的编码员，所以这是我尝试做的最好的例子 -

            Do While PageLoaded = False
            Dim OObject As Object
            OObject = WebBrowser1.Document.GetElementById("Element-That-I-Need-Loaded")
            If (OObject Is Nothing) Then
                Pageloaded = False
            Else
                PageLoaded = True
            End If
        Loop

问题在于元素没有ID，所以当我尝试点击它时，我必须做这样的事情 -

            For Each altelm As HtmlElement In WebBrowser1.Document.GetElementsByTagName("SPAN")
            If altelm.GetAttribute("classname").ToString = "Classname-of-Element-I-Need-Loaded" Then
                altelm.Focus()
                altelm.InvokeMember("click")
            End If

如果措辞不当，我道歉，我是新手：）

谢谢！的

Answer 1

使用定期检查元素的计时器。在DocumentCompleted事件中启动计时器，然后在找到元素后停止它。

Private WithEvents WaitTimer As New Timer With {.Interval = 250}

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    WebBrowser1.Navigate("http://www.somewebsite.com/")
    AddHandler WebBrowser1.DocumentCompleted, AddressOf SomeWebsite_DocumentCompleted
End Sub

Private Sub SomeWebsite_DocumentCompleted(sender As Object, e As WebBrowserDocumentCompletedEventArgs)
    WaitTimer.Start()
    RemoveHandler WebBrowser1.DocumentCompleted, AddressOf SomeWebsite_DocumentCompleted
End Sub

Private Sub WaitTimer_Tick(sender As Object, e As EventArgs) Handles WaitTimer.Tick
    'Look for the element every time the timer ticks.
    For Each altelm As HtmlElement In WebBrowser1.Document.GetElementsByTagName("SPAN")
        If altelm.GetAttribute("className") = "Classname-of-Element-I-Need-Loaded" Then 'No need to call ToString() since GetAttribute() already returns a string.
            altelm.Focus()
            altelm.InvokeMember("click")
            WaitTimer.Stop() 'Element found, stop the timer.
        End If
    Next
End Sub

VB Web浏览器：等到元素出现

1 个答案: