How do I make a WinForms app go Full Screen

I have a WinForms app that I am trying to make full screen (somewhat like what VS does in full screen mode).

Currently I am setting FormBorderStyle to None and WindowState to Maximized which gives me a little more space, but it doesn't cover over the taskbar if it is visible.

What do I need to do to use that space as well?

For bonus points, is there something I can do to make my MenuStrip autohide to give up that space as well?


To the base question, the following will do the trick (hiding the taskbar)

private void Form1_Load(object sender, EventArgs e)
{
    this.TopMost = true;
    this.FormBorderStyle = FormBorderStyle.None;
    this.WindowState = FormWindowState.Maximized;
}

But, interestingly, if you swap those last two lines the Taskbar remains visible. I think the sequence of these actions will be hard to control with the properties window.


A tested and simple solution

I've been looking for an answer for this question in SO and some other sites, but one gave an answer was very complex to me and some others answers simply doesn't work correctly, so after a lot code testing I solved this puzzle.

Note: I'm using Windows 8 and my taskbar isn't on auto-hide mode.

I discovered that setting the WindowState to Normal before performing any modifications will stop the error with the not covered taskbar.

The code

I created this class that have two methods, the first enters in the "full screen mode" and the second leaves the "full screen mode". So you just need to create an object of this class and pass the Form you want to set full screen as an argument to the EnterFullScreenMode method or to the LeaveFullScreenMode method:

class FullScreen
{
    public void EnterFullScreenMode(Form targetForm)
    {
        targetForm.WindowState = FormWindowState.Normal;
        targetForm.FormBorderStyle = FormBorderStyle.None;
        targetForm.WindowState = FormWindowState.Maximized;
    }

    public void LeaveFullScreenMode(Form targetForm)
    {
        targetForm.FormBorderStyle = System.Windows.Forms.FormBorderStyle.Sizable;
        targetForm.WindowState = FormWindowState.Normal;
    }
}

Usage example

    private void fullScreenToolStripMenuItem_Click(object sender, EventArgs e)
    {
        FullScreen fullScreen = new FullScreen();

        if (fullScreenMode == FullScreenMode.No)  // FullScreenMode is an enum
        {
            fullScreen.EnterFullScreenMode(this);
            fullScreenMode = FullScreenMode.Yes;
        }
        else
        {
            fullScreen.LeaveFullScreenMode(this);
            fullScreenMode = FullScreenMode.No;
        }
    }

I have placed this same answer on another question that I'm not sure if is a duplicate or not of this one. (Link to the other question: How to display a Windows Form in full screen on top of the taskbar?)


And for the menustrip-question, try set

MenuStrip1.Parent = Nothing

when in fullscreen mode, it should then disapear.

And when exiting fullscreenmode, reset the menustrip1.parent to the form again and the menustrip will be normal again.