CODEWITHSUNDEEP
vb.netwinformsfontsrichtextboxsyntax-highlighting
user1938775
user1938775

Reputation:

Highlight text in a richtextbox in windows forms

How to make when i type in a RichTextBox a certain word it gets highlited?

how do i find words in the text to use SelectionColor or SelectionFont

For example: i want that all times that the word "hello" appear in the RichTextBox it turn to bold or turn into a color...

Then if i open my program and type "hello, how are you?" the word hello turns into bold... any idea? (my idea is to make a text editor with syntax highlight that ill specify the words)

(sorry if there is another question like that, i tried to search but i didn't find a answer that helped me)

its windows forms, visual basic

Upvotes: 4

Views: 15717

Answers (5)

Hannington Mambo
Hannington Mambo

Reputation: 1090

I find the above codes to be too lengthy/complicated for a simple task...

    Dim c As Integer = 0

    Dim o As Integer = 0
    Dim s As Integer = 0

    Dim txt As String = RTB.Text
    RTB.BackColor = Color.Black

    Dim starts As Integer = 0

    Do While txt.Contains(key) ' this avoids unnecessary loops

        s = txt.IndexOf(key)
        starts = s + o
        RTB.Select(starts, key.Length)
        RTB.SelectionBackColor = Color.Yellow
        RTB.SelectionColor = Color.Blue

        txt = txt.Substring(s + key.Length)
        o += (s + key.Length)

        c += 1

    Loop
    Me.Status.Text = c.ToString() & " found" ' and the number found

Upvotes: 0

kb.baby
kb.baby

Reputation: 1

Private Sub RichTextBox1_DragOver(sender As Object, e As DragEventArgs) Handles RichTextBox1.DragOver

    Dim p As Point
    p.X = e.X
    p.Y = e.Y
    Dim num As Integer
    Dim rightTXT As String
    Dim leftTXT As String
    Dim textpart As String
    Dim TSelect As Boolean
    Dim curpos As Integer = RichTextBox1.GetCharIndexFromPosition(RichTextBox1.PointToClient(p))
    Dim PosStart As Integer

    TSelect = False
    If e.Data.GetDataPresent(DataFormats.StringFormat) Then

        e.Effect = DragDropEffects.All

        Try
            leftTXT = Microsoft.VisualBasic.Left(RichTextBox1.Text, curpos)
            If InStr(leftTXT, "%", CompareMethod.Text) Then
                rightTXT = Microsoft.VisualBasic.Right(RichTextBox1.Text, Len(RichTextBox1.Text) - curpos)

                If InStr(rightTXT, "%", CompareMethod.Text) Then
                    PosStart = curpos - InStr(StrReverse(leftTXT), "%") + 1
                    num = curpos + InStr(rightTXT, "%") - PosStart - 1

                    textpart = (RichTextBox1.Text.Substring(PosStart, num).TrimEnd)

                    Label3.Text = "mouse drag over:" + textpart
                    Label5.Text = num.ToString()

                    If ListBox1.Items.Contains(textpart) Then
                        TSelect = True
                    End If
                End If
            End If
        Catch ex As Exception
            Label4.Text = ex.ToString()
        End Try

    End If

    If TSelect Then      
        Me.RichTextBox1.Select(PosStart - 1, num + 2)
        wordSearch = RichTextBox1.SelectedText

        Label4.Text = "word drag state: true"
        match = True   
    Else
        Label3.Text = "mouse drag over:"
        Label4.Text = "word drag state: false"
        Me.RichTextBox1.Select(0, 0)
    End If
End Sub

Upvotes: 0

Benjli
Benjli

Reputation: 125

That is a code for highlighting selected text at yellow (can be replaced by any other color), after finding it:

    'find the text that need to be highlighted.
    foundIndex = RichTextBox1.Find("hello", foundIndex + 1, -1, selectedFinds)
    RichTextBox1.Focus()

    If foundIndex = -1 Then
        MessageBox.Show("This document don't contains the text you typed, or any of the text you typed as a whole word or mach case.", "Find Text Error", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)
 else
'now the text will be highlighted.
 RichTextBox1.SelectionBackColor = Color.Yellow
Richtextbox1.focus
    End If

I hope that code will help.

Upvotes: 0

user1938775
user1938775

Reputation:

I got it in a different way:

   While Not RichTextBox1.Text.IndexOf("hello", startIndex) = -1
               selectedIndex= RichTextBox1.SelectionStart
        Try
                RichTextBox1.Select(RichTextBox1.Text.IndexOf("test", startIndex) - 1, 1)
        Catch
        End Try
        If RichTextBox1.SelectedText = " " Or RichTextBox1.SelectedText = Nothing Then
            RichTextBox1.Select(RichTextBox1.Text.IndexOf("hello", startIndex) + "test".Length, 1)
            If RichTextBox1.SelectedText = " " Or RichTextBox1.SelectedText = Nothing Then
                RichTextBox1.Select(RichTextBox1.Text.IndexOf("hello", startIndex), "test".Length)
                RichTextBox1.SelectionColor = Color.Blue
            End If
        End If

        startIndex = RichTextBox1.Text.IndexOf("hello", startIndex) + "hello".Length
        RichTextBox1.SelectionStart = selectedIndex
        RichTextBox1.SelectionLength = 0
        RichTextBox1.SelectionColor = Color.Black
    End While

I don't know if it is the best way, but works.

Upvotes: 3

jAC
jAC

Reputation: 5324

This code should do the work:

Dim searchstring As String = "hello"
' The word you're looking for
Dim count As New List(Of Integer)()
For i As Integer = 0 To richTextBox1.Text.Length - 1
    If richTextBox1.Text.IndexOf(searchstring, i) <> -1 Then
        'If the word is found
            'Add the index to the list
        count.Add(richTextBox1.Text.IndexOf(searchstring, i))
    End If
Next
Try
    For i As Integer = 0 To count.Count - 1

        richTextBox1.[Select](count(i), searchstring.Length)
        richTextBox1.SelectionFont = New Font(richTextBox1.Font, FontStyle.Bold)
        count.RemoveAt(i)
    Next
Catch
End Try
richTextBox1.[Select](richTextBox1.Text.Length, 0)
richTextBox1.SelectionFont = New Font(richTextBox1.Font, FontStyle.Regula

For each index select the text and make it bold.

Now add this code to the TextChanged-Event to check any time the text changed for your word.

Upvotes: 3

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