讓視窗程式只在 system tray 中顯示, 不會出現在工作列(task bar)中, 也不會出現在 alt-tab 清單裡頭

In system tray, not in task bar

//必須加入一個 notifyIcon 物件, 且將Visible屬性設定為 True
//表單(form)的 WindowStat 設定為 Minimized, ShowInTaskBar 設定為 False

#region 設定為常駐在 tray 中
private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
{
	if (this.WindowState == FormWindowState.Minimized)
	{
		this.WindowState = FormWindowState.Normal;
		this.ShowInTaskbar = true;

		// Activate the form.
		this.Activate();
	}
	else if (this.WindowState == FormWindowState.Normal)
	{
		this.WindowState = FormWindowState.Minimized;
		this.ShowInTaskbar = false;

		notifyIcon1.BalloonTipTitle = "APP Hidden";
		notifyIcon1.BalloonTipText = "Your application has been minimized to the taskbar.";
		notifyIcon1.ShowBalloonTip(3000);
	}
}
#endregion

public Class1()
{
	InitializeComponent();
	this.WindowState = FormWindowState.Minimized;
}

設定成不會在 alt-tab 清單中出現

using System.Runtime.InteropServices;


// 設定成不會在 alt-tab list 中出現
[DllImport("user32.dll")]
public static extern int SetWindowLong(IntPtr window, int index, int value);

[DllImport("user32.dll")]
public static extern int GetWindowLong(IntPtr window, int index);

const int GWL_EXSTYLE = -20;
const int WS_EX_TOOLWINDOW = 0x00000080;
const int WS_EX_APPWINDOW = 0x00040000;

public Class1()
{
	InitializeComponent();
	

	// 設定成不會在 alt-tab list 中出現
	int windowStyle = GetWindowLong(Handle, GWL_EXSTYLE);  
	SetWindowLong(Handle, GWL_EXSTYLE, windowStyle | WS_EX_TOOLWINDOW);
}