[RESOLVED]Object reference not set to an instance of an object.[Help]

Ok guys. Im trying to grab a HTML element style with my program, the problem is that when the page is loaded there is no style to that element, then if I click on that element and it has a style.

I have this

vb.net Code:

With WebBrowser1
 
 
                If .Document.GetElementById("idSUOther9").Style is Nothing Then
                    .Document.GetElementById("i1668").InvokeMember("click")
                End If
                If .Document.GetElementById("idSUOther9").Style Is "display: none;" Then
                    .Document.GetElementById("i0116")
                    .Document.GetElementById("i0118")
 
                End If
                tLogin.Stop()
                MessageBox.Show(.Document.GetElementById("idSUOther9").Style)
                Return

then my program crashes here

vb.net Code:

If .Document.GetElementById("idSUOther9").Style is Nothing Then
                    .Document.GetElementById("i1668").InvokeMember("click")
                End If

since idSUOther9 there is no style it cant grab its data. How can I check is "idSUOther9" has a style without crashing my program?

Thank you

I haven't played much with the WebBrowser control and HTML elements so I don't know the best practices with these but one way to solve your issue would be to handle the exception with a try/catch block. If the exception is caught then you know there is no style for "idSUOther9".

Does .Document.GetElementById("idSUOther9") return an object? If IT is producing Nothing, then the InvokeMember line will fail as well.

Basically, an "Object Reference not set to an instance of an object" is a pretty generic error. It's basically saying you're trying to do something to an object that doesn't exist; or use a method or function of an object that doesn't exist.

Quote:

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Originally Posted by Jenner

Does .Document.GetElementById("idSUOther9") return an object? If IT is producing Nothing, then the InvokeMember line will fail as well.

Basically, an "Object Reference not set to an instance of an object" is a pretty generic error. It's basically saying you're trying to do something to an object that doesn't exist; or use a method or function of an object that doesn't exist.

---

Yes. It suppose to return a value. but it crashes since idSUOther9 has to style yet.

What line crashes?

"It suppose to return a value." -- does that mean you don't know for sure that it does? That should be the first thing you should be checking. Try debugging... when it crashes, check the values of your objects... make sure they are what you expect them to be.

-tg

Quote:

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Originally Posted by techgnome

What line crashes?

"It suppose to return a value." -- does that mean you don't know for sure that it does? That should be the first thing you should be checking. Try debugging... when it crashes, check the values of your objects... make sure they are what you expect them to be.

-tg

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It crashes here

vb.net Code:

If .Document.GetElementById("idSUOther9").Style is Nothing Then

because "idSUOther9" in this case doesn't have a style, so it cant grab its data.

so when you check: .Document.GetElementById("idSUOther9") .... you get "something"?

-tg

Yea, try:

Code:

---

If .Document.GetElementById("idSUOther9") IsNot Nothing AndAlso .Document.GetElementById("idSUOther9").Style is Nothing Then
...

---

Quote:

---

Originally Posted by Jenner

Yea, try:

Code:

---

If .Document.GetElementById("idSUOther9") IsNot Nothing AndAlso .Document.GetElementById("idSUOther9").Style is Nothing Then
...

---

---

It works!

Thank you