Take a look at this code... also use showintaskbar property of the form
and mark it false when you want it to get off teh task bar - removing an
item from the task bar will remove it from the alt tab list
Here is the code I used to get it to work, it's a little bit bootleg
(with the hasBeenActivated and what not)... but it worked... note: I
didn't add a notification icon, I also didn't do anything on load -
instead i moved everything into activated.:
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Runtime.InteropServices;
namespace WindowsApplication2
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
private bool _hasBeenActivated = false;
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent
call
//
this.Activated += new EventHandler(Form1_Activated);
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 271);
this.Name = "Form1";
this.ShowInTaskbar = false;
this.Text = "Form1";
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
// the function you should call when you want to show or hide
the window
private void ShowHideWindow ()
{
int myVisibleState = this.GetWindowVisibleState(
this.Handle, 0, 0 );
if ( myVisibleState == WIND_VISIBLE )
{
// SW_HIDE = 0;
this.ShowInTaskbar = false;
ShowWindow( this.Handle, 0 );
}
else if ( myVisibleState == WIND_HIDDEN ||
myVisibleState == WIND_COVERED ||
myVisibleState == WIND_PARTIALLY_COVERED )
{
// SW_RESTORE = 9
this.ShowInTaskbar = true;
ShowWindow( this.Handle, 9 );
SetForegroundWindow( this.Handle );
}
}
// the following is the meat of the entire thing
// it does some visibility checks on a pixel matrix regarding your
// app's window - it then decides if the window is hidden
// or not
public const int WIND_HIDDEN = 0;
public const int WIND_VISIBLE = 1;
public const int WIND_COVERED = 21;
public const int WIND_PARTIALLY_COVERED = 3;
internal int GetWindowVisibleState(IntPtr hWnd, int iStepX, int
iStepY)
{
RECT rc = new RECT();
Point pt = new Point();
int i = 0;
int j = 0;
int width = 0;
int height = 0;
int iCountedDots = 0;
int iNotCoveredDots = 0;
IntPtr hAux = IntPtr.Zero;
if ( iStepX <= 0 ) iStepX = 4;
if ( iStepY <= 0 ) iStepY = 16;
if ( !this.Visible || this.WindowState ==
FormWindowState.Minimized )
return WIND_HIDDEN;
else
{
GetWindowRect( hWnd, ref rc );
width = rc.right - rc.left;
height = rc.bottom - rc.top;
for ( i = rc.top; i<rc.bottom; i+=( height/iStepY ) )
{
pt.Y = i;
for ( j=rc.left; j<rc.right; j+= ( width / iStepX ) )
{
pt.X = j;
hAux = WindowFromPoint( pt );
while ( GetParent( hAux ) != IntPtr.Zero )
hAux = GetParent( hAux );
if ( hAux == hWnd ) // another window!
iNotCoveredDots++;
iCountedDots++;
}
}
if ( iNotCoveredDots == iCountedDots ) // window is
completely visible
return WIND_VISIBLE;
else if ( iNotCoveredDots == 0 ) // they're all covered
return WIND_COVERED;
else // partial
return WIND_PARTIALLY_COVERED;
}
}
[DllImport("user32.dll")]
public static extern IntPtr WindowFromPoint(
System.Drawing.Point lpPoint);
[DllImport("user32.dll", ExactSpelling=true, CharSet=CharSet.Auto)]
public static extern IntPtr GetParent(IntPtr hWnd);
[DllImport("User32.dll", CharSet=CharSet.Auto)]
public static extern bool GetWindowRect(IntPtr hWnd, ref RECT
rect);
[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern bool ShowWindow(IntPtr hWnd, short State);
[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern bool SetForegroundWindow(IntPtr hWnd);
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public Int32 left;
public Int32 top;
public Int32 right;
public Int32 bottom;
}
private void Form1_Activated(object sender, EventArgs e)
{
if (! _hasBeenActivated )
{
_hasBeenActivated = true;
ShowWindow( this.Handle, 0 );
}
}
}
}
nv****@hotmail.com wrote:
Ahh thank you. I kinda already knew about the p/invoke method from
http://dotnet247.com/247reference/msgs/45/228585.aspx which is
basically identical to yours but he removes the WS_EX_APPWINDOW tag
while doing the SetWindowLong.
Mainly I was hoping for a managed solution because at
http://pinvoke.net/ under the "GetWindowLong" its like !!Obsolet:
This function is UNSAFE!!
But it seems I can't set the window size to 0,0 (it goes to 2,2
min), and thus now I'm using the p/invoke method and it seems fine
:) Maybe later when a managed solution pop's up I'll be able to
change.
Thanks for your reply.
NvrBst
