c# - Use windows animations on borderless form

Question

Recently I made (mostly out of curiosity) a borderless form. After making my own title bar which includes the title, and the three buttons(minimize, maximize and close), just like every normal Windows program. I also made the code for these buttons (just ask if you want to see the code).

However, I've noticed that there are no animations. What I mean is that, e.g. if I click the minimize button, there is no animation, the program instantly disappears (it doesn't close, the button works, but without an animation). This happens in all cases: When I open the program it instantly appears, when I close it, it instantly disappears.

Is there some sort of way to use these animations that standard Windows programs use?

Answer 1

It doesn't seem possible to have the animation effect on a borderless form. However, there are two possible workarounds.

1. Set the FormBorderStyle back to Sizable just before a Minimize or Restore, and then back to none aftewards.

2. Use the AnimateWindow function instead. The animations tend to happen where the window is currently located. The functions can be applied to any Control, not just top level windows.

Here is some sample code:

    class FormA : Form {

        private const int WM_SYSCOMMAND = 0x0112;
        private const int SC_MINIMIZE = 0xF020;
        private const int SC_RESTORE = 0xF120; 
        protected override void WndProc(ref Message m) {
            switch (m.Msg) {
                case WM_SYSCOMMAND:
                    int command = m.WParam.ToInt32();
                    if (command == SC_RESTORE) {
                        this.FormBorderStyle = FormBorderStyle.Sizable;
                        this.ControlBox = true;
                    }
                break;
            }
            base.WndProc(ref m);
        }
    }

[DllImport("user32.dll")]
static extern bool AnimateWindow(IntPtr hwnd, int dwTime, int dwFlags);

private const int AW_VER_POSITIVE = 0x00000004;
private const int AW_VER_NEGATIVE = 0x00000008;
private const int AW_SLIDE =        0x00040000;
private const int AW_HIDE = 0x00010000;


            [STAThread]
            static void Main() {
                Application.EnableVisualStyles();
                Form f = new FormA();
                f.ControlBox = false;
                f.FormBorderStyle = FormBorderStyle.None;

                bool isMinimizing = false;
                var mb = new Button { Text = "Min" };
                mb.Click += delegate {
                    isMinimizing = true;
                    f.FormBorderStyle = FormBorderStyle.Sizable;
                    f.ControlBox = true;
                    f.WindowState = FormWindowState.Minimized;
                    f.FormBorderStyle = FormBorderStyle.None;
                    isMinimizing = false;
                    //AnimateWindow(f.Handle, 300, AW_SLIDE | AW_VER_POSITIVE | AW_HIDE);

                };
                f.SizeChanged += delegate {
                    if (isMinimizing)
                        return;
                    if (f.WindowState != FormWindowState.Minimized)
                        f.FormBorderStyle = FormBorderStyle.None;
                };

                f.Controls.Add(mb);
                Application.Run(f);
        }