I managed to get the position (x,y) of mousse clicked event in windows with C# and Win32 API from the code at http://www.codeproject.com/KB/cs/globalhook.aspx (using Version 1 because I have a problem with version 2)
But I want to know what is clicked not the position on the screen.
For example, click the "Bold Button" in MS Word.
Is there a way to archive this?
Thanks in advance.
You can fetch a window handle from WindowFromPoint or ChildWindowFromPointEx, then query the window handle with GetWindowInfo etc. I don't think there's a trivial way to identify a button from Word, though.
Check out the AutomationElement.FromPoint() that's part of UI Automation - this suite of APIs is often used by automated test and accessibility apps that want to get information about the UI of other processes. For apps that support it (most of the UI in Windows and most MS apps), you can get information about the UI element, not just the outer window. This sample app prints out the name and type (eg 'button') of the item under the cursor.
It's not supported everywhere, may not work in many non-MS apps (though is supported by Firefox); but will at least get you better results than WindowFromPoint etc.
// Compile using: csc ItemAtPoint.cs /r:UIAutomationClient.dll /r:WindowsBase.dll
using System;
using System.Windows.Automation;
using System.Windows.Forms;
class ItemAtPoint
{
public static void Main()
{
Console.WriteLine("Place pointer over item and hit return...");
Console.ReadLine();
// Get the AutomationElement that represents the window handle...
System.Windows.Point point = new System.Windows.Point(Cursor.Position.X, Cursor.Position.Y);
AutomationElement el = AutomationElement.FromPoint(point);
// Print out the type of the item and its name
Console.WriteLine("item is a \"{0}\" with name \"{1}\"", el.Current.LocalizedControlType, el.Current.Name);
}
}
Related
I have a barcode scanner (which acts like a keyboard) and of course I have a keyboard too hooked up to a computer. The software is accepting input from both the scanner and the keyboard. I need to accept only the scanner's input. The code is written in C#. Is there a way to "disable" input from the keyboard and only accept input from the scanner?
Note:
Keyboard is part of a laptop...so it cannot be unplugged. Also, I tried putting the following code
protected override Boolean ProcessDialogKey(System.Windows.Forms.Keys keyData)
{
return true;
}
But then along with ignoring the keystrokes from the keyboard, the barcode scanner input is also ignored.
I cannot have the scanner send sentinal characters as, the scanner is being used by other applications and adding a sentinal character stream would mean modifying other code.
Also, I cannot use the timing method of determining if the input came from a barcode scanner (if its a bunch of characters followed by a pause) since the barcodes scanned could potentially be single character barcodes.
Yes, I am reading data from a stream.
I am trying to follow along with the article: Distinguishing Barcode Scanners from the Keyboard in WinForms. However I have the following questions:
I get an error NativeMethods is inaccessible due to its protection level. It seems as though I need to import a dll; is this correct? If so, how do I do it?
Which protected override void WndProc(ref Message m) definition should I use, there are two implementations in the article?
Am getting an error related to [SecurityPermission( SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)] error CS0246: The type or namespace name 'SecurityPermission' could not be found (are you missing a using directive or an assembly reference?). How do I resolve this error?
There is also an error on the line containing: if ((from hardwareId in hardwareIds where deviceName.Contains(hardwareId) select hardwareId).Count() > 0) Error is error CS1026: ) expected.
Should I be placing all the code in the article in one .cs file called BarcodeScannerListener.cs?
Followup questions about C# solution source code posted by Nicholas Piasecki on http://nicholas.piasecki.name/blog/2009/02/distinguishing-barcode-scanners-from-the-keyboard-in-winforms/:
I was not able to open the solution in VS 2005, so I downloaded Visual C# 2008 Express Edition, and the code ran. However, after hooking up my barcode scanner and scanning a barcode, the program did not recognize the scan. I put a break point in OnBarcodeScanned method but it never got hit. I did change the App.config with the id of my Barcode scanner obtained using Device Manager. There seems to be 2 deviceNames with HID#Vid_0536&Pid_01c1 (which is obtained from Device Manager when the scanner is hooked up). I don't know if this is causing the scanning not to work. When iterating over the deviceNames, here is the list of devices I found (using the debugger):
"\??\HID#Vid_0536&Pid_01c1&MI_01#9&25ca5370&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}"
"\??\HID#Vid_0536&Pid_01c1&MI_00#9&38e10b9&0&0000#{884b96c3-56ef-11d1-bc8c-00a0c91405dd}"
"\??\HID#Vid_413c&Pid_2101&MI_00#8&1966e83d&0&0000#{884b96c3-56ef-11d1-bc8c-00a0c91405dd}"
"\??\HID#Vid_413c&Pid_3012#7&960fae0&0&0000#{378de44c-56ef-11d1-bc8c-00a0c91405dd}"
"\??\Root#RDP_KBD#0000#{884b96c3-56ef-11d1-bc8c-00a0c91405dd}"
"\??\ACPI#PNP0303#4&2f94427b&0#{884b96c3-56ef-11d1-bc8c-00a0c91405dd}"
"\??\Root#RDP_MOU#0000#{378de44c-56ef-11d1-bc8c-00a0c91405dd}"
"\??\ACPI#PNP0F13#4&2f94427b&0#{378de44c-56ef-11d1-bc8c-00a0c91405dd}"
So there are 2 entries for HID#Vid_0536&Pid_01c1; could that be causing the scanning not to work?
OK so it seems that I had to figure out a way to not depend on the ASCII 0x04 character being sent by the scanner...since my scanner does not send that character. After that, the barcode scanned event is fired and the popup with the barcode is shown. So thanks Nicholas for your help.
You could use the Raw Input API to distinguish between the keyboard and the scanner like I did recently. It doesn't matter how many keyboard or keyboard-like devices you have hooked up; you will see a WM_INPUT before the keystroke is mapped to a device-independent virtual key that you typically see in a KeyDown event.
Far easier is to do what others have recommended and configure the scanner to send sentinel characters before and after the barcode. (You usually do this by scanning special barcodes in the back of the scanner's user manual.) Then, your main form's KeyPreview event can watch those roll end and swallow the key events for any child control if it's in the middle of a barcode read. Or, if you wanted to be fancier, you could use a low-level keyboard hook with SetWindowsHookEx() to watch for those sentinels and swallow them there (advantage of this is you could still get the event even if your app didn't have focus).
I couldn't change the sentinel values on our barcode scanners among other things so I had to go the complicated route. Was definitely painful. Keep it simple if you can!
--
Your update, seven years later: If your use case is reading from a USB barcode scanner, Windows 10 has a nice, friendly API for this built-in in Windows.Devices.PointOfService.BarcodeScanner. It's a UWP/WinRT API, but you can use it from a regular desktop app as well; that's what I'm doing now. Here's some example code for it, straight from my app, to give you the gist:
{
using System;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using Windows.Devices.Enumeration;
using Windows.Devices.PointOfService;
using Windows.Storage.Streams;
using PosBarcodeScanner = Windows.Devices.PointOfService.BarcodeScanner;
public class BarcodeScanner : IBarcodeScanner, IDisposable
{
private ClaimedBarcodeScanner scanner;
public event EventHandler<BarcodeScannedEventArgs> BarcodeScanned;
~BarcodeScanner()
{
this.Dispose(false);
}
public bool Exists
{
get
{
return this.scanner != null;
}
}
public void Dispose()
{
this.Dispose(true);
GC.SuppressFinalize(this);
}
public async Task StartAsync()
{
if (this.scanner == null)
{
var collection = await DeviceInformation.FindAllAsync(PosBarcodeScanner.GetDeviceSelector());
if (collection != null && collection.Count > 0)
{
var identity = collection.First().Id;
var device = await PosBarcodeScanner.FromIdAsync(identity);
if (device != null)
{
this.scanner = await device.ClaimScannerAsync();
if (this.scanner != null)
{
this.scanner.IsDecodeDataEnabled = true;
this.scanner.ReleaseDeviceRequested += WhenScannerReleaseDeviceRequested;
this.scanner.DataReceived += WhenScannerDataReceived;
await this.scanner.EnableAsync();
}
}
}
}
}
private void WhenScannerDataReceived(object sender, BarcodeScannerDataReceivedEventArgs args)
{
var data = args.Report.ScanDataLabel;
using (var reader = DataReader.FromBuffer(data))
{
var text = reader.ReadString(data.Length);
var bsea = new BarcodeScannedEventArgs(text);
this.BarcodeScanned?.Invoke(this, bsea);
}
}
private void WhenScannerReleaseDeviceRequested(object sender, ClaimedBarcodeScanner args)
{
args.RetainDevice();
}
private void Dispose(bool disposing)
{
if (disposing)
{
this.scanner = null;
}
}
}
}
Granted, you'll need a barcode scanner that supports the USB HID POS and isn't just a keyboard wedge. If your scanner is just a keyboard wedge, I recommend picking up something like a used Honeywell 4600G off eBay for like $25. Trust me, your sanity will be worth it.
What I did in a similar situation is distinguish between a scan and a user typing by looking at the speed of the input.
Lots of characters very close together then a pause is a scan. Anything else is keyboard input.
I don't know exactly your requirements, so maybe that won't do for you, but it's the best I've got :)
It depends on the way you are interacting with the device. Anyway it wont be a C# solution, it will be some other library. Are you reading data from a stream? If you are just taking keystrokes, there may be nothing you can do about it.
I know this is an old thread, found it by searching barcode scanning in WIN10.
Just a few notes in case someone needs it.
These scanners from Honeywell have several USB interfaces.
One is a keyboard + Hid Point of sales (composite device).
Also there are CDC-ACM (ComPort emulation) and Hid Point of sales (alone) + more.
By default the scanners expose a serial number, so the host can distinguish between many devices (I had once +20 connected). There is a command to disable the serial number though!
The newer models behave the same in this regard.
If you want to see it live, try my terminal program yat3 (free on my site).
It can open all the interfaces mentioned above and is tailored for such devices.
A word to use keyboard interfaces:
Only use them as a last resort. They are slow, less reliable when it comes to exotic characters. The only good use is if you want to enter data into existing applications. If you code anyway, then reading from ComPort/HidPos-Device is easier.
look at this: http://nate.dynalias.net/dev/keyboardredirector.rails (NOT AVAILABLE ANYMORE) works great!
Specify the keyboard and the keys you want to block, and it works like a charm!
Also take a look at this: http://www.oblita.com/interception.html
You can create a C# wrapper for it - it also works like a charm..
I think you might be able to distinguish multiple keyboards through DirectX API, or if that doesn't work, through raw input API.
I have successfully accomplished what you folks are looking for here. I have an application that receives all barcode character data from a Honeywell/Metrologic barcode scanner. No other application on the system receives the data from the scanner, and the keyboard continues to function normally.
My application uses a combination of raw input and the dreaded low-level keyboard hook system. Contrary to what is written here, I found that the wm_input message is received before the keyboard hook function is called. My code to process the wm_input message basically sets a boolean variable to specify whether or not the received character is from the scanner. The keyboard hook function, called immediately after the wm_input is processed, swallows the scanner’s pseudo-keyboard data, preventing the data from being received by other applications.
The keyboard hook function has to be placed in an dll since you want to intercept all system keyboard messages. Also, a memory mapped file has to be used for the wm_input processing code to communicate with the dll.
I have two .NET applications:
parent-app.exe (WPF)
child-app.exe (WinForms)
The first application starts the second one
parent-app.exe → child-app.exe
by means of the class System.Diagnostics.Process.
When user clicks a button on the interface of the parent-app.exe, I start the process of child-app.exe immediately. Because child-app.exe is a .NET application, is takes some time before user could see the window (especially, on slow systems).
I want to show the user an intermediate (possibly dialog) window from parent-app.exe. This dialog window should say that user action is being processed and he should wait for the window of child-app.exe to show up.
Questions:
How can I check from parent-app.exe visibility state of the window of child-app.exe?
Here is the longer question. How would you implement this system of showing intermediate window by taking into account the restriction
that both programs use .NET?
As suggested here, you can try calling the Process.WaitForInputIdle method to wait for the MainWindowHandle to be created or periodically calling Process.Refresh and check if MainWindowHandle returns a valid handle. Perhaps this is enough for you, otherwise you can get additional information with the handle. In WinForms you could probably do something like this:
Form window = (Form)Control.FromHandle(process.MainWindowHandle);
I suspect there are similar solutions for other frameworks.
Update
I wrote this small sample, it is untested and I don't know if it works reliably (it may deadlock), but it should hint at some things you can try:
namespace SomeNS
{
using System.Diagnostics;
using System.Windows.Forms;
public static class SomeClass
{
static void SomeMethod()
{
Process process = Process.Start("child-app.exe");
// YourDialog is your dialog implementation inheriting from System.Windows.Window
YourDialog dlg = new YourDialog();
dlg.Loaded += (sender, e) =>
{
process.WaitForInputIdle();
Form window = (Form)Control.FromHandle(process.MainWindowHandle);
// Do something with the child app's window
dlg.Close();
};
dlg.ShowDialog();
}
}
}
I want to know whether there is any event triggered when a new window appears/comes on the desktop. I am open to using COM,WMI,WinApis, UIAutomation or any other method but the language of choice is C#.
The actual requirement:
A process has 1 main window and many other windows. The class name of one of the windows is, say, X, (i got this info using pinvoke). Now this window pops up some times whenever there is some notification in the process. I do not want to show this window. I do not have code access to that process so that i can disable that window. So is there any way that i can get an event or any other mechanism which keeps track of the desktop and anytime a window with classname X comes/about to come it hides it.
Do tell if i am not clear with the question.
Thanks
EDIT : Simon's answer is really good. I tried that and am able to get notification for all windows except notifications/toast windows such as that of lync's im toast notification or outlook new mail notification. I tried with different elements of Automation Element and Windows Pattern but still could not get those...Any ideas how i can get those...you may read comments in Simon's answer for more context/detail. Once again thanks to Simon for introducing to the great power of UIAUtomation...Loving it!
As Damien said in his comment, you can use UI automation, like this in a C# sample console app:
class Program
{
static void Main(string[] args)
{
Automation.AddAutomationEventHandler(WindowPattern.WindowOpenedEvent, AutomationElement.RootElement, TreeScope.Subtree, (sender, e) =>
{
AutomationElement src = sender as AutomationElement;
if (src != null)
{
Console.WriteLine("Class : " + src.Current.ClassName);
Console.WriteLine("Title : " + src.Current.Name);
Console.WriteLine("Handle: " + src.Current.NativeWindowHandle);
}
});
Console.WriteLine("Press any key to quit...");
Console.ReadKey(true);
}
}
One option is RegisterShellHookWindow. You supply a window handle that can receive notification messages. The notifications that could be useful to you are HSHELL_WINDOWCREATED or HSHELL_WINDOWACTIVATED.
Here MSDN has provided code for registering for windows notifications. But this is specific to Windows Sever 2008. I think similar you can find for your version of Window.
I am writing a C# WPF program which sends text messages to another program's window. I have a macro program as part of my keyboard drivers (Logitech g15) which already does this, though it does not send keystrokes directly to the process, but to the currently focused window. It works well but i need to be able to send inputs from my program as well. There are other people using the process so the input text messages from my program needs to be fast enough so that my text does not interfere with their input.
The problem is that when I try to do this with a c# program I get too much delay. The macro program (Logitech G-Series Profiler) sends a command instantly. I have tried the following three commands for sending messages to process. (Listed by order of slowest to fastest)
SetForegroundWindow(_hWnd);
SendKeys.SendWait("{Enter}This is a keystroke input.{Enter}");
It is probably in the name, but this performs the command so slowly that I can actually follow with my eyes the text as it is input letter by letter. I have tried using the “SendKeys.Send” method but I get an error saying: “SendKeys cannot run inside this application because the application is not handling Windows messages.”
PostMessage((IntPtr)_hWnd, (uint)WMessages.WM_KEYUP, (int)key, (int)key);
PostMessage is a bit faster but still not fast enough for the purpose of my program. Besides the method returns before the message has been read by the process, which means two sequential PostMessage calls may not send sequential messages.
SendMessage(_hWnd, 0x100, (int) VKeys.VK_2, (int) VKeys.VK_2);
This is faster than the PostMessage but not nearly as fast as the macro program from Logitech. Also, the receiving program handles the input strangely, apparently not treating it the same way it does "genuine" input from the keyboard.
SetForegroundWindow(_hWnd);
const string text = "This is a keystroke input.";
IInputElement target = Keyboard.FocusedElement;
IInputElement target = InputManager.Current.PrimaryKeyboardDevice.FocusedElement;
var routedEvent = TextCompositionManager.TextInputEvent;
target.RaiseEvent(new TextCompositionEventArgs(InputManager.Current.PrimaryKeyboardDevice, new TextComposition(InputManager.Current, target, text)) { RoutedEvent = routedEvent });
This is the last thing I have tried. It seems instant with the way the text is sent to a process. However, I have only been able to send this to my own program since Keyboard.FocusedElement returns null when I have another program set as foreground window.
If someone can tell me how to get an IInputElement of another window I would sure like to know. Alternatively, if someone has a suggestion for a better method of sending input, I would dearly like to hear it.
Specs: Windows 7, 64bit
Visual Studio 2010, Framework 4
First of all, are you intentionally using WM_KEYDOWN (0x0100) instead of WM_KEYUP (0x0101) in your SendMessage example? This would just press the keys, and never release them, so the application would not process them properly.
Another way worth trying would be to send WM_SETTEXT, assuming the control interprets it correctly (like edit controls or combo boxes).
A last option would be to use SendInput which synthesizes keyboard and mouse input on a very low level, but similarly to you keyboard's macro program, this requires you to activate the correct window and set the focus, which can be quite painful.
Depending on your other's program window type, you could use UI Automation. See this example here:
Add Content to a Text Box Using UI Automation
My program A launched program B (both are separate exe's). Now my program B need to find if A have any modal/child window open using A's processID.
Is there any way to do so?
Thanks a lot for your help.
You might be able to use some of the suggestions from this question (if you don't mind using Win32 calls).
I found the soln.
1. Get handle of parent window A.
PerformanceCounter perId = new PerformanceCounter("Process", "Creating Process ID", Process.GetCurrentProcess().ProcessName);
2. Use GetLastActivePopup method to get last active popup (Last popup works in my case :) ) .