How to change the border color of a Groupbox

Question

How to change the border color of a Group-box?

Because I need to put a very light background color...there the edge of the Group-box q I have almost do not appear because they are a very light gray too....

I needed to change to a darker color because I can’t change the background color..

Does anyone have any suggestions???

Answer 1

Create the event below...

private void groupBox1_Paint(object sender, PaintEventArgs e)
    {
        GroupBox box = sender as GroupBox;
        DrawGroupBox(box, e.Graphics, Color.Red, Color.Blue, Collor.Yellow);
    }

And the method responsible for changing the border color and text below...

private void DrawGroupBox(GroupBox box, Graphics g, Color textColor, Color borderColor, Color backgroundColor)
    {
        if (box != null)
        {
            Brush textBrush = new SolidBrush(textColor);
            Brush borderBrush = new SolidBrush(borderColor);
            Pen borderPen = new Pen(borderBrush);
            SizeF strSize = g.MeasureString(box.Text, box.Font);
            Rectangle rect = new Rectangle(box.ClientRectangle.X,
                                           box.ClientRectangle.Y + (int)(strSize.Height / 2),
                                           box.ClientRectangle.Width - 1,
                                           box.ClientRectangle.Height - (int)(strSize.Height / 2) - 1);

            // Coloque a cor do background aqui
            g.Clear(backgroundColor);

            // Draw text
            g.DrawString(box.Text, box.Font, textBrush, box.Padding.Left, 0);

            // Drawing Border
            //Left
            g.DrawLine(borderPen, rect.Location, new Point(rect.X, rect.Y + rect.Height));
            //Right
            g.DrawLine(borderPen, new Point(rect.X + rect.Width, rect.Y), new Point(rect.X + rect.Width, rect.Y + rect.Height));
            //Bottom
            g.DrawLine(borderPen, new Point(rect.X, rect.Y + rect.Height), new Point(rect.X + rect.Width, rect.Y + rect.Height));
            //Top1
            g.DrawLine(borderPen, new Point(rect.X, rect.Y), new Point(rect.X + box.Padding.Left, rect.Y));
            //Top2
            g.DrawLine(borderPen, new Point(rect.X + box.Padding.Left + (int)(strSize.Width), rect.Y), new Point(rect.X + rect.Width, rect.Y));
        }
    }

Change your Groupbox’s Paint event to call groupBox1_Paint.

Answer 2

you need to create a custom control.

Create a Class in your project and use the code below:

public class MyGroupBox : GroupBox
  {
    private Color _borderColor = Color.Black;

    public Color BorderColor
    {
      get { return this._borderColor; }
      set { this._borderColor = value; }
    }

    protected override void OnPaint(PaintEventArgs e)
    {
      //get the text size in groupbox
      Size tSize = TextRenderer.MeasureText(this.Text, this.Font);

      Rectangle borderRect = e.ClipRectangle;
      borderRect.Y = (borderRect.Y + (tSize.Height / 2));
      borderRect.Height = (borderRect.Height - (tSize.Height / 2));
      ControlPaint.DrawBorder(e.Graphics, borderRect, this._borderColor, ButtonBorderStyle.Solid);

      Rectangle textRect = e.ClipRectangle;
      textRect.X = (textRect.X + 6);
      textRect.Width = tSize.Width;
      textRect.Height = tSize.Height;
      e.Graphics.FillRectangle(new SolidBrush(this.BackColor), textRect);
      e.Graphics.DrawString(this.Text, this.Font, new SolidBrush(this.ForeColor), textRect);
    }
  }

After building the project see in your Toolbox the new component created in this example the new control will be Mygroupbox, so you will be able to access the property Bordercolor:

myGroupBox1.BorderColor = Color.Red;