Is there a way to retrieve text from a webpage to a TextBox in VB.NET?-CodePudding

Let say I have a TextBox1 and a SaveButton. A website "www.example.com/code1.text" with just a content:

How to retrieve this 303981 to a TextBox? Do we need a WebBrowser1?

Please help me I'm self learning and beginner also.

CodePudding user response：

Look at the System.Net.WebClient type.

Using wc As New WebClient()
    TextBox1.Text = wc.DownloadString("www.example.com/code1.text")
End Using

CodePudding user response：

You need to place a webbrowser control on your form. I would use CefSharp for this (see: https://www.youtube.com/watch?v=6d-AgfFzr70)

then you can do something like:

settings = New CefSettings
CefSharp.Cef.Initialize(settings)
browser = New ChromiumWebBrowser("www.google.com")

Which loads google.com, just change it to the page you want to load.

Now check your website and see if you can get that textbox value by javascript from the console (F12). Check the source if you can access it with it's ID or that you need to use it's class.

for example:

document.getElementsByClassName('textboxclass')[0].value;

if you manage to get the right value back in your browser console, you can go ahead in your program and do somethinh like:

Dim task As Task(Of JavascriptResponse) = browser.EvaluateScriptAsync(code)

where code contains your javascript.

you may do something like:

task.ContinueWith(

Sub(t)
            Try
                If t.IsFaulted = False And t.Result IsNot Nothing Then
                    Dim response = t.Result 'Error: Result is not a member of Task' 
                    If response.Success And response.Result IsNot Nothing Then
                        taskResult = response.Result
                    Else
                        taskResult = "bad result"
                    End If
                End If
            Catch ex As Exception
                'Dbg("!!!!!!!!!!!!!!! Exception: " & ex.ToString)
                taskResult = ex.ToString
            End Try
        End Sub)

to get the result in a string.