I'm using Windows forms and I have a textbox which I would occassionally like to make the text bold if it is a certain value.
How do I change the font characteristics at run time?
I see that there is a property called textbox1.Font.Bold but this is a Get only property.
You could use Extension
method to switch between Regular Style and Bold Style as below:
static class Helper
{
public static void SwtichToBoldRegular(this TextBox c)
{
if (c.Font.Style!= FontStyle.Bold)
c.Font = new Font(c.Font, FontStyle.Bold);
else
c.Font = new Font(c.Font, FontStyle.Regular);
}
}
And usage:
textBox1.SwtichToBoldRegular();
txtText.Font = new Font("Segoe UI", 8,FontStyle.Bold);
//Font(Font Name,Font Size,Font.Style)
Depending on your application, you'll probably want to use that Font assignment either on text change or focus/unfocus of the textbox in question.
Here's a quick sample of what it could look like (empty form, with just a textbox. Font turns bold when the text reads 'bold', case-insensitive):
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
RegisterEvents();
}
private void RegisterEvents()
{
_tboTest.TextChanged += new EventHandler(TboTest_TextChanged);
}
private void TboTest_TextChanged(object sender, EventArgs e)
{
// Change the text to bold on specified condition
if (_tboTest.Text.Equals("Bold", StringComparison.OrdinalIgnoreCase))
{
_tboTest.Font = new Font(_tboTest.Font, FontStyle.Bold);
}
else
{
_tboTest.Font = new Font(_tboTest.Font, FontStyle.Regular);
}
}
}
Here is an example for toggling bold, underline, and italics.
protected override bool ProcessCmdKey( ref Message msg, Keys keyData )
{
if ( ActiveControl is RichTextBox r )
{
if ( keyData == ( Keys.Control | Keys.B ) )
{
r.SelectionFont = new Font( r.SelectionFont, r.SelectionFont.Style ^ FontStyle.Bold ); // XOR will toggle
return true;
}
if ( keyData == ( Keys.Control | Keys.U ) )
{
r.SelectionFont = new Font( r.SelectionFont, r.SelectionFont.Style ^ FontStyle.Underline ); // XOR will toggle
return true;
}
if ( keyData == ( Keys.Control | Keys.I ) )
{
r.SelectionFont = new Font( r.SelectionFont, r.SelectionFont.Style ^ FontStyle.Italic ); // XOR will toggle
return true;
}
}
return base.ProcessCmdKey( ref msg, keyData );
}
Source: Stackoverflow.com