Question

I’m trying to enable tabs functionality in the WebBrowser control. I have a TabControl hosting WebBrowser controls in each tab. And a multiline enables Textbox to enter the sites. It looks something like this,

An this is the code I have.

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim m As String()
        Dim w As New WebBrowser
        Dim i As Integer

        TabControl1.TabPages.RemoveAt(0)

        m = TextBox1.Text.Split(Environment.NewLine)

        For Each k As String In m
            TabControl1.TabPages.Add(i, k.Trim)
            TabControl1.SelectedTab.Controls.Add(w)
            w.Dock = DockStyle.Fill
            w.Navigate(k)
            i = i + 1
        Next

    End Sub
End Class

Its supposed to take each string(URL) and execute them in separate tab. It opens up the correct number of tabs according to the user input. However it only executes the last URL.

I think I have an idea as to what’s wrong here. This line

TabControl1.SelectedTab.Controls.Add(w)

It adds the WebBrowser control to the TabControl at the SelectedTab position. Since the default selected tab is the first, it only adds it to the first tab therefore executing only that browser.

I want to know how I can select the next tab from the loop as the SelectedTab so that when the loop runs again and again, it would keep adding WeBrowser controls to each tab.

Answer 1

In your example you need to move the creation for ‘w‘ (WebBrowser) into the For Each loop. You are using one instance of ‘w‘ that is essentially moved into between the tabs whilst the loop executes.

You want something like this

For Each k As String In m
    Dim w As New WebBrowser() ' <-- Move the construction of WebBrower into the loop
    TabControl1.TabPages.Add(i, k.Trim)
    TabControl1.SelectedTab.Controls.Add(w)
    w.Dock = DockStyle.Fill
    w.Navigate(k)
    i = i + 1
Next

Also I’m unsure if TabPages.Add will update SelectedTab, you may want to consider constructing new instances of TabPage explicitly, within you loop to ensure you add the WebBrowser to the appropriate TabPage.

Dim tabPage As New TabPage(url) ' <-- 'k' in your example
tabPage.Controls.Add(w) 
w.Dock = DockStyle.Fill
w.Navigate(url) 
TabControl1.TabPages.Add(tabPage) ' <-- Add the tabPage to the TabControl