If you have ever wanted a Label or TextBox in Windows Forms that performs a little more like on the web, then you've probably figured out that there's no intuitive way to make a Label or TextBox automatically adjust its height to fit the text it contains. While it may not be intuitive, it's definitely not impossible.

In this example, I'll use a TextBox (you could just as easily use a Label) that is docked to the top of a form.To use this, add aTextBox called MyTextBox to the form, and set Dock to DockStyle.Top. Wire up the Resize event of the TextBox to this event handler. 

private void MyTextBox_Resize( object sender, EventArgs e )
{
    // Grab a reference to the TextBox
    TextBox tb = sender as TextBox; 

    // Figure out how much space is used for borders, etc. 
    int chromeHeight = tb.Height - tb.ClientSize.Height;

    // Create a proposed size that is very tall, but exact in width. 
    Size proposedSize = new Size( tb.ClientSize.Width, int.MaxValue );

    // Measure the text using the TextRenderer
    Size textSize = TextRenderer.MeasureText( tb.Text, tb.Font,
        proposedSize, TextFormatFlags.TextBoxControl
         | TextFormatFlags.WordBreak );

    // Adjust the height to include the text height, chrome height,
    // and vertical margin
    tb.Height = chromeHeight + textSize.Height 
        + tb.Margin.Vertical; 
}

If you want to resize the a Label or TextBox that is not docked (for example, one that is in a FlowLayoutPanel or other Panel, or just placed on the form), then you can handle the Form's Resize even instead, and just modify the Control's properties directly.