String Functions Not Working?

[Raeki]

Hi, I'm trying to make code that inserts something into a textbox. However, it appears the insert and remove code isn't working. Here's the code:

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim a As Integer = TextBox2.SelectionStart
        Dim b As Integer = TextBox2.SelectionStart + TextBox2.SelectionLength
        TextBox2.Text.Insert(b, "[/i]")
        TextBox2.Text.Insert(a, "[i]")
    End Sub

Whenever I click Button 3 nothing happens. Anyone know what's wrong?

Ty in advance

[aashish_9601]

You must assign the value returned by Insert function back to the textbox text

TextBox2.Text = TextBox2.Text.Insert(...)

[Raeki]

tyvm lol silly me

anyways, now my problem is that whenever I do the insert code, it takes me to the top of the textbox.

any way to keep the position?
I googled it but the few results didn't work when I put it in

And also, I have the same problem selecting text in a textbox - anyone know how i get it to select a specific part of text in a textbox? (i have stored the start and legnth as a variable) nothing happens when I press the button to run the code

ty

[chris128]

anyways, now my problem is that whenever I do the insert code, it takes me to the top of the textbox.

Try using the ScrollToCaret method after you edit the text, e.g:

TextBox2.Text = TextBox2.Text.Insert(a, "[i]")
TextBox2.ScrollToCaret()

And also, I have the same problem selecting text in a textbox - anyone know how i get it to select a specific part of text in a textbox?

Use the Select method, like so:

TextBox2.Select(0, 10) 'This example would select the first 10 characters obviously

Just be aware that if you are doing this from a button click or something else that takes focus away from the textbox then you will not actually see the text as being selected. Just like you wouldn't if you manually selected some text and then clicked another control.

[Raeki]

Ok ty - now I have a third problem lol:

this is my code

Dim a As Integer = TextBox2.SelectionStart
        Dim b As Integer
        If TextBox2.SelectedText = "" Then
            b = 0
        Else
            b = TextBox2.SelectionStart + TextBox2.SelectionLength
        End If
        MsgBox(b)
        MsgBox(a)
        TextBox2.Text = TextBox2.Text.Insert(a + b, "[/b]")
        TextBox2.Text = TextBox2.Text.Insert(a, "[b]")
        TextBox2.Select(a + 3, b)
        TextBox2.ScrollToCaret()

now whenever I highlight a single "+" sign in my textbox, I get an error

anyone know why? i looked at the error and couldn't figure it out

i msgboxed the two integers a and b and both came out normal

ty

[chris128]

Maybe if you tell us what the error is and show us the code where you try to highlight a + then we might have a clue what the problem is

[Raeki]

Ok lol yah - idk why I'm back and the problem is gone.

Anyone, to clarify, I want to know the best way to insert text into a textbox when a button is clicked, without changing the scrollbar. I've tried tons of things even copy and paste (paste code pastes my clipbord three times?) and the closest I can get is using the scrolltocaret... but even then it changes the screen a bit.

can anyone give me any insight on a better way to do this?

[jmcilhinney]

Whenever you set the Text property of the TextBox you are basically clearing the current contents and replacing it with new contents. The old contents is completely gone so the old caret position, etc, is completely gone.

[Raeki]

Lol yah I know - so is there a way to insert the text without replacing everything? Or keep the exact position?

[Sitten Spynne]

Before changing the text, save the old selection information. After replacing the text, restore the old selection information.

Dim oldSelectionStart As Integer = txtText.SelectionStart
Dim oldSelectionLength As Integer = txtText.SelectionLength

' perform replacements

txtText.SelectionStart = oldSelectionStart
txtText.SelectionLength = oldSelectionLength

This will only restore the index and length; it won't necessarily have the same words selected in the text. If you want to leave the same words highlighted, you'll have to do more work to figure out what words were highlighted, then try to find them in the new text so you can highlight them. Since you're replacing text, there's no guarantee the words will still be there when you highlight again.

I just tried a few text editors out and it looks like doing a replace usually kills your selection; likely for this reason. Visual Studio keeps the same selection, but it has a more intimate knowledge of the things you have highlighted and parsing code is a different matter entirely from parsing normal text.

[JuggaloBrotha]

Or maybe he could just highlight the newly inserted text to show the user what was inserted.

Just a suggestion

[Raeki]

Well here's my problem: I'm making a BBCode editor. So there are buttons to add bold and color and etc. codes around the selected text or wherever the cursor is it. That's fine. However, inserting it, as someone said, is like replacing the whole text. At the moment, I have code that selects the original text, and navigates to it. This is better, as I get back to a general location, but it is awkward since scrolltocaret makes the selected text at the bottom of the textbox. So this is annoying. Is there any way to keep the exact position? Or inserting text without moving it.

[jmcilhinney]

I'm ashamed that I didn't think of this earlier but, if you want to insert text, you should probably set the SelectionStart and SelectionLength properties and then set the SelectedText property, e.g.

Dim selectionLength As Integer = Me.TextBox1.SelectionLength
 
If selectionLength > 0 Then
    Dim startIndex As Integer = Me.TextBox1.SelectionStart
    Dim endIndex As Integer = startIndex + selectionLength
 
    'Insert the closing tag.
    Me.TextBox1.SelectionStart = endIndex
    Me.TextBox1.SelectionLength = 0
    Me.TextBox1.SelectedText = "[/b]"
 
    'Insert the opening tag.
    Me.TextBox1.SelectionStart = startIndex
    Me.TextBox1.SelectionLength = 0
    Me.TextBox1.SelectedText = "[b]"
 
    'Reselect the original text.
    Me.TextBox1.SelectionStart = startIndex + "[b]".Length
    Me.TextBox1.SelectionLength = selectionLength
End If

[Raeki]

Lol tyvm it worked great

[Raeki]

Hmm there seems to be one really random and annoying problem.

I used your code, for bold, underline, and italics (except i changed the to of course). I also changed If selectionLength > 0 Then to If selectionLength >= 0 Then

I don't know why, the code works perfectly for bold and underline, but for the italics code, if there is nothing selected, it adds like 10 spaces between the two tags. It's identical code, except for the tags it inserts (which are the same character length anyways), and the other two have no problems. Anyone know why?

Dim selectionLength As Integer = Me.TextBox2.SelectionLength
        If selectionLength >= 0 Then
            Dim startIndex As Integer = Me.TextBox2.SelectionStart
            Dim endIndex As Integer = startIndex + selectionLength

            'Insert the closing tag.
            Me.TextBox2.SelectionStart = endIndex
            Me.TextBox2.SelectionLength = 0
            Me.TextBox2.SelectedText = "

"
            'Insert the opening tag.
            Me.TextBox2.SelectionStart = startIndex
            Me.TextBox2.SelectionLength = 0
            Me.TextBox2.SelectedText = "[b]"
            'Reselect the original text.
            Me.TextBox2.SelectionStart = startIndex + "[b]".Length
            Me.TextBox2.SelectionLength = selectionLength
end if

        Dim selectionLength As Integer = Me.TextBox2.SelectionLength
        If selectionLength >= 0 Then
            Dim startIndex As Integer = Me.TextBox2.SelectionStart
            Dim endIndex As Integer = startIndex + selectionLength

            'Insert the closing tag.
            Me.TextBox2.SelectionStart = endIndex
            Me.TextBox2.SelectionLength = 0
            Me.TextBox2.SelectedText = "

"
            'Insert the opening tag.
            Me.TextBox2.SelectionStart = startIndex
            Me.TextBox2.SelectionLength = 0
            Me.TextBox2.SelectedText = "[i]"
            'Reselect the original text.
            Me.TextBox2.SelectionStart = startIndex + "[i]".Length
            Me.TextBox2.SelectionLength = selectionLength
        End If

[Pradeep1210]

Isn't this all the code you need?

TextBox1.SelectedText = "[I]" & TextBox1.SelectedText & "[/I]"
TextBox1.Select()

[Pradeep1210]

If you want to keep the original text selected while putting the tags then, save the current position and selection length and reapply them after replacing the text.

Dim ss, sl As Integer
ss = TextBox1.SelectionStart
sl = TextBox1.SelectionLength
TextBox1.SelectedText = "[I]" & TextBox1.SelectedText & "[/I]"
TextBox1.SelectionStart = ss + 3            '<--  +3 is length of "[I]" tags
TextBox1.SelectionLength = sl
TextBox1.Select()

[Raeki]

No, I tried that and it doesn't keep the exact position.

I don't know why, but the code tags got split in two (two codes made it 4)

But essentially, why does the identical code produce different results? I tried copying the exact code for bold into italics, and the italics button still makes everything wonky :S

[Pradeep1210]

I'm not sure I got exactly what you are trying to say.
But this works perfectly ok as expected for me:

Private Sub InsertBBTags(ByVal tag As String)
    Dim ss, sl As Integer
    ss = TextBox1.SelectionStart
    sl = TextBox1.SelectionLength
    TextBox1.SelectedText = "[" & tag & "]" & TextBox1.SelectedText & "[/" & tag & "]"
    TextBox1.SelectionStart = ss + tag.Length + 2  
    TextBox1.SelectionLength = sl
    TextBox1.Select()
End Sub

We can call it like this:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    'to surround with [I]...[/I]
    InsertBBTags("I")
 
    'to surround with [CODE]...[/CODE]
    InsertBBTags("CODE")
End Sub

Since some characters are being inserted, a minor change in the scrollbar position should be ok. But the content under selection should still be in view.