Home

Microsoft Visual C# Controls:
The Panel Control

 

Introduction

The panel is a rectangular object that can provide various valuable services for application design. A panel allows you to design good-looking forms by adjusting colors and other properties. A panel can also be used as control delimiter for objects that behave as a group. An example would be a set of radio buttons.

As a member of the family of control containers, a panel can be used to hold or carry controls placed on it. When a panel moves, it does so with the controls placed on it. When a panel is visible, the controls placed on it can be visible too, unless they have their own visibility removed. When a panel is hidden, its child controls are hidden too, regardless of their own visibility status. This property also applies to the panel's availability.

Panels are not transparent. Therefore, their color can be changed to control their background display. A panel is a complete control with properties, methods, and events.

Creating a Panel

To add a panel to a container, you can click the Panel button Panel from the Toolbox and click the desired location on the container. Unlike the form, during design, a panel must primarily be positioned on another container which would be a form or another panel.

To programmatically create a panel, declare a handle to Panel, allocate memory for it using the new operator, and add it to its parent. Here is an example:

using System;
using System.Drawing;
using System.Windows.Forms;

public class Exercise : System.Windows.Forms.Form
{
    Panel pnlContainer;

    public Exercise()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        Text     = "Domain Configuration";
        Width    = 320;
        Height   = 210;
        Location = System.Drawing.Point(140, 100);
        StartPosition = FormStartPosition.CenterScreen;

        pnlContainer = new Panel();
        pnlContainer.Location = Point(20, 20);
        pnlContainer.Size = System.Drawing.Size(100, 60);
        Controls.Add(pnlContainer);
    }
}

public class Program
{
    static int Main()
    {
        System.Windows.Forms.Application.Run(new Exercise());
        return 0;
    }
}

Characteristics of a Panel

By default, a panel object is drawn without borders. If you want to add borders to it, use the BorderStyle property. It provides three values that you can set in the Properties window: None, FixedSingle, and Fixed3D and their effects are as follows:

  None FixedSingle Fixed3D
Design A panel with a None value as BorderStyle A panel with a FixedSingle value as BorderStyle A panel with a Fixed3Dvalue as BorderStyle
Run

To programmatically specify the border style, assign the desired value to the Panel.BorderStyle property. Here is an example:

private void InitializeComponent()
{
        Text     = "Domain Configuration";
        Width    = 320;
        Height   = 210;
        Location = System.Drawing.Point(140, 100);
        StartPosition = FormStartPosition.CenterScreen;

        pnlContainer = new Panel();
        pnlContainer.Location = Point(20, 20);
        pnlContainer.Size = System.Drawing.Size(100, 60);
        pnlContainer.BorderStyle = BorderStyle.Fixed3D;

        Controls.Add(pnlContainer);
}

A panel can be used as a button, in which case the user would click it to initiate an action.

A property that is highly used on panels (and forms) is the Color. If you change the BackColor property, the new color would cover the face of the panel.

 
 

Home Copyright 2008-2009, yevol.com