Change border color in TextBox C#

Question

I have the following code:

public class OurTextBox : TextBox
{
    public OurTextBox()
        : base()
    {
        this.SetStyle(ControlStyles.UserPaint,          


        

Answer 1

There are several ways to do this and none are ideal. This is just the nature of WinForms. However, you have some options. I will summarise:

One way you can achieve what you want is by embedding a TextBox in a Panel as follows.

public class BorderedTextBox : Panel 
{
    private TextBox textBox;
    private bool focusedAlways = false;
    private Color normalBorderColor = Color.Gray;
    private Color focusedBorderColor = Color.Red;

    public BorderTextBox() 
    {
        this.DoubleBuffered = true;
        this.Padding = new Padding(2);

        this.TextBox = new TextBox();
        this.TextBox.AutoSize = false;
        this.TextBox.BorderStyle = BorderStyle.None;
        this.TextBox.Dock = DockStyle.Fill;
        this.TextBox.Enter += new EventHandler(this.TextBox_Refresh);
        this.TextBox.Leave += new EventHandler(this.TextBox_Refresh);
        this.TextBox.Resize += new EventHandler(this.TextBox_Refresh);
        this.Controls.Add(this.TextBox);
    }

    private void TextBox_Refresh(object sender, EventArgs e) 
    {
        this.Invalidate();
    }

    protected override void OnPaint(PaintEventArgs e) 
    {
        e.Graphics.Clear(SystemColors.Window);
        using (Pen borderPen = new Pen(this.TextBox.Focused || FocusedAlways ? 
            focusedBorderColor : normalBorderColor)) 
        {
            e.Graphics.DrawRectangle(borderPen, 
                new Rectangle(0, 0, this.ClientSize.Width - 1, this.ClientSize.Height - 1));
        }
        base.OnPaint(e);
    }

    public TextBox TextBox
    {
        get { return textbox; }
        set { textbox = value; }
    }

    public bool FocusedAlaways
    {
        get { return focusedAlways; }
        set { focusedAlways = value; }
    }
}

You can also do this without overriding any controls, but the above method is better. The above will draw a border when the control gets focus. if you want the border on permanently, set the FocusedAlways property to True.

I hope this helps.