I developed an add-on for SAP Business One, as a C# Windows Forms application.
In this add-on, using LoadLibraryEx, I load a native unmanaged DLL (correct me if I'm wrong) written in C++.
The add-on calls a method of the DLL, in this way:
[DllImport("kernel32.dll", SetLastError = true)]
public static extern IntPtr LoadLibraryEx(string lpFileName, IntPtr hReservedNull, LoadLibraryFlags dwFlags);
[DllImport("kernel32.dll", CharSet = CharSet.Ansi)]
public static extern IntPtr GetProcAddress(IntPtr hModule, string lpProcName);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate int _MyDllMethod();
//...
//load library
var handle = LoadLibraryEx(libPath, IntPtr.Zero, 0x00000008 /*LOAD_WITH_ALTERED_SEARCH_PATH*/);
//invoke method
Type delegateFunType = typeof(_MyDllMethod);
IntPtr funAddr = GetProcAddress(handle, delegateFunType.Name);
var fun = Convert.ChangeType(Marshal.GetDelegateForFunctionPointer(funAddr, delegateFunType), delegateFunType);
int result = fun.Invoke(); //now a window appears
This method opens a window with which the user interacts.
Everything working fine, except that such window starts minimized in the task bar, while I need it to appear in the forground as the active window. How can I acieve this?
Finally I found this hack: launching a parallel thread that looks for the window that will be opened by the DLL and bring it to the foreground with Windows API functions:
[DllImport("kernel32.dll", SetLastError = true)]
public static extern IntPtr LoadLibraryEx(string lpFileName, IntPtr hReservedNull, LoadLibraryFlags dwFlags);
[DllImport("kernel32.dll", CharSet = CharSet.Ansi)]
public static extern IntPtr GetProcAddress(IntPtr hModule, string lpProcName);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate int _MyDllMethod();
[DllImport("User32.dll", CharSet = CharSet.Unicode)]
public static extern IntPtr FindWindow(String lpClassName, String lpWindowName);
[DllImport("User32.dll")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
[DllImport("User32.dll")]
private static extern bool ShowWindow(IntPtr handle, int nCmdShow);
[DllImport("User32.dll")]
private static extern bool IsIconic(IntPtr handle);
[DllImport("User32.dll")]
private static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, int dwExtraInfo);
private const int ALT = 0xA4;
private const int EXTENDEDKEY = 0x1;
private const int KEYUP = 0x2;
private const int SW_RESTORE = 9;
//...
//launch a parallel thread that looks for library window
//and brings it to the foreground
ThreadPool.QueueUserWorkItem(delegate {
bool windowFound = false;
int attempts = 0;
while (!windowFound && attempts < 10)
{
attempts++;
//check frequently
Thread.Sleep(200);
//look for the window using its class name
IntPtr handle = FindWindow("DllWindowClassName", null);
//check it is a running process
if (handle != IntPtr.Zero)
{
bool success = false;
//if window is minimized to icon
if (IsIconic(handle))
{
//then show it
success = ShowWindow(handle, SW_RESTORE);
}
//bring window to front
success = SetForegroundWindow(handle);
//once done, this thread can terminate
if (success)
{
windowFound = true;
}
else
{
//in case of failure, try this hack
//simulate a key press and release (hack for SetForegroundWindow to work)
keybd_event((byte)ALT, 0x45, EXTENDEDKEY | 0, 0);
keybd_event((byte)ALT, 0x45, EXTENDEDKEY | KEYUP, 0);
//bring window to front
success = SetForegroundWindow(handle);
//once done, this thread can terminate
if (success)
{
windowFound = true;
}
}
}
}
}, null);
//load library
var handle = LoadLibraryEx(libPath, IntPtr.Zero, 0x00000008 /*LOAD_WITH_ALTERED_SEARCH_PATH*/);
//invoke method
Type delegateFunType = typeof(_MyDllMethod);
IntPtr funAddr = GetProcAddress(handle, delegateFunType.Name);
var fun = Convert.ChangeType(Marshal.GetDelegateForFunctionPointer(funAddr, delegateFunType), delegateFunType);
int result = fun.Invoke(); //now a window appears
You can discover window class name using FindWindow, passing window title, and then with GetClassName. Class name is more reliable than the title, which can change with the language and in the time.
Related
I have a WPF custom virtual keyboard application. I need to host this WPF application as standalone and user should be able to use this to enter values for any window application.
How to get the current focused application window? ex: notepad, notepad++ or any other window applications which takes in input.
I have tried below code to get the current active window, but it returns the WPF virtual keyboard application itself since it is also in active state
var window = System.Windows.Application.Current.Windows.OfType<Window>().SingleOrDefault(w => w.IsActive);
The below code works fine however, this requires windowname as param to set the foregroundwindow
public partial class MainWindow : Window{
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SetForegroundWindow(IntPtr hWnd);
[DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
static extern IntPtr FindWindowByCaption(IntPtr ZeroOnly, string lpWindowName);
private void button1_Click(object sender, RoutedEventArgs e){
SetForegroundWindow(FindWindowByCaption(IntPtr.Zero, "Untitled - Notepad"));
}
}
To get the current active window handle, you could use GetForegroundWindow from the user32.dll.
In C# it should look something like
[DllImport("user32.dll")]
static extern IntPtr GetForegroundWindow();
Or in case your application window will be the active window, you could use GetWindow
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr GetWindow(IntPtr hWnd, GetWindow_Cmd uCmd);
enum GetWindow_Cmd : uint {
GW_HWNDFIRST = 0,
GW_HWNDLAST = 1,
GW_HWNDNEXT = 2,
GW_HWNDPREV = 3,
GW_OWNER = 4,
GW_CHILD = 5,
GW_ENABLEDPOPUP = 6
}
So you could pass your own window handle as first argument and GW_HWNDNEXT as second. As a result you get the handle for the window that is below your current window.
EDIT
As IInspectable mentioned, the above won't work within an WPF application.
But you could try using the following using EnumWindows:
// Get own hWnd
WindowInteropHelper windowHwnd = new(this);
IntPtr ownHwnd = windowHwnd.Handle;
// Find target hWnd
IntPtr targetHWnd = IntPtr.Zero;
NativeMethods.EnumWindows((hWnd, lParam) =>
{
if (hWnd == ownHwnd) { return true; } // Ignore own window
if (!NativeMethods.IsWindowVisible(hWnd)) { return true; } // Ignore hidden windows
if (GetClassName(hWnd).Equals("Shell_TrayWnd", StringComparison.OrdinalIgnoreCase)) { return true; } // Ignore taskbar window
if (string.IsNullOrEmpty(GetWindowTitle(hWnd))) { return true; } // Ignore windows without a title
targetHWnd = hWnd; // Found target hWnd
return false; // Stop iterating
}, IntPtr.Zero);
// Used functions
private string GetWindowTitle(IntPtr hWnd)
{
int textLength = NativeMethods.GetWindowTextLength(hWnd);
StringBuilder sb = new(textLength + 1);
NativeMethods.GetWindowText(hWnd, sb, sb.Capacity);
return sb.ToString();
}
private string GetClassName(IntPtr hWnd)
{
StringBuilder sb = new(256);
NativeMethods.GetClassName(hWnd, sb, sb.Capacity);
return sb.ToString().Trim();
}
internal static class NativeMethods
{
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool IsWindowVisible(IntPtr hWnd);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
internal static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
internal static extern int GetWindowTextLength(IntPtr hWnd);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool EnumWindows(EnumWindowsProc lpEnumFunc, IntPtr lParam);
internal delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
internal static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);
}
Edit 2
To ensure the WPF hWnd is created, you could use WindowInteropHelper.EnsureHandle() method instead of the Handle property. This is important if the WPF window has not been displayed yet.
I need to show Task Manager app programatically, maximize it and minimize it as any other window but there is a problem and it simply doesn't respond to ShowWindow(int hWnd, int nCmdShow).
I am pretty sure I use the correct handle because I enumerated all of the windows with EnumWindows(PCallBack callback, int lParam) and the only window that didn't respond was the task manager window with title process.MainWindowTitle = "Task Manager", I even manually found its handle using spy++ but it still doesn't respond to SW_SHOWNORMAL or any other nCmdShow parameter. I tried running apps as administrator to see if it has something to do with the issue but they kept behaving like normal when proper handle was given to ShowWindow function;
private delegate bool PCallBack(int hWnd, int lParam);
private static void ShowWindows()
{
EnumWindows(new PCallBack(FindWindows), 0);
}
private bool FindWindows(int handle, int lparam)
{
Console.WriteLine("showing");
ShowWindow(handle, (int)SW.SHOWMINIMIZED);
ShowWindow(handle, (int)SW.SHOWNORMAL);
Thread.Sleep(3000);
return true;
}
static void Main(string[] args)
{
ShowWindows();
}
This code literally shows every window EnumWindows can find even if they are not visible and task manager was never shown which proved to me that the problem has nothing to do with wrong handle.
This is how I find it by the way.
// the correct handle of Task Manager window
var handle = (int)Process.GetProcessesByName("taskmgr").FirstOrDefault().MainWindowHandle;
Basically this is my problem. Need help.
it simply doesn't respond to ShowWindow(int hWnd, int nCmdShow).
I tested on Windows 10 and this works for me :
Manifest file with level="requireAdministrator"
Test :
IntPtr hWndTarget = FindWindow("TaskManagerWindow", null);
bool bRet = ShowWindow(hWndTarget, SW_SHOWMINIMIZED);
with declarations :
[DllImport("User32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("User32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
public const int SW_HIDE = 0;
public const int SW_SHOWNORMAL = 1;
public const int SW_SHOWMINIMIZED = 2;
public const int SW_SHOWMAXIMIZED = 3;
How to achieve programmatically that the console window is not resizable.
I don't want user to change the console window size with their mouse.
See the answer in this post on MSDN. It requires p-invoking:
private const int MF_BYCOMMAND = 0x00000000;
public const int SC_CLOSE = 0xF060;
public const int SC_MINIMIZE = 0xF020;
public const int SC_MAXIMIZE = 0xF030;
public const int SC_SIZE = 0xF000;//resize
[DllImport("user32.dll")]
public static extern int DeleteMenu(IntPtr hMenu, int nPosition, int wFlags);
[DllImport("user32.dll")]
private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
[DllImport("kernel32.dll", ExactSpelling = true)]
private static extern IntPtr GetConsoleWindow();
static void Main(string[] args)
{
IntPtr handle = GetConsoleWindow();
IntPtr sysMenu = GetSystemMenu(handle, false);
if (handle != IntPtr.Zero)
{
DeleteMenu(sysMenu, SC_CLOSE, MF_BYCOMMAND);
DeleteMenu(sysMenu, SC_MINIMIZE, MF_BYCOMMAND);
DeleteMenu(sysMenu, SC_MAXIMIZE, MF_BYCOMMAND);
DeleteMenu(sysMenu, SC_SIZE, MF_BYCOMMAND);//resize
}
Console.Read();
}
Note that this does not prevent Windows window snapping (e.g. dragging window to edge of screen, Win+Left and Win+Right)
Since you're trying to disable resizing, I'm guessing you won't want scrollbars either. For that, see this answer to Remove space left after console scrollbars in C# (leftover after matching Console.SetWindowSize and SetBufferSize; also requires p-invoking to "fix").
I'm not sure you can avoid that kind of action.
But you may try to use WindowHeight, WindowWidth, LargestWindowHeight and LargestWindowWidth.
See this:
https://msdn.microsoft.com/pt-br/library/system.console(v=vs.110).aspx
i'm trying to add a new MenuItem using DLL Fucntions imported of the user32.dll using DLLImort to a third party application out of my WPF app.
No I'd like to get the click event of the newly generated MenuItem. Any ideas?
Here's the code so far. I know there are functions of SetWindowHookEx or something else, but I'm stuck.
It's some test code and not bulletproofed..
public partial class MainWindow : Window
{
[DllImport("user32.dll")]
private static extern IntPtr GetMenu(IntPtr hWnd);
[DllImport("user32.dll")]
private static extern IntPtr GetSubMenu(IntPtr hMenu, int nPos);
[DllImport("user32.dll")]
private static extern int GetMenuItemCount(IntPtr hMenu);
[DllImport("user32.dll")]
private static extern bool InsertMenuItem(IntPtr hMenu, uint uItem, bool
fByPosition, [In] ref MENUITEMINFO lpmii);
[DllImport("user32.dll")]
private static extern bool DrawMenuBar(IntPtr hWnd);
internal const UInt32 MIIM_FTYPE = 0x00000100;
internal const UInt32 MF_STRING = 0x00000000;
internal const UInt32 MF_OWNERDRAW = 0x00000100;
const uint MF_POPUP = 0x00000010;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern bool AppendMenu(IntPtr hMenu, MenuFlags uFlags, uint uIDNewItem, string lpNewItem);
[DllImport("user32.dll")]
static extern IntPtr CreatePopupMenu();
[Flags]
public enum MenuFlags : uint
{
MF_STRING = 0,
MF_BYPOSITION = 0x400,
MF_SEPARATOR = 0x800,
MF_REMOVE = 0x1000,
MF_POPUP = 0x00000010,
}
[StructLayout(LayoutKind.Sequential)]
struct MENUITEMINFO
{
public uint cbSize;
public uint fMask;
public uint fType;
public uint fState;
public uint wID;
public IntPtr hSubMenu;
public IntPtr hbmpChecked;
public IntPtr hbmpUnchecked;
public IntPtr dwItemData;
public string dwTypeData;
public uint cch;
public IntPtr hbmpItem;
// return the size of the structure
public static uint sizeOf
{
get { return (uint)Marshal.SizeOf(typeof(MENUITEMINFO)); }
}
}
public MainWindow()
{
InitializeComponent();
Loaded += OnLoaded;
}
private void OnLoaded(object sender, RoutedEventArgs e)
{
createMenuEntry();
}
private void createMenuEntry()
{
Process[] proceses = Process.GetProcessesByName("spotify");
Process process = proceses.Where(e => e.MainWindowTitle == "Spotify").First();
IntPtr handle = process.MainWindowHandle;
IntPtr mainMenu = GetMenu(handle);
int mainMenuItemCount = GetMenuItemCount(mainMenu);
AppendMenu(mainMenu, MenuFlags.MF_STRING, 555, "TestEntry");
}
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
//HwndSource source = PresentationSource.FromVisual(this) as HwndSource;
//source.AddHook(WndProc);
}
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
// Handle messages...
Debug.WriteLine((int)wParam);
if (((int)wParam == 555))
{
MessageBox.Show("Click");
}
return IntPtr.Zero;
}
}
Thanks for any ideas or suggestions in advance.
Your first step is to put down the C# and understand how the native menu API works. Start here: https://msdn.microsoft.com/en-us/library/windows/desktop/ms647553.aspx
I strongly recommend that you create a new C++ project and write a simple program to add a menu and respond to clicks.
The key information is found in the documentation I linked to, with my emphasis:
When the user chooses a command item, the system sends a command message to the window that owns the menu. If the command item is on the window menu, the system sends the WM_SYSCOMMAND message. Otherwise, it sends the WM_COMMAND message.
You need to intercept that message. I suspect that means to need to use a global WH_CALLWNDPROC hook. That's going to need an unmanaged DLL to implement the hook.
I've seen loads of code to launch an external application via a file, but that's not the problem. To clarify exactly the behaviour I want:
For a given filename, launch the correct process.
If there is no associated process, the proper shell dialog should prompt the user to associate one.
While the application is launched, this application needs to go to the back of the Z-order (or just behind the app that is launching) and STAY THERE.
Step 3 is what I haven't got right. I am launching Photoshop via a psd file, but while the aplash screen is shown, it flashes as my app fights for the focus. Once it starts up properly, all is well, but I don't like the flickering while the flash screen is displayed.
Here is my best attempt so far:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Security;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Romy.Core
{
internal static class Example
{
public const int SW_RESTORE = 9;
private static readonly IntPtr HWND_BOTTOM = new IntPtr(1);
private const uint SWP_NOACTIVATE = 0x0010;
private const uint SWP_NOMOVE = 0x0002;
private const uint SWP_NOSIZE = 0x0001;
public static void SendWindowBack(IntPtr handle)
{
NativeMethods.SetWindowPos(handle, HWND_BOTTOM, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_NOACTIVATE);
}
public static async void ShellExecuteFile(this IWin32Window window, string filename)
{
var p = Process.Start(new ProcessStartInfo()
{
FileName = filename,
Verb = "open",
UseShellExecute = true,
ErrorDialog = true
});
SendWindowBack(window.Handle);
try
{
await Task.Run(async () =>
{
try
{
p.WaitForInputIdle();
IntPtr handle = p.MainWindowHandle;
while (handle == IntPtr.Zero)
{
await Task.Delay(TimeSpan.FromMilliseconds(250D));
handle = p.MainWindowHandle;
}
if (handle != IntPtr.Zero)
{
if (NativeMethods.IsIconic(handle))
NativeMethods.ShowWindowAsync(handle, SW_RESTORE);
if (NativeMethods.SetForegroundWindow(handle))
NativeMethods.SetActiveWindow(handle);
}
}
catch (InvalidOperationException) { }
catch (PlatformNotSupportedException) { }
catch (NotSupportedException) { }
catch (Exception ex) { ex.Log(); }
}).TimeoutAfter(TimeSpan.FromSeconds(3D));
}
catch (TimeoutException) { }
}
[SuppressUnmanagedCodeSecurity]
internal static class NativeMethods
{
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool IsIconic(System.IntPtr hWnd);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool SetForegroundWindow(System.IntPtr hWnd);
[DllImport("user32.dll")]
internal static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter,
int X, int Y, int cx, int cy, uint uFlags);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool ShowWindowAsync(System.IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")]
internal static extern System.IntPtr SetActiveWindow(System.IntPtr hWnd);
}
}
}
Try removing your call to SendWindowBack and replace SetForegroundWindow with SetWindowLong. This should meet your requierment:
...(or just behind the app that is launching) and STAY THERE..
const int GWL_HWNDPARENT = (-8);
[DllImport("user32.dll", SetLastError = true)]
static extern int SetWindowLong(IntPtr childHandle, int nIndex, IntPtr parentHandle);
if (handle != IntPtr.Zero)
{
if (NativeMethods.IsIconic(handle))
NativeMethods.ShowWindowAsync(handle, SW_RESTORE);
SetWindowLong(handle, GWL_HWNDPARENT, window.Handle)
NativeMethods.SetActiveWindow(handle);
}