如何更改 WPF 中多行文本框中特定行的文本？

Question

I have a multi-line text box in my WPF project, and I want to change the specified line text. I used to do this easily in Win form, but there is no Lines option in WPF Text box. For example, I used to do this in Windows Form:

Dim lines As String() = VTextBox1.Lines

            lines(Specific Line Number) = "This is a test."

            VTextBox1.Lines = lines

But this piece of cod, not working in WPF textbox.

Do I have any chance that I do this in the WPF textbox?

I have no idea how to do that.

Answer 1

Do it "manually" by manipulating the string yourself:

Dim lines As String() = VTextBox1.Text.Split(vbLf)

Dim lineNumber As Integer = 5
If lines.Length > lineNumber Then
    lines(lineNumber) = "This is a test."
    VTextBox1.Text = String.Join(vbLf, lines)
End If