windows not in focus
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Hello, I have a textbox in my window application. I want to be able to write into the textbox even if the application window not in focus (not "first" on the screen). How can i do it? If i need to use events for it , i don't know exacly how to write an event and where to put each code piece (the event handler etc.)
Sounds like a weird requirement. Don't you think it will be weird for the users? I mean you type in something on a form and it is shown at a very different location.
50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong...!!
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Hello, I have a textbox in my window application. I want to be able to write into the textbox even if the application window not in focus (not "first" on the screen). How can i do it? If i need to use events for it , i don't know exacly how to write an event and where to put each code piece (the event handler etc.)
I am trying to understand what you want to achieve. Is it: "I have a windows app which contains a textbox. Even if the windows app does not have the focus, but Notepad does, I want user input to go into my textbox" or "I have a windows app which contains a textbox. Even if the windows app does not have the focus, but Notepad does, I want my app to be able to insert text into my textbox" The former is not normal at all - and I don't think it can be done. The latter happens without any work at all. If these do not describe what your problem is, then please try to restate it and we'll see what we can do.
All those who believe in psycho kinesis, raise my hand.
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I am trying to understand what you want to achieve. Is it: "I have a windows app which contains a textbox. Even if the windows app does not have the focus, but Notepad does, I want user input to go into my textbox" or "I have a windows app which contains a textbox. Even if the windows app does not have the focus, but Notepad does, I want my app to be able to insert text into my textbox" The former is not normal at all - and I don't think it can be done. The latter happens without any work at all. If these do not describe what your problem is, then please try to restate it and we'll see what we can do.
All those who believe in psycho kinesis, raise my hand.
The purpose of it is that i want the program will read data from a barcode reader and then display it on the textbox, even if the window is not it focus
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The purpose of it is that i want the program will read data from a barcode reader and then display it on the textbox, even if the window is not it focus
If the barcode reader emulates a keyboard, then you can't - at least not without hooking into the OS and diverting every keystroke to your app, which may annoy the user, and probably not work in anything with a virus scanner running! How does your BC reader work? Does it have a serial or USB interface that does not emulate a keyboard?
All those who believe in psycho kinesis, raise my hand.
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If the barcode reader emulates a keyboard, then you can't - at least not without hooking into the OS and diverting every keystroke to your app, which may annoy the user, and probably not work in anything with a virus scanner running! How does your BC reader work? Does it have a serial or USB interface that does not emulate a keyboard?
All those who believe in psycho kinesis, raise my hand.
Yes, It works as keyboard amulator...
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Yes, It works as keyboard amulator...
Then you have a problem. all the Keyboard emulating BCRs I have seen read teh BC and just provide a datastream as if the barcode data had been typed by the user. For example, if the BC was 092939201610 then the BCR fakes teh keyboard keystrokes for '0' down, '0 up, '9' down, '9' up, etc. There is no way to tell if the real KB or the BCR provided the data, so would have to feed all keyboard data to your progam. As a user this would: 1) be very annoying and 2) look like a memory resident key logger. Your best bet is to talk to the manufacturer and see if they have done similar before.
All those who believe in psycho kinesis, raise my hand.
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Then you have a problem. all the Keyboard emulating BCRs I have seen read teh BC and just provide a datastream as if the barcode data had been typed by the user. For example, if the BC was 092939201610 then the BCR fakes teh keyboard keystrokes for '0' down, '0 up, '9' down, '9' up, etc. There is no way to tell if the real KB or the BCR provided the data, so would have to feed all keyboard data to your progam. As a user this would: 1) be very annoying and 2) look like a memory resident key logger. Your best bet is to talk to the manufacturer and see if they have done similar before.
All those who believe in psycho kinesis, raise my hand.
OriginalGriff wrote:
Then you have a problem. all the Keyboard emulating BCRs I have seen read teh BC and just provide a datastream as if the barcode data had been typed by the user.
I feel it's all ok. User such as a cashier isn't supposed to use a keyboard very often. So we can redirect BC stream to the textbox. In the textbox handler we can validate BC/user input. For example - user always start typing session with "A" char, else it's BC's chars.
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Yes, It works as keyboard amulator...
I can understand if you are developing a POS system you may want this input to be directed to the textbox. You could always try setting the KeyPreview to True on the Form. Then on the KeyPress you could try
private void YourForm\_KeyPress(object sender, KeyPressEventArgs e) { ScannerFirstKeyValue = e.KeyChar.ToString(); if (this.ActiveControl != this.YourTextBox) { YourTextBox.AppendText(ScannerFirstKeyValue); } this.ActiveControl = YourTextBox; }This would ensure all input is placed in correct textbox. Remember if you have multiple textboxes this will be a problem!! Unless the BC Reader has some sort of prefix that can distinguish it from a keyboard.
Regards Mick Curley :)
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I can understand if you are developing a POS system you may want this input to be directed to the textbox. You could always try setting the KeyPreview to True on the Form. Then on the KeyPress you could try
private void YourForm\_KeyPress(object sender, KeyPressEventArgs e) { ScannerFirstKeyValue = e.KeyChar.ToString(); if (this.ActiveControl != this.YourTextBox) { YourTextBox.AppendText(ScannerFirstKeyValue); } this.ActiveControl = YourTextBox; }This would ensure all input is placed in correct textbox. Remember if you have multiple textboxes this will be a problem!! Unless the BC Reader has some sort of prefix that can distinguish it from a keyboard.
Regards Mick Curley :)
doesn't that prevent people from typing anything in any other Control? :)
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
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doesn't that prevent people from typing anything in any other Control? :)
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
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doesn't that prevent people from typing anything in any other Control? :)
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
Hi, I need this thing only to read data from barcode reader. Is there a way so only data from it (COM1 port for example) will be insereted to that textbox or the clipboard even if the application is not in focus (in background)?
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Hello, I have a textbox in my window application. I want to be able to write into the textbox even if the application window not in focus (not "first" on the screen). How can i do it? If i need to use events for it , i don't know exacly how to write an event and where to put each code piece (the event handler etc.)
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I think that you need create a windows service. When the computer got data, the service app show the data on the form's textbox, even the form unfocused.
OK how can i do it using my application?
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Hi, I need this thing only to read data from barcode reader. Is there a way so only data from it (COM1 port for example) will be insereted to that textbox or the clipboard even if the application is not in focus (in background)?
Although it's rather unwieldy task I guess I know a way to perform it. To interact with an application that is not in focus I recommend you to use windows application log. Create the window service to handle BC input and write it down to the Log. In the application - check the Log for new entries on timer event and if it exists put it into your textbox. So despite your application might be not in focuse it still can achieve data from BC.
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Although it's rather unwieldy task I guess I know a way to perform it. To interact with an application that is not in focus I recommend you to use windows application log. Create the window service to handle BC input and write it down to the Log. In the application - check the Log for new entries on timer event and if it exists put it into your textbox. So despite your application might be not in focuse it still can achieve data from BC.
i think a better way is to create a windows service that will read the data from the Barcode reader and then put in in the clipboard. But i don't know how to create such service and how to read from this device (USB port)
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Hello, I have a textbox in my window application. I want to be able to write into the textbox even if the application window not in focus (not "first" on the screen). How can i do it? If i need to use events for it , i don't know exacly how to write an event and where to put each code piece (the event handler etc.)
To capture Keyboard stream use hooks Read this http://msdn.microsoft.com/en-us/library/ms632589(VS.85).aspx[^] Simple example
using System; using System.Collections.Generic; using System.Text; using System.Diagnostics; using System.Runtime.InteropServices; namespace hook { class Program { private const int WH_KEYBOARD_LL = 13; private const int WM_KEYDOWN = 0x0100; private static LowLevelKeyboardProc _proc = HookCallback; private static IntPtr _hookID = IntPtr.Zero; static void Main() { _hookID = SetHook(_proc); Application.Run(); UnhookWindowsHookEx(_hookID); } private static IntPtr SetHook(LowLevelKeyboardProc proc) { using (Process curProcess = Process.GetCurrentProcess()) using (ProcessModule curModule = curProcess.MainModule) { return SetWindowsHookEx(WH_KEYBOARD_LL, proc, GetModuleHandle(curModule.ModuleName), 0); } } private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam); private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam) { if ((nCode >= 0) && (wParam == (IntPtr)WM_KEYDOWN)) { int vkCode = Marshal.ReadInt32(lParam); if (((Keys)vkCode == Keys.LWin) || ((Keys)vkCode == Keys.RWin)) { Console.WriteLine("{0} blocked!", (Keys)vkCode); return (IntPtr)1; } } return CallNextHookEx(_hookID, nCode, wParam, lParam); } [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId); [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern bool UnhookWindowsHookEx(IntPtr hhk); [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam); [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)] -
i think a better way is to create a windows service that will read the data from the Barcode reader and then put in in the clipboard. But i don't know how to create such service and how to read from this device (USB port)
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To capture Keyboard stream use hooks Read this http://msdn.microsoft.com/en-us/library/ms632589(VS.85).aspx[^] Simple example
using System; using System.Collections.Generic; using System.Text; using System.Diagnostics; using System.Runtime.InteropServices; namespace hook { class Program { private const int WH_KEYBOARD_LL = 13; private const int WM_KEYDOWN = 0x0100; private static LowLevelKeyboardProc _proc = HookCallback; private static IntPtr _hookID = IntPtr.Zero; static void Main() { _hookID = SetHook(_proc); Application.Run(); UnhookWindowsHookEx(_hookID); } private static IntPtr SetHook(LowLevelKeyboardProc proc) { using (Process curProcess = Process.GetCurrentProcess()) using (ProcessModule curModule = curProcess.MainModule) { return SetWindowsHookEx(WH_KEYBOARD_LL, proc, GetModuleHandle(curModule.ModuleName), 0); } } private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam); private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam) { if ((nCode >= 0) && (wParam == (IntPtr)WM_KEYDOWN)) { int vkCode = Marshal.ReadInt32(lParam); if (((Keys)vkCode == Keys.LWin) || ((Keys)vkCode == Keys.RWin)) { Console.WriteLine("{0} blocked!", (Keys)vkCode); return (IntPtr)1; } } return CallNextHookEx(_hookID, nCode, wParam, lParam); } [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId); [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern bool UnhookWindowsHookEx(IntPtr hhk); [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam); [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]how do i use this code? where do i put in? in the program.cs ? and is it a windows service?
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I think that you need create a windows service. When the computer got data, the service app show the data on the form's textbox, even the form unfocused.
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OK how can i do it using my application?
