I've got an always on-top application (basically a status display) that I want to follow around another program and always sit just to the left of the minimize button.
I can get the Rect representing the "target" process using the following code which I can then pair with an offset to generate the initial position of my overlay.
Get the HWnd IntPtr:
private IntPtr HWnd = Process.GetProcessesByName("targetapplication")[0].MainWindowHandle;
Declare the function from user32.dll:
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect);
And the appropriate struct:
[StructLayout(LayoutKind.Sequential)]
private struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
}
And then call it on demand.
However, I would like to avoid constantly polling this value, so I would like to hook into the target application and respond whenever the target window is moved.
Looking around the user32.dll documentation, the only way I can see for doing this is using SetWindowsHookEx(). I'm not entirely sure of how I'd go about intercepting an event from here however.
I believe the target application is built off of WinForms but I cannot be sure. So solutions that let me respond to the target's Move event or directly to some Windows Message would both be useful.
Any ideas on how I can proceed?
A method to hook a Windows Form to another process (Notepad, in this case) and follow the movements of the process' Main Window, to create sort of a Toolbar that can interact with the process, using SetWinEventHook().
To get the hooked Window bounds, GetWindowRect() is not recommended. Better call DwmGetWindowAttribute() passing DWMWA_EXTENDED_FRAME_BOUNDS as the DWMWINDOWATTRIBUTE, which still returns a RECT. This because GetWindowRect() is not DpiAware and it may return a virtualized measure in some contexts, plus it includes the Window drop shadow in specific configurations.
Read more about DpiAwarenes, Screen layout and VirtualScreen here:
Using SetWindowPos with multiple monitors
Also refactored the Hook helper class and the NativeMethods declarations.
▶ To move to foreground the Tool Window, as in the animation, when the hooked Window becomes the Foreground Window, also hook the EVENT_SYSTEM_FOREGROUND event: you'll receive a notification when the Foreground Window changes, then compare with the handle of Window you're hooking.
A visual representation of the results:
The Form class initialization procedure:
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Windows.Forms;
public partial class Form1 : Form
{
private IntPtr notepadhWnd;
private IntPtr hWinEventHook;
private Process targetProc = null;
protected Hook.WinEventDelegate WinEventDelegate;
static GCHandle GCSafetyHandle;
public Form1()
{
InitializeComponent();
WinEventDelegate = new Hook.WinEventDelegate(WinEventCallback);
GCSafetyHandle = GCHandle.Alloc(WinEventDelegate);
targetProc = Process.GetProcessesByName("notepad").FirstOrDefault(p => p != null);
try {
if (targetProc != null) {
notepadhWnd = targetProc.MainWindowHandle;
if (notepadhWnd != IntPtr.Zero) {
uint targetThreadId = Hook.GetWindowThread(notepadhWnd);
hWinEventHook = Hook.WinEventHookOne(
NativeMethods.SWEH_Events.EVENT_OBJECT_LOCATIONCHANGE,
WinEventDelegate, (uint)targetProc.Id, targetThreadId);
var rect = Hook.GetWindowRectangle(notepadhWnd);
// Of course, set the Form.StartPosition to Manual
Location = new Point(rect.Right, rect.Top);
}
}
}
catch (Exception ex) {
// Log and message or
throw;
}
}
protected void WinEventCallback(
IntPtr hWinEventHook,
NativeMethods.SWEH_Events eventType,
IntPtr hWnd,
NativeMethods.SWEH_ObjectId idObject,
long idChild, uint dwEventThread, uint dwmsEventTime)
{
if (hWnd == notepadhWnd &&
eventType == NativeMethods.SWEH_Events.EVENT_OBJECT_LOCATIONCHANGE &&
idObject == (NativeMethods.SWEH_ObjectId)NativeMethods.SWEH_CHILDID_SELF)
{
var rect = Hook.GetWindowRectangle(hWnd);
Location = new Point(rect.Right, rect.Top);
}
}
protected override void OnFormClosing(FormClosingEventArgs e)
{
base.OnFormClosing(e);
if (!e.Cancel) {
if (GCSafetyHandle.IsAllocated) GCSafetyHandle.Free();
Hook.WinEventUnhook(hWinEventHook);
}
}
protected override void OnShown(EventArgs e)
{
if (targetProc == null) {
this.Hide();
MessageBox.Show("Notepad not found!", "Target Missing", MessageBoxButtons.OK, MessageBoxIcon.Hand);
this.Close();
}
else {
Size = new Size(50, 140);
targetProc.Dispose();
}
base.OnShown(e);
}
The support classes used to reference the Windows API methods:
using System.Runtime.InteropServices;
using System.Security.Permissions;
public class Hook
{
public delegate void WinEventDelegate(
IntPtr hWinEventHook,
NativeMethods.SWEH_Events eventType,
IntPtr hwnd,
NativeMethods.SWEH_ObjectId idObject,
long idChild,
uint dwEventThread,
uint dwmsEventTime
);
public static IntPtr WinEventHookRange(
NativeMethods.SWEH_Events eventFrom, NativeMethods.SWEH_Events eventTo,
WinEventDelegate eventDelegate,
uint idProcess, uint idThread)
{
return NativeMethods.SetWinEventHook(
eventFrom, eventTo,
IntPtr.Zero, eventDelegate,
idProcess, idThread,
NativeMethods.WinEventHookInternalFlags);
}
public static IntPtr WinEventHookOne(
NativeMethods.SWEH_Events eventId,
WinEventDelegate eventDelegate,
uint idProcess,
uint idThread)
{
return NativeMethods.SetWinEventHook(
eventId, eventId,
IntPtr.Zero, eventDelegate,
idProcess, idThread,
NativeMethods.WinEventHookInternalFlags);
}
public static bool WinEventUnhook(IntPtr hWinEventHook) =>
NativeMethods.UnhookWinEvent(hWinEventHook);
public static uint GetWindowThread(IntPtr hWnd)
{
return NativeMethods.GetWindowThreadProcessId(hWnd, IntPtr.Zero);
}
public static NativeMethods.RECT GetWindowRectangle(IntPtr hWnd)
{
NativeMethods.DwmGetWindowAttribute(hWnd,
NativeMethods.DWMWINDOWATTRIBUTE.DWMWA_EXTENDED_FRAME_BOUNDS,
out NativeMethods.RECT rect, Marshal.SizeOf<NativeMethods.RECT>());
return rect;
}
}
public static class NativeMethods
{
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
public Rectangle ToRectangle() => Rectangle.FromLTRB(Left, Top, Right, Bottom);
}
public static long SWEH_CHILDID_SELF = 0;
//SetWinEventHook() flags
public enum SWEH_dwFlags : uint
{
WINEVENT_OUTOFCONTEXT = 0x0000, // Events are ASYNC
WINEVENT_SKIPOWNTHREAD = 0x0001, // Don't call back for events on installer's thread
WINEVENT_SKIPOWNPROCESS = 0x0002, // Don't call back for events on installer's process
WINEVENT_INCONTEXT = 0x0004 // Events are SYNC, this causes your dll to be injected into every process
}
//SetWinEventHook() events
public enum SWEH_Events : uint
{
EVENT_MIN = 0x00000001,
EVENT_MAX = 0x7FFFFFFF,
EVENT_SYSTEM_SOUND = 0x0001,
EVENT_SYSTEM_ALERT = 0x0002,
EVENT_SYSTEM_FOREGROUND = 0x0003,
EVENT_SYSTEM_MENUSTART = 0x0004,
EVENT_SYSTEM_MENUEND = 0x0005,
EVENT_SYSTEM_MENUPOPUPSTART = 0x0006,
EVENT_SYSTEM_MENUPOPUPEND = 0x0007,
EVENT_SYSTEM_CAPTURESTART = 0x0008,
EVENT_SYSTEM_CAPTUREEND = 0x0009,
EVENT_SYSTEM_MOVESIZESTART = 0x000A,
EVENT_SYSTEM_MOVESIZEEND = 0x000B,
EVENT_SYSTEM_CONTEXTHELPSTART = 0x000C,
EVENT_SYSTEM_CONTEXTHELPEND = 0x000D,
EVENT_SYSTEM_DRAGDROPSTART = 0x000E,
EVENT_SYSTEM_DRAGDROPEND = 0x000F,
EVENT_SYSTEM_DIALOGSTART = 0x0010,
EVENT_SYSTEM_DIALOGEND = 0x0011,
EVENT_SYSTEM_SCROLLINGSTART = 0x0012,
EVENT_SYSTEM_SCROLLINGEND = 0x0013,
EVENT_SYSTEM_SWITCHSTART = 0x0014,
EVENT_SYSTEM_SWITCHEND = 0x0015,
EVENT_SYSTEM_MINIMIZESTART = 0x0016,
EVENT_SYSTEM_MINIMIZEEND = 0x0017,
EVENT_SYSTEM_DESKTOPSWITCH = 0x0020,
EVENT_SYSTEM_END = 0x00FF,
EVENT_OEM_DEFINED_START = 0x0101,
EVENT_OEM_DEFINED_END = 0x01FF,
EVENT_UIA_EVENTID_START = 0x4E00,
EVENT_UIA_EVENTID_END = 0x4EFF,
EVENT_UIA_PROPID_START = 0x7500,
EVENT_UIA_PROPID_END = 0x75FF,
EVENT_CONSOLE_CARET = 0x4001,
EVENT_CONSOLE_UPDATE_REGION = 0x4002,
EVENT_CONSOLE_UPDATE_SIMPLE = 0x4003,
EVENT_CONSOLE_UPDATE_SCROLL = 0x4004,
EVENT_CONSOLE_LAYOUT = 0x4005,
EVENT_CONSOLE_START_APPLICATION = 0x4006,
EVENT_CONSOLE_END_APPLICATION = 0x4007,
EVENT_CONSOLE_END = 0x40FF,
EVENT_OBJECT_CREATE = 0x8000, // hwnd ID idChild is created item
EVENT_OBJECT_DESTROY = 0x8001, // hwnd ID idChild is destroyed item
EVENT_OBJECT_SHOW = 0x8002, // hwnd ID idChild is shown item
EVENT_OBJECT_HIDE = 0x8003, // hwnd ID idChild is hidden item
EVENT_OBJECT_REORDER = 0x8004, // hwnd ID idChild is parent of zordering children
EVENT_OBJECT_FOCUS = 0x8005, // hwnd ID idChild is focused item
EVENT_OBJECT_SELECTION = 0x8006, // hwnd ID idChild is selected item (if only one), or idChild is OBJID_WINDOW if complex
EVENT_OBJECT_SELECTIONADD = 0x8007, // hwnd ID idChild is item added
EVENT_OBJECT_SELECTIONREMOVE = 0x8008, // hwnd ID idChild is item removed
EVENT_OBJECT_SELECTIONWITHIN = 0x8009, // hwnd ID idChild is parent of changed selected items
EVENT_OBJECT_STATECHANGE = 0x800A, // hwnd ID idChild is item w/ state change
EVENT_OBJECT_LOCATIONCHANGE = 0x800B, // hwnd ID idChild is moved/sized item
EVENT_OBJECT_NAMECHANGE = 0x800C, // hwnd ID idChild is item w/ name change
EVENT_OBJECT_DESCRIPTIONCHANGE = 0x800D, // hwnd ID idChild is item w/ desc change
EVENT_OBJECT_VALUECHANGE = 0x800E, // hwnd ID idChild is item w/ value change
EVENT_OBJECT_PARENTCHANGE = 0x800F, // hwnd ID idChild is item w/ new parent
EVENT_OBJECT_HELPCHANGE = 0x8010, // hwnd ID idChild is item w/ help change
EVENT_OBJECT_DEFACTIONCHANGE = 0x8011, // hwnd ID idChild is item w/ def action change
EVENT_OBJECT_ACCELERATORCHANGE = 0x8012, // hwnd ID idChild is item w/ keybd accel change
EVENT_OBJECT_INVOKED = 0x8013, // hwnd ID idChild is item invoked
EVENT_OBJECT_TEXTSELECTIONCHANGED = 0x8014, // hwnd ID idChild is item w? test selection change
EVENT_OBJECT_CONTENTSCROLLED = 0x8015,
EVENT_SYSTEM_ARRANGMENTPREVIEW = 0x8016,
EVENT_OBJECT_END = 0x80FF,
EVENT_AIA_START = 0xA000,
EVENT_AIA_END = 0xAFFF
}
//SetWinEventHook() Object Ids
public enum SWEH_ObjectId : long
{
OBJID_WINDOW = 0x00000000,
OBJID_SYSMENU = 0xFFFFFFFF,
OBJID_TITLEBAR = 0xFFFFFFFE,
OBJID_MENU = 0xFFFFFFFD,
OBJID_CLIENT = 0xFFFFFFFC,
OBJID_VSCROLL = 0xFFFFFFFB,
OBJID_HSCROLL = 0xFFFFFFFA,
OBJID_SIZEGRIP = 0xFFFFFFF9,
OBJID_CARET = 0xFFFFFFF8,
OBJID_CURSOR = 0xFFFFFFF7,
OBJID_ALERT = 0xFFFFFFF6,
OBJID_SOUND = 0xFFFFFFF5,
OBJID_QUERYCLASSNAMEIDX = 0xFFFFFFF4,
OBJID_NATIVEOM = 0xFFFFFFF0
}
public enum DWMWINDOWATTRIBUTE : uint
{
DWMWA_NCRENDERING_ENABLED = 1, // [get] Is non-client rendering enabled/disabled
DWMWA_NCRENDERING_POLICY, // [set] DWMNCRENDERINGPOLICY - Non-client rendering policy - Enable or disable non-client rendering
DWMWA_TRANSITIONS_FORCEDISABLED, // [set] Potentially enable/forcibly disable transitions
DWMWA_ALLOW_NCPAINT, // [set] Allow contents rendered In the non-client area To be visible On the DWM-drawn frame.
DWMWA_CAPTION_BUTTON_BOUNDS, // [get] Bounds Of the caption button area In window-relative space.
DWMWA_NONCLIENT_RTL_LAYOUT, // [set] Is non-client content RTL mirrored
DWMWA_FORCE_ICONIC_REPRESENTATION, // [set] Force this window To display iconic thumbnails.
DWMWA_FLIP3D_POLICY, // [set] Designates how Flip3D will treat the window.
DWMWA_EXTENDED_FRAME_BOUNDS, // [get] Gets the extended frame bounds rectangle In screen space
DWMWA_HAS_ICONIC_BITMAP, // [set] Indicates an available bitmap When there Is no better thumbnail representation.
DWMWA_DISALLOW_PEEK, // [set] Don't invoke Peek on the window.
DWMWA_EXCLUDED_FROM_PEEK, // [set] LivePreview exclusion information
DWMWA_CLOAK, // [set] Cloak Or uncloak the window
DWMWA_CLOAKED, // [get] Gets the cloaked state Of the window. Returns a DWMCLOACKEDREASON object
DWMWA_FREEZE_REPRESENTATION, // [set] BOOL, Force this window To freeze the thumbnail without live update
PlaceHolder1,
PlaceHolder2,
PlaceHolder3,
DWMWA_ACCENTPOLICY = 19
}
public static SWEH_dwFlags WinEventHookInternalFlags =
SWEH_dwFlags.WINEVENT_OUTOFCONTEXT |
SWEH_dwFlags.WINEVENT_SKIPOWNPROCESS |
SWEH_dwFlags.WINEVENT_SKIPOWNTHREAD;
[DllImport("dwmapi.dll", SetLastError = true)]
internal static extern int DwmGetWindowAttribute(IntPtr hwnd, DWMWINDOWATTRIBUTE dwAttribute, out RECT pvAttribute, int cbAttribute);
[DllImport("user32.dll", SetLastError = true)]
internal static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);
[DllImport("user32.dll")]
internal static extern uint GetWindowThreadProcessId(IntPtr hWnd, IntPtr voidProcessId);
[DllImport("user32.dll", SetLastError = false)]
internal static extern IntPtr SetWinEventHook(
SWEH_Events eventMin,
SWEH_Events eventMax,
IntPtr hmodWinEventProc,
Hook.WinEventDelegate lpfnWinEventProc,
uint idProcess, uint idThread,
SWEH_dwFlags dwFlags);
[DllImport("user32.dll", SetLastError = false)]
internal static extern bool UnhookWinEvent(IntPtr hWinEventHook);
}
Thanks to #Jimi for his help here. The following method worked.
First, store a reference to the target process:
Process _target = Process.GetProcessesByName("target")[0];
Then get the handle to the main window:
IntPtr _tagetHWnd = _target.MainWindowHandle;
Then initialise the hook:
SetWinEventHook(EVENT_OBJECT_LOCATIONCHANGE, EVENT_OBJECT_LOCATIONCHANGE, IntPtr.Zero, TargetMoved, (uint)_foxview.Id,
GetWindowThreadProcessId(_foxview.MainWindowHandle, IntPtr.Zero), WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNPROCESS | WINEVENT_SKIPOWNTHREAD);
Where SetWinEventHook is declared as such:
[DllImport("user32.dll")]
private static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr hmodWinEventProc, WinEventDelegate lpfnWinEventProc, uint idProcess, uint idThread, uint dwFlags);
And the constants involved are:
private const uint EVENT_OBJECT_LOCATIONCHANGE = 0x800B;
private const int HT_CAPTION = 0x2;
private const uint WINEVENT_OUTOFCONTEXT = 0x0000;
private const uint WINEVENT_SKIPOWNPROCESS = 0x0002;
private const uint WINEVENT_SKIPOWNTHREAD = 0x0001;
private const int WM_NCLBUTTONDOWN = 0xA1;
Then in my TargetMoved method I get check the new Window location and move my overlay.
private void TargetMoved(IntPtr hWinEventHook, uint eventType, IntPtr lParam, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime)
{
Rect newLocation = new Rect();
GetWindowRect(_foxViewHWnd, ref newLocation);
Location = new Point(newLocation.Right - (250 + _currentUser.Length * 7), newLocation.Top + 5);
}
Where GetWindowRect() is defined by:
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool GetWindowRect(IntPtr hWnd, ref Rect lpRect);
And Rect is defined by:
[StructLayout(LayoutKind.Sequential)]
private struct Rect
{
public readonly int Left;
public readonly int Top;
public readonly int Right;
public readonly int Bottom;
}
So when you put it all together, the entire class now looks like this:
using System;
using System.Diagnostics;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using UserMonitor;
namespace OnScreenOverlay
{
public partial class Overlay : Form
{
#region Public Fields
public const string UserCache = #"redacted";
#endregion Public Fields
#region Private Fields
private const uint EVENT_OBJECT_LOCATIONCHANGE = 0x800B;
private const uint WINEVENT_OUTOFCONTEXT = 0x0000;
private const uint WINEVENT_SKIPOWNPROCESS = 0x0002;
private const uint WINEVENT_SKIPOWNTHREAD = 0x0001;
private readonly Process _foxview;
private readonly IntPtr _foxViewHWnd;
private readonly UserMon _monitor;
private string _currentUser;
#endregion Private Fields
#region Public Constructors
public Overlay()
{
InitializeComponent();
_target= Process.GetProcessesByName("target")[0];
if (_foxview == null)
{
MessageBox.Show("No target detected... Closing");
Close();
}
_targetHWnd = _target.MainWindowHandle;
InitializeWinHook();
StartPosition = FormStartPosition.Manual;
Location = new Point(Screen.PrimaryScreen.Bounds.Left + 20, Screen.PrimaryScreen.Bounds.Bottom - 20);
ShowInTaskbar = false;
_monitor = new UserMon(UserCache);
_monitor.UserChanged += (s, a) =>
{
_currentUser = a.Value;
if (pictBox.InvokeRequired)
{
pictBox.Invoke((MethodInvoker)delegate { pictBox.Refresh(); });
}
};
_currentUser = _monitor.GetUser();
}
#endregion Public Constructors
#region Private Delegates
private delegate void WinEventDelegate(IntPtr hWinEventHook, uint eventType,
IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime);
#endregion Private Delegates
#region Private Methods
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool GetWindowRect(IntPtr hWnd, ref Rect lpRect);
[DllImport("user32.dll", SetLastError = true)]
private static extern uint GetWindowThreadProcessId(IntPtr hWnd, IntPtr processId);
[DllImport("user32.dll")]
private static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr
hmodWinEventProc, WinEventDelegate lpfnWinEventProc, uint idProcess,
uint idThread, uint dwFlags);
private void InitializeWinHook()
{
SetWinEventHook(EVENT_OBJECT_LOCATIONCHANGE, EVENT_OBJECT_LOCATIONCHANGE, IntPtr.Zero, TargetMoved, (uint)_foxview.Id,
GetWindowThreadProcessId(_foxview.MainWindowHandle, IntPtr.Zero), WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNPROCESS | WINEVENT_SKIPOWNTHREAD);
}
private void Overlay_FormClosing(object sender, FormClosingEventArgs e)
{
_monitor.Dispose();
}
private void pictBox_Paint(object sender, PaintEventArgs e)
{
using (Font myFont = new Font("Arial", 8))
{
e.Graphics.DrawString($"User: {_currentUser}", myFont, Brushes.LimeGreen, new Point(2, 2));
}
}
private void TargetMoved(IntPtr hWinEventHook, uint eventType, IntPtr lParam, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime)
{
Rect newLocation = new Rect();
GetWindowRect(_foxViewHWnd, ref newLocation);
Location = new Point(newLocation.Right - (250 + _currentUser.Length * 7), newLocation.Top + 5);
}
#endregion Private Methods
#region Private Structs
[StructLayout(LayoutKind.Sequential)]
private struct Rect
{
public readonly int Left;
public readonly int Top;
public readonly int Right;
public readonly int Bottom;
}
#endregion Private Structs
}
}
Is there an easy method to restore a minimized form to its previous state, either Normal or Maximized? I'm expecting the same functionality as clicking the taskbar (or right-clicking and choosing restore).
So far, I have this, but if the form was previously maximized, it still comes back as a normal window.
if (docView.WindowState == FormWindowState.Minimized)
docView.WindowState = FormWindowState.Normal;
Do I have to handle the state change in the form to remember the previous state?
I use the following extension method:
using System.Runtime.InteropServices;
namespace System.Windows.Forms
{
public static class Extensions
{
[DllImport( "user32.dll" )]
private static extern int ShowWindow( IntPtr hWnd, uint Msg );
private const uint SW_RESTORE = 0x09;
public static void Restore( this Form form )
{
if (form.WindowState == FormWindowState.Minimized)
{
ShowWindow(form.Handle, SW_RESTORE);
}
}
}
}
Then call form.Restore() in my code.
The easiest way to restore a form to normal state is:
if (MyForm.WindowState == FormWindowState.Minimized)
{
MyForm.WindowState = FormWindowState.Normal;
}
You could simulate clicking on the taskbar button like this:
SendMessage(docView.Handle, WM_SYSCOMMAND, SC_RESTORE, 0);
For me, the code above does NOT work.
But at last I found the working code. Here it is:
CxImports.ManagedWindowPlacement placement = new CxImports.ManagedWindowPlacement();
CxImports.GetWindowPlacement(Convert.ToUInt32(Handle.ToInt64()), placement);
if (placement.flags == CxImports.WPF_RESTORETOMAXIMIZED)
WindowState = FormWindowState.Maximized;
else
WindowState = FormWindowState.Normal;
I guess, you can find all the needed "imported" functions by simple googling.
If anybody wonders how to do that with other apps windows,this code works for me:
public void UnMinimize(IntPtr handle)
{
WINDOWPLACEMENT WinPlacement = new WINDOWPLACEMENT();
GetWindowPlacement(handle, out WinPlacement);
if(WinPlacement.flags.HasFlag(WINDOWPLACEMENT.Flags.WPF_RESTORETOMAXIMIZED))
{
ShowWindow(handle, (int)SW_MAXIMIZE);
}
else
{
ShowWindow(handle, (int)SW_RESTORE);
}
}
Stuff is here:
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public Int32 Left;
public Int32 Top;
public Int32 Right;
public Int32 Bottom;
}
public struct POINT
{
public int x;
public int y;
}
public struct WINDOWPLACEMENT
{
[Flags]
public enum Flags : uint
{
WPF_ASYNCWINDOWPLACEMENT = 0x0004,
WPF_RESTORETOMAXIMIZED = 0x0002,
WPF_SETMINPOSITION = 0x0001
}
/// <summary>
/// The length of the structure, in bytes. Before calling the GetWindowPlacement or SetWindowPlacement functions, set this member to sizeof(WINDOWPLACEMENT).
/// </summary>
public uint length;
/// <summary>
/// The flags that control the position of the minimized window and the method by which the window is restored. This member can be one or more of the following values.
/// </summary>
///
public Flags flags;//uint flags;
/// <summary>
/// The current show state of the window. This member can be one of the following values.
/// </summary>
public uint showCmd;
/// <summary>
/// The coordinates of the window's upper-left corner when the window is minimized.
/// </summary>
public POINT ptMinPosition;
/// <summary>
/// The coordinates of the window's upper-left corner when the window is maximized.
/// </summary>
public POINT ptMaxPosition;
/// <summary>
/// The window's coordinates when the window is in the restored position.
/// </summary>
public RECT rcNormalPosition;
}
public class UnMinimizeClass
{
[DllImport("user32.dll")]
public static extern bool GetWindowPlacement(IntPtr hWnd, out WINDOWPLACEMENT lpwndpl);
[DllImport("user32.dll")]
public static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
const int SW_MAXIMIZE = 3;
const int SW_RESTORE = 9;
public static void UnMinimize(IntPtr handle)
{
WINDOWPLACEMENT WinPlacement = new WINDOWPLACEMENT();
GetWindowPlacement(handle, out WinPlacement);
if (WinPlacement.flags.HasFlag(WINDOWPLACEMENT.Flags.WPF_RESTORETOMAXIMIZED))
{
ShowWindow(handle, SW_MAXIMIZE);
}
else
{
ShowWindow(handle, (int)SW_RESTORE);
}
}
}
Using MainWindow.WindowState = WindowState.Normal; isn't enough
Next approach works for my WPF applcation:
MainWindow.WindowState = WindowState.Normal;
MainWindow.Show();
MainWindow.Activate();
I just added one more piece to generify the solution given by #Mesmo. It will create the instance if not created or restore and focus the form if the instance is already created from anywhere in the application. My requirement was that I didn't want to open multiple forms for some of the functionality in the application.
Utilities Class:
public static class Utilities
{
[DllImport("user32.dll")]
private static extern int ShowWindow(IntPtr hWnd, uint Msg);
private const uint SW_RESTORE = 0x09;
public static void Restore(this Form form)
{
if (form.WindowState == FormWindowState.Minimized)
{
ShowWindow(form.Handle, SW_RESTORE);
}
}
public static void CreateOrRestoreForm<T>() where T: Form
{
Form form = Application.OpenForms.OfType<T>().FirstOrDefault();
if (form == null)
{
form = Activator.CreateInstance<T>();
form.Show();
}
else
{
form.Restore();
form.Focus();
}
}
}
Usage:
Utilities.CreateOrRestoreForm<AboutForm>();
This is simple and works if you don't want to use any PInvoke or API trickery. Keep track of when the form has been resized, ignoring when it is minimised.
FormWindowState _PreviousWindowState;
private void TestForm_Resize(object sender, EventArgs e)
{
if (WindowState != FormWindowState.Minimized)
_PreviousWindowState = WindowState;
}
Later when you want to restore it -- for example if a tray icon is clicked:
private void Tray_MouseClick(object sender, MouseEventArgs e)
{
Activate();
if (WindowState == FormWindowState.Minimized)
WindowState = _PreviousWindowState; // former glory
}
[DllImport("user32.dll")] [return: MarshalAs(UnmanagedType.Bool)] public static extern bool GetWindowRect(IntPtr hWnd, ref wndRect lpRect);
[DllImport("user32.dll")] public static extern bool IsWindowVisible(IntPtr hWnd);
[DllImport("user32.dll")] public static extern bool EnumWindows(WNDENUMPROC lpEnumFunc, int lParam);//用来遍历所有窗口
[DllImport("user32.dll")] public static extern int GetWindowTextW(IntPtr hWnd, [MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpString, int nMaxCount);//获取窗口Text
[DllImport("user32.dll")] public static extern int GetClassNameW(IntPtr hWnd, [MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpString, int nMaxCount);//获取窗口类名
public static List<wndInfo> GetAllDesktopWindows(bool? isVisitable_)
{
//用来保存窗口对象
List<wndInfo> wndList = new List<wndInfo>();
//enum all desktop windows
EnumWindows(delegate (IntPtr hWnd, int lParam)
{
wndInfo wnd = new wndInfo();
StringBuilder sb = new StringBuilder(256);
//get hwnd
wnd.hWnd = hWnd;
if (isVisitable_ == null || IsWindowVisible(wnd.hWnd) == isVisitable_)
{
//get window name
GetWindowTextW(hWnd, sb, sb.Capacity);
wnd.szWindowName = sb.ToString();
//get window class
GetClassNameW(hWnd, sb, sb.Capacity);
wnd.szClassName = sb.ToString();
wndList.Add(wnd);
}
return true;
}, 0);
return wndList;
}
private void Btn_Test5_Click(object sender, RoutedEventArgs e)
{
var ws = WSys.GetAllDesktopWindows(true);
foreach (var w in ws)
{
if (w.szWindowName == "计算器")
{
WSys.ShowWindow(w.hWnd, 5);
WSys.ShowWindow(w.hWnd, 9);
Log.WriteLine(w.szWindowName);
}
}
}
The above code did not quite work for me in all situations
After checking the flags I also have to check showcmd=3 and if so maximise else restore
In Windows Explorer (at least in Win7) when you hover the mouse over a column header, a filter box with an arrow appears that lets you filter the results in the ListView, so for example you can only show files starting with "A" or files > 128 MB. Can this feature be enabled in the basic ListView control in C# without subclassing or modifying the ListView?
Here's some code to play with. Add a new class to your project and paste the code shown below. Compile. Drop the new ListViewEx control from the top of the toolbox onto your form. In the form constructor, call the SetHeaderDropdown() method to enable the button. Implement the HeaderDropdown event to return a control to display. For example:
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
listViewEx1.SetHeaderDropdown(0, true);
listViewEx1.HeaderDropdown += listViewEx1_HeaderDropdown;
}
void listViewEx1_HeaderDropdown(object sender, ListViewEx.HeaderDropdownArgs e) {
e.Control = new UserControl1();
}
}
The below code has a flaw, the popup is displayed in a form. Which can't be too small and takes the focus away from the main form. Check this answer on hints how to implement a control that can be displayed as a toplevel window without needing a form. The code:
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
class ListViewEx : ListView {
public class HeaderDropdownArgs : EventArgs {
public int Column { get; set; }
public Control Control { get; set; }
}
public event EventHandler<HeaderDropdownArgs> HeaderDropdown;
public void SetHeaderDropdown(int column, bool enable) {
if (column < 0 || column >= this.Columns.Count) throw new ArgumentOutOfRangeException("column");
while (HeaderDropdowns.Count < this.Columns.Count) HeaderDropdowns.Add(false);
HeaderDropdowns[column] = enable;
if (this.IsHandleCreated) SetDropdown(column, enable);
}
protected void OnHeaderDropdown(int column) {
var handler = HeaderDropdown;
if (handler == null) return;
var args = new HeaderDropdownArgs() { Column = column };
handler(this, args);
if (args.Control == null) return;
var frm = new Form();
frm.FormBorderStyle = FormBorderStyle.FixedSingle;
frm.ShowInTaskbar = false;
frm.ControlBox = false;
args.Control.Location = Point.Empty;
frm.Controls.Add(args.Control);
frm.Load += delegate { frm.MinimumSize = new Size(1, 1); frm.Size = frm.Controls[0].Size; };
frm.Deactivate += delegate { frm.Dispose(); };
frm.StartPosition = FormStartPosition.Manual;
var rc = GetHeaderRect(column);
frm.Location = this.PointToScreen(new Point(rc.Right - SystemInformation.MenuButtonSize.Width, rc.Bottom));
frm.Show(this.FindForm());
}
protected override void OnHandleCreated(EventArgs e) {
base.OnHandleCreated(e);
if (this.Columns.Count == 0 || Environment.OSVersion.Version.Major < 6 || HeaderDropdowns == null) return;
for (int col = 0; col < HeaderDropdowns.Count; ++col) {
if (HeaderDropdowns[col]) SetDropdown(col, true);
}
}
private Rectangle GetHeaderRect(int column) {
IntPtr hHeader = SendMessage(this.Handle, LVM_GETHEADER, IntPtr.Zero, IntPtr.Zero);
RECT rc;
SendMessage(hHeader, HDM_GETITEMRECT, (IntPtr)column, out rc);
return new Rectangle(rc.left, rc.top, rc.right - rc.left, rc.bottom - rc.top);
}
private void SetDropdown(int column, bool enable) {
LVCOLUMN lvc = new LVCOLUMN();
lvc.mask = LVCF_FMT;
lvc.fmt = enable ? LVCFMT_SPLITBUTTON : 0;
IntPtr res = SendMessage(this.Handle, LVM_SETCOLUMN, (IntPtr)column, ref lvc);
}
protected override void WndProc(ref Message m) {
Console.WriteLine(m);
if (m.Msg == WM_NOTIFY) {
var hdr = (NMHDR)Marshal.PtrToStructure(m.LParam, typeof(NMHDR));
if (hdr.code == LVN_COLUMNDROPDOWN) {
var info = (NMLISTVIEW)Marshal.PtrToStructure(m.LParam, typeof(NMLISTVIEW));
OnHeaderDropdown(info.iSubItem);
return;
}
}
base.WndProc(ref m);
}
private List<bool> HeaderDropdowns = new List<bool>();
// Pinvoke
[DllImport("user32.dll")]
private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, IntPtr lp);
[DllImport("user32.dll")]
private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, ref LVCOLUMN lvc);
[DllImport("user32.dll")]
private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, out RECT rc);
[DllImport("user32.dll")]
private static extern IntPtr SetParent(IntPtr hWnd, IntPtr hParent);
private const int LVM_SETCOLUMN = 0x1000 + 96;
private const int LVCF_FMT = 1;
private const int LVCFMT_SPLITBUTTON = 0x1000000;
private const int WM_NOTIFY = 0x204e;
private const int LVN_COLUMNDROPDOWN = -100 - 64;
private const int LVM_GETHEADER = 0x1000 + 31;
private const int HDM_GETITEMRECT = 0x1200 + 7;
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct LVCOLUMN {
public uint mask;
public int fmt;
public int cx;
public string pszText;
public int cchTextMax;
public int iSubItem;
public int iImage;
public int iOrder;
public int cxMin;
public int cxDefault;
public int cxIdeal;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct POINT {
public int x, y;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct RECT {
public int left, top, right, bottom;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct NMHDR {
public IntPtr hwndFrom;
public IntPtr idFrom;
public int code;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct NMLISTVIEW {
public NMHDR hdr;
public int iItem;
public int iSubItem;
public uint uNewState;
public uint uOldState;
public uint uChanged;
public POINT ptAction;
public IntPtr lParam;
}
}
It might be tricky to implement the same type of interface, but you could have your ListView respond to the contents of a TextBox by handling the TextBox's TextChanged event and filtering the list based on the contents. If you put the list in a DataTable then filtering will be easy and you can repopulate your ListView each time the filter changes.
Of course this depends on how many items are in your list.
When i googled to find the way to change the window style i could find the code in "C" language
How can i use the snippet below in my c# application, so that i can hide the Title Bar of external application ? I have not used "C" before..
//Finds a window by class name
[DllImport("USER32.DLL")]
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
//Sets a window to be a child window of another window
[DllImport("USER32.DLL")]
public static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
//Sets window attributes
[DllImport("USER32.DLL")]
public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
//Gets window attributes
[DllImport("USER32.DLL")]
public static extern int GetWindowLong(IntPtr hWnd, int nIndex);
//assorted constants needed
public static int GWL_STYLE = -16;
public static int WS_CHILD = 0x40000000; //child window
public static int WS_BORDER = 0x00800000; //window with border
public static int WS_DLGFRAME = 0x00400000; //window with double border but no title
public static int WS_CAPTION= WS_BORDER | WS_DLGFRAME; //window with a title bar
/*
This function sets the parent of the window with class
ClassClass to the form/control the method is in.
*/
public void Reparent()
{
//get handle of parent form (.net property)
IntPtr par = this.Handle;
//get handle of child form (win32)
IntPtr child = FindWindow("ClassClass", null);
//set parent of child form
SetParent(child, par);
//get current window style of child form
int style = GetWindowLong(child, GWL_STYLE);
//take current window style and remove WS_CAPTION from it
SetWindowLong(child, GWL_STYLE, (style & ~WS_CAPTION));
}
I'm not a P/Invoke exprert, but looking at: http://www.pinvoke.net/default.aspx/coredll/SetWindowLong.html I guess you can call SetWindowLong to change window style without reparent.
For the window search you can try this:
Process[] processes = Process.GetProcessesByName("notepad.exe");
foreach (Process p in processes)
{
IntPtr pFoundWindow = p.MainWindowHandle;
// now you have the window handle
}
The snippet you have posted is in C#, not in C. You should be able to just add that code to your form and call the Reparent method. (Assuming you are using WinForms)
Note that the Reparent method will not only change the window style, but will also attempt to parent the window as a child of your window.