Make your C# form go fullscreen

Many applications have the ability to go fullscreen. Here’s a simple snippet which will make your form go fullscreen and restore to its original location.

For testing purposes, I’ve attached a very simple KeyDown event which checks for F11 keypresses (the standard fullscreen keyboard shortcut in many applications).

[csharp]using System.Drawing;
using System.Windows.Forms;

namespace Danny_GB_Net {
public partial class FullscreenForm : Form {
// struct containing key information needed to restore the form to its original size/state
struct FullscreenRestoreState {
public Point location;
public int width;
public int height;
public FormWindowState state;
public FormBorderStyle style;
FullscreenRestoreState restoreState;

// used in ToggleFullscreen so that the program knows whether it needs to go fullscreen or restore
bool isFullscreen = false;

// standard constructor
public FullscreenForm() {

// attach a test event
KeyDown += new System.Windows.Forms.KeyEventHandler(KeyDownEventHandler);

void ToggleFullscreen() {
if (!isFullscreen) { // save state information to restoreState and go fullscreen
restoreState.location = Location;
restoreState.width = Width;
restoreState.height = Height;
restoreState.state = WindowState; = FormBorderStyle;

TopMost = true;
Location = new Point(0, 0);
FormBorderStyle = FormBorderStyle.None;
Width = Screen.PrimaryScreen.Bounds.Width;
Height = Screen.PrimaryScreen.Bounds.Height;
} else { // restore from restoreState
TopMost = false;
Location = restoreState.location;
Width = restoreState.width;
Height = restoreState.height;
WindowState = restoreState.state;
FormBorderStyle =;

// toggle our variable
isFullscreen = !isFullscreen;

// event for testing purposes
private void KeyDownEventHandler(object sender, KeyEventArgs e) {
if (e.KeyCode == Keys.F11) {