Introduction
Ever wanted to completely hide all the crap on your machine that you're not supposed to be looking at when your boss walks by? Try this handy Window Hider utility and all you will have to do is press a customizable hotkey.
This source project will demonstrate the implementation of hot keys, enumerable collections, enums, binary serialization, DllImports of Win32 API, Window Enumeration, CallBacks/Delegates, Custom Events and Event Handlers, and more. It's quite a bit of code to look through but some of you may find it interesting.
The guts of the application is based in the Window and Windows classes that enumerate and hide the open windows your choose:
using System;
using System.Text;
using System.Collections;
using System.Runtime.InteropServices;
namespace WindowHider
{
///
/// Object used to control a Windows Form.
///
public class Window
{
///
/// Win32 API Imports
///
[DllImport("user32.dll")] private static extern
bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")] private static extern
bool SetForegroundWindow(IntPtr hWnd);
[DllImport("user32.dll")] private static extern
bool IsIconic(IntPtr hWnd);
[DllImport("user32.dll")] private static extern
bool IsZoomed(IntPtr hWnd);
[DllImport("user32.dll")] private static extern
IntPtr GetForegroundWindow();
[DllImport("user32.dll")] private static extern
IntPtr GetWindowThreadProcessId(IntPtr hWnd, IntPtr ProcessId);
[DllImport("user32.dll")] private static extern
IntPtr AttachThreadInput(IntPtr idAttach, IntPtr idAttachTo, int fAttach);
///
/// Win32 API Constants for ShowWindowAsync()
///
private const int SW_HIDE = 0;
private const int SW_SHOWNORMAL = 1;
private const int SW_SHOWMINIMIZED = 2;
private const int SW_SHOWMAXIMIZED = 3;
private const int SW_SHOWNOACTIVATE = 4;
private const int SW_RESTORE = 9;
private const int SW_SHOWDEFAULT = 10;
///
/// Private Fields
///
private IntPtr m_hWnd;
private string m_Title;
private bool m_Visible = true;
private string m_Process;
private bool m_WasMax = false;
///
/// Window Object's Public Properties
///
public IntPtr hWnd
{
get{return m_hWnd;}
}
public string Title
{
get{return m_Title;}
}
public string Process
{
get{return m_Process;}
}
///
/// Sets this Window Object's visibility
///
public bool Visible
{
get{return m_Visible;}
set
{
//show the window
if(value == true)
{
if(m_WasMax)
{
if(ShowWindowAsync(m_hWnd,SW_SHOWMAXIMIZED))
m_Visible = true;
}
else
{
if(ShowWindowAsync(m_hWnd,SW_SHOWNORMAL))
m_Visible = true;
}
}
//hide the window
if(value == false)
{
m_WasMax = IsZoomed(m_hWnd);
if(ShowWindowAsync(m_hWnd,SW_HIDE))
m_Visible = false;
}
}
}
///
/// Constructs a Window Object
///
/// Title Caption
/// Handle
/// Owning Process
public Window(string Title, IntPtr hWnd, string Process)
{
m_Title = Title;
m_hWnd = hWnd;
m_Process = Process;
}
//Override ToString()
public override string ToString()
{
//return the title if it has one, if not return the process name
if (m_Title.Length > 0)
{
return m_Title;
}
else
{
return m_Process;
}
}
///
/// Sets focus to this Window Object
///
public void Activate()
{
if(m_hWnd == GetForegroundWindow())
return;
IntPtr ThreadID1 = GetWindowThreadProcessId(GetForegroundWindow(),
IntPtr.Zero);
IntPtr ThreadID2 = GetWindowThreadProcessId(m_hWnd,IntPtr.Zero);
if (ThreadID1 != ThreadID2)
{
AttachThreadInput(ThreadID1,ThreadID2,1);
SetForegroundWindow(m_hWnd);
AttachThreadInput(ThreadID1,ThreadID2,0);
}
else
{
SetForegroundWindow(m_hWnd);
}
if (IsIconic(m_hWnd))
{
ShowWindowAsync(m_hWnd,SW_RESTORE);
}
else
{
ShowWindowAsync(m_hWnd,SW_SHOWNORMAL);
}
}
}
///
/// Collection used to enumerate Window Objects
///
public class Windows : IEnumerable, IEnumerator
{
///
/// Win32 API Imports
///
[DllImport("user32.dll")] private static extern
int GetWindowText(int hWnd, StringBuilder title, int size);
[DllImport("user32.dll")] private static extern
int GetWindowModuleFileName(int hWnd, StringBuilder title, int size);
[DllImport("user32.dll")] private static extern
int EnumWindows(EnumWindowsProc ewp, int lParam);
[DllImport("user32.dll")] private static extern
bool IsWindowVisible(int hWnd);
//delegate used for EnumWindows() callback function
public delegate bool EnumWindowsProc(int hWnd, int lParam);
private int m_Position = -1; // holds current index of wndArray,
// necessary for IEnumerable
ArrayList wndArray = new ArrayList(); //array of windows
//Object's private fields
private bool m_invisible = false;
private bool m_notitle = false;
///
/// Collection Constructor with additional options
///
/// Include invisible Windows
/// Include untitled Windows
public Windows(bool Invisible, bool Untitled)
{
m_invisible = Invisible;
m_notitle = Untitled;
//Declare a callback delegate for EnumWindows() API call
EnumWindowsProc ewp = new EnumWindowsProc(EvalWindow);
//Enumerate all Windows
EnumWindows(ewp, 0);
}
///
/// Collection Constructor
///
public Windows()
{
//Declare a callback delegate for EnumWindows() API call
EnumWindowsProc ewp = new EnumWindowsProc(EvalWindow);
//Enumerate all Windows
EnumWindows(ewp, 0);
}
//EnumWindows CALLBACK function
private bool EvalWindow(int hWnd, int lParam)
{
if (m_invisible == false && !IsWindowVisible(hWnd))
return(true);
StringBuilder title = new StringBuilder(256);
StringBuilder module = new StringBuilder(256);
GetWindowModuleFileName(hWnd, module, 256);
GetWindowText(hWnd, title, 256);
if (m_notitle == false && title.Length == 0)
return(true);
wndArray.Add(new Window(title.ToString(), (IntPtr)hWnd,
module.ToString()));
return(true);
}
//implement IEnumerable
public IEnumerator GetEnumerator()
{
return (IEnumerator)this;
}
//implement IEnumerator
public bool MoveNext()
{
m_Position++;
if (m_Position < wndArray.Count)
{
return true;
}
else
{
return false;
}
}
public void Reset()
{
m_Position = -1;
}
public object Current
{
get
{
return wndArray[m_Position];
}
}
}
}