Adding some parts in a TextBox vb - vb.net

Question

I was wondering if there is a way to allow only some sections of a textbox to be editable in a frozen sentence.
e.g:
He share of ________ to worse. Weddings and any opinions suitable smallest nay.
My he houses or months settle remove ladies appear. Engrossed suffering
supposing he recommend do eagerness.
where the underscore can be edited but the sentences cannot be changed at all.
Thanks

Answer 1

A simple solution for your example
Public Class Form1
Private SelectionStart As Integer = 10
Private SelectionEnd As Integer = 20
Private SelectionCurrent As Integer = 10
Private Sub CursorControl(Optional ByVal e As Object = Nothing)
If SelectionCurrent > SelectionEnd Then
SelectionCurrent = SelectionEnd
ElseIf SelectionCurrent < SelectionStart Then
SelectionCurrent = SelectionStart
End If
If TextBox1.SelectionStart >= SelectionEnd Then
If Not e Is Nothing Then
e.Handled = True
e = Nothing
End If
TextBox1.SelectionStart = SelectionEnd
TextBox1.SelectionLength = 0
Me.SelectionCurrent = TextBox1.SelectionStart
ElseIf TextBox1.SelectionStart <= SelectionStart Then
If Not e Is Nothing Then
e.Handled = True
e = Nothing
End If
TextBox1.SelectionStart = SelectionStart
TextBox1.SelectionLength = 0
Me.SelectionCurrent = TextBox1.SelectionStart
Else
Me.SelectionCurrent = TextBox1.SelectionStart
End If
End Sub
Private Sub TextBox1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Click
CursorControl()
End Sub
Private Sub TextBox1_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.GotFocus
CursorControl()
End Sub
Private Sub TextBox1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
TextBox1.SelectionStart = Me.SelectionCurrent
TextBox1.SelectionLength = 0
If e.KeyCode = Keys.Right Or e.KeyCode = Keys.Left Or e.KeyCode = Keys.Down Or e.KeyCode = Keys.Up Then
e.Handled = True
e = Nothing
End If
CursorControl(e)
End Sub
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
TextBox1.SelectionStart = Me.SelectionCurrent
TextBox1.SelectionLength = 0
If e.KeyChar = "_" Then
e.Handled = True
End If
If TextBox1.SelectionStart >= SelectionEnd Then
e.Handled = True
e = Nothing
ElseIf TextBox1.SelectionStart <= SelectionStart Then
e.Handled = True
e = Nothing
Else
TextBox1.Text = TextBox1.Text.Substring(0, TextBox1.SelectionStart) & e.KeyChar & TextBox1.Text.Substring(TextBox1.SelectionStart + 1, TextBox1.Text.Length - TextBox1.SelectionStart - 1)
TextBox1.SelectionStart = Me.SelectionCurrent
e.Handled = True
e = Nothing
End If
CursorControl()
End Sub
Private Sub TextBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyUp
TextBox1.SelectionStart = Me.SelectionCurrent
TextBox1.SelectionLength = 0
If e.KeyCode = 189 Then '_
e.Handled = True
End If
Me.SelectionCurrent = Me.SelectionCurrent + 1
Me.TextBox1.SelectionStart = Me.SelectionCurrent
CursorControl(e)
End Sub
End Class

Answer 2

Put three TextBoxes next to each other and allow only the middle one to be edited. Here's some XAML:
<StackPanel
Orientation="Horizontal">
<TextBox
Text="He share of"
IsReadOnly=True />
<TextBox
Text="<Enter your phrase here>" />
<TextBox
Text="to worse. ......."
IsReadOnly=True />
</StackPanel>
The end user will see the whole line as one unit.

Answer 3

The Winform control RichTextBox via the SelectionProtected Property allows you to mark text ranges a readonly (protected).
Marking the entire text as protected and then selectively unprotecting the desired editable range will produce the desired effect.
Public Class Form1
Private underlinedFont As Font
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
RichTextBox1.Text = "This is protected. This is unprotected."
' Protect all text
RichTextBox1.SelectAll()
RichTextBox1.SelectionProtected = True
' Unprotect the word "unprotected"
Dim startUnProtected As Int32 = RichTextBox1.Find("unprotected", RichTextBoxFinds.WholeWord)
If startUnProtected > -1 Then
RichTextBox1.SelectionProtected = False
If underlinedFont Is Nothing Then underlinedFont = New Font(RichTextBox1.Font.FontFamily, RichTextBox1.Font.Size, FontStyle.Underline, RichTextBox1.Font.Unit)
RichTextBox1.SelectionFont = underlinedFont
End If
End Sub
End Class