I am working on a vb.net program, I want to click a hyperlink on a page, the source look like this:
messages for Today, 2010-10-19
I want to check it everyday too!
I tried to click it with the following methods(Both couldn't click the link!):
Dim theElementCollection As HtmlElementCollection
Dim ctrlIdentity As String
theElementCollection = WebBrowser1.Document.GetElementsByTagName("a")
For Each curElement As HtmlElement In theElementCollection
ctrlIdentity = curElement.GetAttribute("innerText").ToString
If ctrlIdentity = Today.Date.ToString(Today.Date.ToString("dd")) Then
curElement.InvokeMember("click")
End If
Next
and I tried this code too:
If Me.WebBrowser1.Document.Links(i).InnerHtml.Contains(Today.Date.ToString("dd")) Then
Me.WebBrowser1.Document.Links(i).InvokeMember("Click")
End If
Next
Any help would be appreciated! Thanks!
I've found that the best way to click links in a WebBrowser is using javascript. Try something like this:
WebBrowser1.Navigate("javascript:function%20x(){document.getElementById('foo').click()}x()")
You'll need to rewrite your above code in javascript but that's a piece of cake. You can test your javascript by copy-pasting it directly into the browser's location bar. This is also a reliable way to fill out forms.
Caveats:
Notice how the work that I want to do is wrapped in a function. This is needed if you want the javascript to do multiple statements. Wrap in a function and then invoke the function.
You can't navigate to a URL more than around 500 characters. (The limit isn't exactly 512 but it's close.) There's no warning, either, so keep it in mind.
Make sure you wait until the page is loaded. The ReadyState = Complete and IsBusy = False.
Clicking like this doesn't always generate the usual events that you get when you click a link.
"%20" is hex for space. I don't recall if this was strictly necessary in my code. Try it both ways.
Related
I want to get the value of the src attribute (https://www.google.com) to a string from a web browser HTML elements. The code of element is:
<img src="https://www.google.com" height="500" width="500">
Code I have tried is:
For Each o As HtmlElement In WebBrowser1.Document.GetElementsByTagName("img")
If o.GetAttribute("height") = "500" Then
Dim url As String = o.GetAttribute("src").ToString
Exit For
End If
Next
String url is empty every time I also tried to get url in textbox but its also empty.
problem is that is not a server side control, it is plain html. to make matters worse there are not classes or ID's to make it easier to isolate which control u want to target. Also javascript could be generating that image so that could make it harder.
I have a problem with the snippet of the code I have got to extend and improve. It is not my original code and I cannot change the logic that much of it, just to be clear.
I have one main form called MDIServer, which has a timer set for every second. In Timer.Tick I have some other code which works fine (timer is running okay). Newly, I had to check there, if one form is Active and if so, change some stuff (labels text and tags) in that form and refresh it.
I add there this code:
If IsActiveForm("frmName") Then
frmName.ChangeSomething()
End If
The Sub ChangeSomething is, how you can see, located in the form I want to refresh and do the changes. In that function I simply change the label text and tags of few controls.
My question is: Form is not refreshing => labels are not visible changed, why?
I think I tried already almost anything with Refresh() function in the ChangeSomething() function or in the timer after I called this function. Also I tried to add there new timer (in frmName) and do the changes there, which works perfectly with
Label.Text = "something new"
Label.Refresh()
So I guess problem is somewhere with the refreshing form from Timer in different form. I also tried to do it with my own InvokeReguired() function etc...
P.S. When I am debugging the code, labels and tags are changing and every single function which has to be called, is called, but it is just not visible on the form itself.
EDIT Info
formName is not declared in MDIServer explicitely and in this case and many other cases, forms are used as default instances. Timer is from System.Windows.Forms.Timer. Also MDIServer is not a MDIParent of the formName and I cannot use Me.ActiveMdiChild Is. Lets just say, these two forms are not dependent on each other in any way.. and everything is done through name of the form (default instance, so nothing like Dim frm As Form and frm = frmName).
I would be really glad for any tip or anything :D
Thanks guys,
Vojta
So, I fixed my problem after some research and the problem was (expected) that I am not calling the subroutine ChangeSOmething() for one specific instance of the form frmName. So I had to change my code, that I will call it exactly for the instance which is active and visible.
New code looks like this:
Dim frmCollection = Windows.Forms.Application.OpenForms
Dim listfrmname = frmCollection.OfType(Of frmName).ToList()
If listfrmName.Count > 0 Then
Dim tmpFrm As frmName = listVZT15.Last()
tmpFrm.ChangeSomething()
End If
I also could not use combination of frmCollection.OfType(Of frmName).Any and frmCollection.Item("frmName"), because when I was closing the form and opening again, it created new and new instances (I dont know, why it is not closing the old one, but like I said, it is not my code). So the logic is, to list all open forms of the needed type, and then take the last instance from that list and for that instance call the subroutine. Also Me.Refresh() is placed in the subroutine ChangeSomething() itself.
Thanks everyone for help, it surely helped me to understand, how the instances works here.
I had searched a lot how to display a Msgbox that will not wait the user input (pressing ok or cancel).
I found 3 solutiuons to this.
1- Display the MsgBox() in another thread or using BackgroundWorker()
2- Create a form that display the message, then closed the form by a timer and use it instead of Msgbox()
3- Using the API MessageBoxA()
Let say I have a loop from 1 to 100, and I want display a message for the i(counter)
When I test above 3 ways, I found that this is not the right way of doing it, I don't need a msgbox() to close by it self after showing the message, because that will display 100 dialog.
What I realy want is to display ONLY 1 MsgBox() and change the text accordingly.
I managed to do this using a a Form() as class and I did it using Application.DoEvents
I know it can be done using BackgroundWorker or Threading since alot of people advice against using Application.Doevents
Here is my code
Dim oWW As New WaitWindow With {.TopLevel = True,.TopMost = True,.StartPosition = FormStartPosition.CenterScreen}
oWW.Show(Me)
For i = 1 to 100
Threading.Thread.Sleep(500) ' Just to slowdown execution
oWW.SetMessage("Counter = " + i.ToString)
Next
oWW.Dispose()
Public Class WaitWindow
Sub SetMessage(ByVal Message As string)
lbl_message.Text = Message
Application.DoEvents
End Sub
End Class
WaitWindow is not more than a Form base class with a label (lbl_message)
That code works fine (display WaitWindowForm on center of currently displayed form only once, then I change the text)
I have 3 questions :
1- How to display the WaitWindowForm in the top right corner of my working form?
2- Is it possible to display the normal MsgBox() or MessageBox.Show() only once, then capture the text displayed and change it?
3- Which one is suitable for my issue (BackGroundWorker or Threading) and what the code in WaitWindow class I post will be if I decided to use Backgroundworker or Threading instead of Application.DoEvents (Changing the label text not showing new form with new text) ?
3 questions in one post.. humm.. who cares, I am not the one who will answer lol :)
Thanks in advance.
I think the issue that you're really encountering is that you're trying to use a message box for something it's not suited for. If you want to have text that constantly changes just add a text box in the upper right corner of your application and adjust it every time a new message needs to be shown.
You can also look up dialogu windows (search ".showdialog() vb.net" in google) might help as well.
I am trying to make a form on VB.NET that when a certain webpage is loaded into the web browser (in this case its a .txt file with a string of numbers). It will look for those numbers and if it finds them it will close that form and open another. I have tried to do it many times and my latest attempts came out with this code. Any help would be appreciated.
Dim passcontents As String
passcontents = WebBrowser.DocumentText = "test.com/test.txt"
If WebBrowser.DocumentText = "test.com/test.txt" And passcontents Then
ActualGen.Show()
Me.Close()
Else
End If
There are a couple of basic problems with the code you've posted.
1) Are you trying to test passcontents as a boolean or a string? You've defined it as a String, but then you are trying to assign the equality of two other strings to it, as you would a Boolean.
Try setting Option Strict On at the top of your code - it gives a few more helpful pointers to check in this case.
2) The If... Then condition is checking the same data as passcontents (may) already be providing. Are you just trying to check that the correct page is loaded, or do you want to check for certain page contents as well?
You appear to be getting mixed up between the browser's document URL and the loaded document contents.
Ok so i'm trying to make multiple webrequests, but in a different way.
i'm trying to let my users add the websites on each line of a richtextbox and when they click a button it will run this:
Dim request As WebRequest = WebRequest.Create("Website")
But not for the hole richtextbox, but for every line, so say the richtextbox has all these lines:
google.com
facebook.com
youtube.com
and once they click the button, those sites will be put into the space where it says Website.
If anyone can help me with this, thank you!
Also sorry if this is messy, I don't think there's any other way to present this information!
This could get you started. Textboxes have a Lines property that contains a collection of strings from each line of the textbox (See this MSDN page for reference)
Dim arrUrls() As String = RichTextBox1.Lines
For i As Integer = 0 To UBound(arrUrls)
If Not arrUrls(i).Length=0 Then Dim request As System.Net.WebRequest = System.Net.WebRequest.Create(arrUrls(i))
Next