Wpf – Multiline Textbox with automatic vertical scroll

autoscrollmultilinetextboxwpf

There are a lot of similiar questions over internet, on SO included, but proposed solutions doesn't work in my case.
Scenario : there is a log textbox in xaml

 <TextBox Name="Status"
          Margin="5"
          Grid.Column="1"
          Grid.Row="5"
          HorizontalAlignment="Left"
          VerticalAlignment="Top"
          Width="600"
          Height="310"/>

There are methods in code-behind that do some work and add some multiline (maybe that's the problem?) messages into this textbox:

private static void DoSomeThings(TextBox textBox)
{
   // do work
   textBox.AppendText("Work finished\r\n"); // better way than Text += according to msdn
   // do more
   textBox.AppendText("One more message\r\n");
   ...
}

private static void DoSomething2(TextBox textBox)
{
   // same as first method
}

Need to scroll to bottom of textbox after all actions take place. Tried ScrollToEnd(), ScrollToLine, wrapping textbox into ScrollViewer, Selection and Caret workarounds, attaching ScrollToEnd to TextChanged. None of this works, after execution lines that overflow textbox height still need to be scrolled to manually. Sorry for duplicate question, i guess i'm missing some minor issues that can be resolved quickly by someone that has fresh vision on the problem. Thanks in advance.

Best Answer

According to this question: TextBox.ScrollToEnd doesn't work when the TextBox is in a non-active tab

You have to focus the text box, update the caret position and then scroll to end:

Status.Focus();
Status.CaretIndex = Status.Text.Length;
Status.ScrollToEnd();

EDIT

Example TextBox:

<TextBox TextWrapping="Wrap" VerticalScrollBarVisibility="Auto" 
         AcceptsReturn="True" Name="textBox"/>

Related Solutions

C# – How to make a textbox that only accepts numbers

Two options:

Use a NumericUpDown instead. NumericUpDown does the filtering for you, which is nice. Of course it also gives your users the ability to hit the up and down arrows on the keyboard to increment and decrement the current value.

Handle the appropriate keyboard events to prevent anything but numeric input. I've had success with this two event handlers on a standard TextBox:

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) &&
        (e.KeyChar != '.'))
    {
            e.Handled = true;
    }

    // only allow one decimal point
    if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1))
    {
        e.Handled = true;
    }
}

You can remove the check for '.' (and the subsequent check for more than one '.') if your TextBox shouldn't allow decimal places. You could also add a check for '-' if your TextBox should allow negative values.

If you want to limit the user for number of digit, use: textBox1.MaxLength = 2; // this will allow the user to enter only 2 digits

Javascript – Creating multiline strings in JavaScript

Update:

ECMAScript 6 (ES6) introduces a new type of literal, namely template literals. They have many features, variable interpolation among others, but most importantly for this question, they can be multiline.

A template literal is delimited by backticks:

var html = `
  <div>
    <span>Some HTML here</span>
  </div>
`;

(Note: I'm not advocating to use HTML in strings)

Browser support is OK, but you can use transpilers to be more compatible.

Original ES5 answer:

Javascript doesn't have a here-document syntax. You can escape the literal newline, however, which comes close:

"foo \
bar"

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