Html 检查 Webbrowser 控件 (vb.net) 中的 Document 中是否存在 HTMLElement
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check if HTMLElement exists in Document in webbrowser control (vb.net)
提问by Jonathan.
I am trying to get the HTML inside a HTMLElement which has an id "block". I have tried:
我正在尝试将 HTML 放入一个 id 为“block”的 HTMLElement 中。我试过了：
If webbrowser1.document.getelementbyid("block") isnot nothing then
MsgBox(webbrowser1.document.getelementbyid("block").innerHTML)
end if
But it keep throwing a NullReferenceException and tells me to check if it null/nothing which is what I'm doing.
但它不断抛出 NullReferenceException 并告诉我检查它是否为空/无，这就是我在做什么。
So how do I check if an element in a HTMLdocument with a certain ID exists?
那么如何检查具有特定 ID 的 HTML 文档中的元素是否存在？
回答by JaredPar
What's likely happening here is that webbrowser1.document is Nothing and that is what's causing the NullReferenceExceptionto be thrown.
这里可能发生的事情是 webbrowser1.document 是 Nothing ，这就是导致NullReferenceException抛出的原因。
Try the following code
试试下面的代码
If webbrowser1.document IsNot Nothing Then
Dim element = webbrowser1.document.getelementbyid("block")
if element isNot Nothing Then
MsgBox(element.innerHTML)
End if
end if
