Webview2 and reading a text box IN the webpage

Thought I'd try and stump you today.
I got WeView2 to show a web page correctly and wondered if its possible to pull the value of a textbox on the web page into the VB form.

Code:

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        Dim jScript As String = "document.getElementById('WH').value;"
        Dim t As Task(Of String) = WebView22.CoreWebView2.ExecuteScriptAsync(jScript)
        Me.WebView21.CoreWebView2.ExecuteScriptAsync(jScript)

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I found this code. Added a button to the form and onclick, run the code, but it does not appear to pull the value over.

Is there an Import I am missing?

You have to actually get the String out of the completed Task. You have two options. You could do this:

vb.net Code:

Dim script = "document.getElementById('WH').value;"
Dim wh2 = Await WebView22.CoreWebView2.ExecuteScriptAsync(script)
Dim wh1 = Await WebView21.CoreWebView2.ExecuteScriptAsync(script)

The Await operator automatically waits for the Task to complete and pulls out the String, but you would have to declare your method Async as well to use it. That is the usual way to go, unless you have a chain of method calls that you cannot make Async. The alternative would be this:

vb.net Code:

Dim script = "document.getElementById('WH').value;"
Dim t2 = WebView22.CoreWebView2.ExecuteScriptAsync(script)
Dim t1 = WebView21.CoreWebView2.ExecuteScriptAsync(script)
Dim wh2 = t2.Result
Dim wh1 = t1.Result

Quote:

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Originally Posted by jmcilhinney

You have to actually get the String out of the completed Task. You have two options. You could do this:

vb.net Code:

Dim script = "document.getElementById('WH').value;"
Dim wh2 = Await WebView22.CoreWebView2.ExecuteScriptAsync(script)
Dim wh1 = Await WebView21.CoreWebView2.ExecuteScriptAsync(script)

The Await operator automatically waits for the Task to complete and pulls out the String, but you would have to declare your method Async as well to use it. That is the usual way to go, unless you have a chain of method calls that you cannot make Async. The alternative would be this:

vb.net Code:

Dim script = "document.getElementById('WH').value;"
Dim t2 = WebView22.CoreWebView2.ExecuteScriptAsync(script)
Dim t1 = WebView21.CoreWebView2.ExecuteScriptAsync(script)
Dim wh2 = t2.Result
Dim wh1 = t1.Result

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Woohoo! This will blow my clients mind :)
Still needs a bit of clean up but will work perfectly. I suppose I can move data from the form TO the web page as well..

Code:

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Private Async Function Button2_ClickAsync() As Task
        Dim script = "document.getElementById('WH').value;"
        Dim WH As String = Await WebView23.CoreWebView2.ExecuteScriptAsync(script)

        TextBox1.Text = WH.ToString

    End Function

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Button2_ClickAsync()
    End Sub

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Many many thanks!

Quote:

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Originally Posted by Juliemac57

Woohoo! This will blow my clients mind :)
Still needs a bit of clean up but will work perfectly. I suppose I can move data from the form TO the web page as well..

Code:

---

   
Private Async Function Button2_ClickAsync() As Task
        Dim script = "document.getElementById('WH').value;"
        Dim WH As String = Await WebView23.CoreWebView2.ExecuteScriptAsync(script)

        TextBox1.Text = WH.ToString

    End Function

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Button2_ClickAsync()
    End Sub

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Many many thanks!

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That's not right. While you generally shouldn't declare a Sub Async, you can specifically for the purposes of event handlers. You should declare your event handler Async and then either get rid of the second method and put all the code in the event handler or else Await the second method when you call it from the event handler.

Quote:

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Originally Posted by jmcilhinney

That's not right. While you generally shouldn't declare a Sub Async, you can specifically for the purposes of event handlers. You should declare your event handler Async and then either get rid of the second method and put all the code in the event handler or else Await the second method when you call it from the event handler.

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That has been cleaned up. Thanks