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RichTextBox format line by button click vb.net 2010

Hi Experts,

I'm trying writing to write a winform app with a RTB and button. The button follows the cursor/caret up or down depending on carriage return (which works great thanks to the mighty kaufmed from previous question... Previous Question

The purpose of the button is to format whatever text is on same line as button.
for example: if i want all the text on line 5 to change color to GREEN, then pressing this button will do so. and not continue on another line.

I found the code beow (from a google search) and inserted into my button click, which works great if I don't add Label1.Text in line 2 / 4... works with array (actual number).

1    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
2    RichTextBox1.SelectionStart = RichTextBox1.Text.IndexOf(RichTextBox1.Lines(Label1.Text))  'Sets the selection 3    length as the length of the line 3. At this point, we have now set the start and end positions of the selection.
4    RichTextBox1.SelectionLength = RichTextBox1.Lines(Label1.Text).Length
5    RichTextBox1.SelectionColor = Color.Green   'Sets the color of the selected text to Green.
6
7    End Sub

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The ERROR I'm getting is

Message=Index was outside the bounds of the array.

because Label1 shows line numbers... I thought it would be easy to pass it through a label.

Fernando Soto

Hi Roberto;

You should have gotten an error pointing to this part of the following line of code, RichTextBox1.Lines(Label1.Text), because the lines property is an array of String's and you are indexing that array with a string value from Label1.Text. You need an Integer value to do that indexing.

RichTextBox1.SelectionStart = RichTextBox1.Text.IndexOf(RichTextBox1.Lines(Label1.Text))

RobertoFreemano

ASKER

Hi Fernando,

I understand that you're saying... it's just connecting the dots now. I 'm trying to draw from lineCount, but it's encased in RichTextBox1_TextChanged....

RichTextBox1.SelectionStart = RichTextBox1.Text.IndexOf(RichTextBox1.Lines(lineCount)) ' would be better, but it doesn't work.

Fernando Soto

Try it like this Roberto and see if it gives you what you are looking for.

RichTextBox1.SelectionStart = RichTextBox1.Text.IndexOf(RichTextBox1.Lines.Count)

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RobertoFreemano

ASKER

Thanks Fernando,

I get the following...
Message=

InvalidArgument=Value of '-1' is not valid for 'SelectionStart'.

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Fernando Soto

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RobertoFreemano

ASKER

ah yes, I think you've "Hit the nail on the head"... You're right... I guess what i want is to set the format anywhere along the line (instead of at the font).
I've been trying to get the BUTTON to highlight the line before actioning it.
Since your last comment, I've been experimenting with ysendkeys(end)

RichTextBox1.Focus()
        RichTextBox1.Focus()
        SendKeys.Send("{HOME}+{END}")
        RichTextBox1.SelectionAlignment = HorizontalAlignment.Center
        RichTextBox1.AppendText(Environment.NewLine)
        RichTextBox1.ScrollToCaret()
        RichTextBox1.SelectionAlignment = HorizontalAlignment.Left

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This seems to work for me ;)

RobertoFreemano

ASKER

Thanks Fernando! Super Job ;)

Fernando Soto

Not a problem Roberto, glad I was able to help.