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POUSB Barcode Scanner and WM_KEYDOWN
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  1. POUSB Barcode Scanner and WM_KEYDOWN
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    copied!<p>I am trying to write a program that can will read a barcode scanner. In addition, I need it to read the input even when the application is not the window in focus (i.e., running in system tray, etc).</p> <p>I found this article, titled <a href="http://nicholas.piasecki.name/blog/2009/02/distinguishing-barcode-scanners-from-the-keyboard-in-winforms/" rel="nofollow noreferrer">Distinguishing Barcode Scanners from the Keyboard in WinForms</a>, that seems to solve the exact problem. It is working pretty good, it detects my device and handles the WM_INPUT message.</p> <p>However, it is checking to see if the RAWINPUT.keyboard.Message is WM_KEYDOWN (0x100). It never seems to receive this. The only line of code I've altered in the code provided in the <a href="http://nicholas.piasecki.name/blog/2009/02/distinguishing-barcode-scanners-from-the-keyboard-in-winforms/" rel="nofollow noreferrer">article</a> is adding a Console.Out.WriteLine to output the actual values of that message:</p> <pre><code>Console.Out.WriteLine("message: {0}", raw.keyboard.Message.ToString("X")); if (raw.keyboard.Message == NativeMethods.WM_KEYDOWN) { .... </code></pre> <p>Here is what it outputs:</p> <pre><code>message: B message: 1000B message: 3 message: 10003 message: 8 message: 10008 message: 3 message: 10003 message: 5 message: 10005 message: 3 message: 10003 message: 8 message: 10008 message: 8 message: 10008 message: 4 message: 10004 message: 9 message: 10009 message: 9 message: 10009 message: 3 message: 10003 </code></pre> <p>The value I'm expecting to receive when this completes correctly is:</p> <pre><code>257232709 </code></pre> <p>Which I verified by scanning to notepad.</p> <p>I don't know if the Operation System is relevant here, but I figured I should mention that I'm running this in Windows 7 64 and Visual Studio 2010 and .NET Framework 3.5. Scanner is a USB Barcode Scanner, Symbol LS2208, setup as "HID KEYBOARD EMULATION"</p>
 

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