Remove borders winforms and WindowState Maximized without fullscreen

Question

I have the following trouble and i don't find a solution.

I want to implement a Winform without top bar and if is possible, without borders. I tried several things without success, the following would do the trick perfectly :

        this.Text = string.Empty;
        this.ControlBox = false;
        this.FormBorderStyle = FormBorderStyle.SizableToolWindow;

producing the following result :

The little problem is when me or the user trigger the maximize state , because will make the form enter in a FULLSCREEN mode ! and i don't know how to prevent this:

See? You can't see the windows taskbar ! I'm using

WindowState = FormWindowState.Maximized; // Makes a fullscreen that i dont want !

Appreciate your help !

Answer 1

Well ! Thanks to all your answers I finally solved with the following two methods

    private void MaximizeWindow() 
    {
        var rectangle = Screen.FromControl(this).Bounds;
        this.FormBorderStyle = FormBorderStyle.None;
        Size = new Size(rectangle.Width, rectangle.Height);
        Location = new Point(0, 0);
        Rectangle workingRectangle = Screen.PrimaryScreen.WorkingArea;
        this.Size = new Size(workingRectangle.Width, workingRectangle.Height);
    }

    private void ResizableWindow() 
    {
        this.ControlBox = false;
        this.FormBorderStyle = FormBorderStyle.SizableToolWindow;
    }

Thanks to X-TECH and Luïs , this was solved !

Answer 2

Try this to set size dynamically, it may helps you.

Do not use WindowState = FormWindowState.Maximized; Try this code on loading form

var rectangle = ScreenRectangle();
Size = new Size(rectangle.Width - 100, rectangle.Height - 100);
Location = new Point(50, 50);
// here 100 is pixel used to reserve from edges, 
// you can set lower value according to your requirements

For full size

var rectangle = ScreenRectangle();
Size = new Size(rectangle.Width, rectangle.Height);
Location = new Point(0, 0);

Screen Rectangle Method is:

public Rectangle ScreenRectangle()
{
    return Screen.FromControl(this).Bounds;
}

Answer 3

If you want to take control over form maximization, do it like that:

  public class MyForm {
    protected override void WndProc(ref Message m) {
      const int WM_SYSCOMMAND = 0x0112;
      const int SC_MAXIMIZE = 0xF030;

      // When form is going to be maximized    
      if ((m.Msg == WM_SYSCOMMAND) && (m.WParam.ToInt32() == SC_MAXIMIZE)) {
        m.Msg = 0; // <- we don't want a standard maximization
        //TODO: tell Windows here what to do when user want to maximize the form

        // Just a sample (pseudo maximization)
        Location = new Point(0, 0);
        Size = new Size(Screen.GetWorkingArea(this).Width,
                        Screen.GetWorkingArea(this).Height);
      }

      base.WndProc(ref m);
    } 
    ...
  }