draw a rectangle around a control that is getting hidden by another control

Yes what you described works unti a control sits over your drawing surface then the line is hidden. Consider this. I have a form with button, textbox, label, treeview, basically a whole bunch of controls randomly arranged on the form. Now How would I draw a diagnol line from the lower left corner to the upper right corner. The line from its start to its end will intersect with the controls. The line is to appear visible and to be in front of all the controls.

Hi Glenn,

I just tried the custom control I posted and added a button, then docked the button to full.  I still see the blue border.

What you want to do in Windows is difficult to accomplish.  (Difficult but not impossible).  You basically want a bitmap to sit over all your controls.  Is that what you are trying to do?

One technique is to create a bitmap with transparent colors (argb, where a is the alpha channel made transparent.  You can overlay the bitmap over the controls. Is this what you are trying to do ?

I think it would help if you described what it is exactly you are trying to accomplish, and perhaps we can suggest something. 

Howdy Mike,

What you've suggested so far is good. I still have one delima. If I site a control on the panel and set the controls dock state to fill is hides the rectangle underneath. I run into this problem all the time and I'm wondering if their is some technique to controlling the display order or z order of the graphics object/rectangle so it will display AKA bring it to the front. So no matter what controls are on top of the panel the rectangle or graphic will display. This way I don't have to go to the trouble of creating a custom control everytime i want o display graphical items on a container.

Heres another example What if I wanted to draw a diagnol line accross the panel. Lets say the panel had a collection of controls, labels, textboxes, etc. sited on it. If i'd draw the line on the panel it would be hidden behind each of these controls. How could I draw it over top?

Thanks

Glenn

The best place to create a graphics object in Windows is always the OnPaint event.  This being the case, what you need to do is create a Custom Control (use the Custom Control Template in Add New Item) and derive from Panel.  In Panel you override OnPaint to add your border.  Here is the code in C# for the custom control you want.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

namespace BlueRectangleApp

public partial class PanelWithBlueBorder : Panel

public PanelWithBlueBorder()

Pen _borderPen = new Pen(Color.Blue, 2);

protected override void OnPaint(PaintEventArgs pe)

// TODO: Add custom paint code here

// Calling the base class OnPaint

base.OnPaint(pe);

Graphics g = pe.Graphics;

g.DrawRectangle(_borderPen, new Rectangle(2, 2, Width-4, Height-4));