I'd like to send a sequence of keypresses (to make up a word) to the window of a DirectX application followed by a pause before sending the ENTER key.
I'm able to send individual keypresses with the InputManager library, but I'm unsure of how to implement "waits" in between certain key sequences with this keyboard hook.
ie: Send the message "Hello", wait for 250ms followed by the ENTER key.
SendKeys and SendWait will not work for what I'm doing, as they will not send keystrokes to the DirectX application.
Here is some pseudo-code explaining what I'm trying to accomplish:
using InputManager;
namespace MyProject
{
public partial class form1: Form
{
private void helloButton_Click(object sender, EventArgs e)
{
Keyboard.KeyPress(Keys.H);
Keyboard.KeyPress(Keys.E);
Keyboard.KeyPress(Keys.L);
Keyboard.KeyPress(Keys.L);
Keyboard.KeyPress(Keys.O);
// (Wait 250ms)
Keyboard.KeyPress(Keys.Enter);
}
}
}
You can use Thread.Sleep(250);. This will pause the currently working thread for x amount of milliseconds.
Note that you will need to include System.Threading in your using statements.
Related
Im new to C#!
So my Problem: I got a C# Demo Program from an extern company, the program sets the settings of an extern device, than initialize it and starts recording the Data. The Data is written into the Console and streamed into a CSV at a Location i can choose. After pressing a Key in the Console the Recording stops. I am trying now to write a short GUI that starts and stops this Recording.
What I did:
I converted the main-method, which started the recoding, into a normal static method and deleted all writelines so the console doesnt start, than I created a Windows Form with 2 Buttons, one Start and One Stop. If I press Start, the Recording starts, but I cant do anything with the Gui it is like freeezed, a Console still appeares and i can only stop the process by pressing a key in the console.
Here is a snippit of the Console Code:
class BHJKL
{
system
private static A;
private static B;
// This method will be executed every time new data is received
static void OnNewDataReceived(object sender, NewDataEventArgs eventArgs)
{
//some code in here
using (StreamWriter file = new StreamWriter(#"C:\Users\XYZ\File_Trial" + DateTime.Now.DayOfYear + ".csv", true))
{
//Writeline data..
}
}
}
// This was the Main Method before i changed it
public static void Record()
{
// Here is some Code that configure the Settings of the device
// initialize device
// MORE CODE USING THE COMPANYS EXTERN LIBRARYS TO START THE DEVICE
//start device
deviceManager.DeviceStart();
while (!Console.KeyAvailable) // as long as no key is pressed do...
{
Thread.Sleep(100); // do nothing, let the event processing thread that is managed by the library handle incomming data
}
//stop device
deviceManager.DeviceStop();
//unsubscribe event
deviceManager.NewDataReceived -= OnNewDataReceived;
//deinitialize device
deviceManager.DeinitializeDevice();
//dispose device
deviceManager.Dispose();
}
}
My Attempt:
Changing the main method into static Recording.
Than by Pressing the Start Button, call the method.
Write this at the end of the method:
while (Rec==true)
{
Thread.Sleep(100);
}
By Pressing the Stop Button: set.Rec(false)
But after Pressing the start Button, i cant press the stop button anyome.
I hope someone can understand my Problem and can give me some advices.
Thread.Sleep blocks your UI from doing anything. Consider using a System.Windows.Forms.Timer
Rather than sleeping in a loop, you should just let your Start method return. Move all of the code that comes after the sleep loop into your Stop button's click event handler.
(Depending on how the code is structured, you may also have to switch deviceManager from being a local variable to being a field in the class)
I'm starting out in C#, coded a lot in Java but having some trouble here. I'm trying to learn how to use MouseKeyHook for an application I'm developing. I cannot get the actual listener to fire off an event. Here's my listener code:
using System;
using System.Windows.Forms;
using Gma.System.MouseKeyHook;
namespace ChromaHeatmap
{
class keyListener
{
private IKeyboardMouseEvents m_GlobalHook;
public void Subscribe()
{
// Note: for the application hook, use the Hook.AppEvents() instead
m_GlobalHook = Hook.GlobalEvents();
m_GlobalHook.KeyPress += GlobalHookKeyPress;
}
private void GlobalHookKeyPress(object sender, KeyPressEventArgs e)
{
Console.WriteLine("blah");
}
public void Unsubscribe()
{
m_GlobalHook.KeyPress -= GlobalHookKeyPress;
//It is recommened to dispose it
m_GlobalHook.Dispose();
}
}
}
And here's the part of my application code where I attempt to do something with the listener. If anyone can let me know what the best way is to loop here and wait for events, I'd appreciate it.
//Listen for key presses
keyListener heyListen = new keyListener();
heyListen.Subscribe();
while(true)
{
}
while(true) {}
This is a hold-and-catch-fire statement, the thread will burn 100% core and cannot execute the hook callback. You'll notice that the machine goes dead for 5 seconds when you press a key, the operating system is waiting for an opportunity to invoke the callback. But it won't wait forever and unceremoniously will destroy the hook so you regain control over the machine. Also the kind of mishap that will occur when you try to debug your event handler.
Windows needs an opportunity to safely call the hook callback. That requires your program to be "idle", not executing any code. The technical term for this is "pumping the message loop", your program must wait for a notification from the operating system that something interesting happened.
A very simple way is to use the Winforms project template as-is, you'll also get a window. Note how the Main() method in the project makes the call that you need instead of the while() loop. You must call Application.Run().
Check this post for code that avoids displaying a window.
I am trying to make an application that sends keys to an external application, in this case aerofly FS. I have previously used the SendKeys.SendWait() method with succes, but this time, it doesn't quite work the way I want it to. I want to send a "G" keystroke to the application and testing it out with Notepad I do get G's. But in aerofly FS nothing is recieved at all. Pressing G on the keyboard does work though.
This is my code handling input data (from an Arduino) an sending the keystrokes,
private void handleData(string curData)
{
if (curData == "1")
SendKeys.SendWait("G");
else
{ }
}
I too have run into external applications where SendKeys didn't work for me.
As best I can tell, some applications, like applets inside a browser, expect to receive the key down, followed by a pause, followed by a key up, which I don't think can be done with SendKeys.
I have been using a C# wrapper to the AutoIt Library, and have found it quite easy to use.
Here's a link to quick guide I wrote for integrating AutoIt into a C# project.
Once you have the wrapper and references, you can send "G" with the following:
private void pressG()
{
AutoItX3Declarations.AU3_Send("{g}");
}
or with a pause,
private void pressG()
{
AutoItX3Declarations.AU3_Send("{g down}", 0);
AutoItX3Declarations.AU3_Sleep( 50 ); //wait 50 milliseconds
AutoItX3Declarations.AU3_Send("{g up}", 0);
}
AutoIt also allows you programmatically control the mouse.
How do I simulate a key stroke in a window that is not my C# application ?
Right now i'm using SendKeys.Send() but it does not work. The thing is I have a global keyboard hook so I catch the input directly from the keyboard and SendKeys.Send() is not seen like a real keyboard stroke.
The best would be to simulate a real keystroke this way, no matter what is the application i'm in, my program will catch it as if someone pressed a key.
I guess I found part of the problem. This is the event called if a key is pressed :
static void KeyBoardHook_KeyPressed(object sender, KeyPressedEventArgs e)
{
// Writes the pressed key in the console (it works)
Console.WriteLine(e.KeyCode.ToString());
// Check if pressed key is Up Arrow (it works and enters the condition)
if(e.KeyCode == Keys.Up)
{
// Send the key again. (does not work)
SendKeys.Send("{UP}");
}
}
I tried it this way to :
static void KeyBoardHook_KeyPressed(object sender, KeyPressedEventArgs e)
{
// Writes the pressed key in the console (it works)
Console.WriteLine(e.KeyCode.ToString());
// Check if pressed key is Up Arrow (it works and enters the condition)
if(e.KeyCode == Keys.Up)
{
// Send the key again. (does not work)
PostMessage(proc.MainWindowHandle,WM_KEYDOWN, VK_UP,0);
}
}
but it does not work either. The thing is since I send the key inside my event, will it call itself because a key has been pressed ? In case someone needs it, the code above.
[STAThread]
static void Main(string args)
{
KeyBoardHook.CreateHook();
KeyBoardHook.KeyPressed += KeyBoardHook_KeyPressed;
Application.Run();
KeyBoardHook.Dispose();
}
if you need the KeyBoardHook class I can post it too.
My guess is that my keyboard hook is catching the low-level keyboard outputs and the SendKeys is just simulating a keystroke so my hook doesn't catch it. Anybody thinks of a work around ?
I suggest you use this very cool library that masks all the complexity for you, the Windows Input Simulator available here: http://inputsimulator.codeplex.com/
I believe it's based on the Windows' SendInput function.
You can p/invoke the keybd_event (which is much simpler and easier) or SendInput (which is newer and has more capabilities) functions, which simulate keyboard input at a much lower level.
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.