Shulou(Shulou.com)06/03 Report--

Editor to share with you how Android equipment to obtain scan gun scan content, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

Bar code scanning guns can now be seen everywhere, can quickly scan the bar code content, faster than what mobile phone camera scan code is not 1.2 points.

In order to save money, the code sweep gun can be directly connected to android or other devices through Bluetooth.

So how does an android device get scanned content via Bluetooth?

1. Bluetooth pairing, connecting devices

Open the system settings, find Bluetooth, turn on the code sweep gun, and match the code sweep gun equipment. Enter a fixed matching code, which is usually written in the manual of the code-scanning gun. After the pairing is complete, the display device is connected. Just ok.

Configure permissions in 2.AndroidManifest

Add Bluetooth permissions to the AndroidManifest.xml file in the android project.

3. Detect the connection status of the code sweep gun

Generally speaking, the code scanning gun equipment is also equivalent to the ordinary external input device type, external keyboard.

My code sweep gun device returns the following Bluetooth types.

BluetoothClass.Device.Major.PERIPHERAL

Generally speaking, the information of our code scanning gun equipment can be obtained in the following way.

Set blueDevices = mBluetoothAdapter.getBondedDevices (); if (blueDevices = = null | | blueDevices.size () 18, that is, android version 4.3 or later is available.

Later, I turned my head and thought that since the code sweep gun is also an input device, we can start with different Bluetooth device status detection and start with input device detection instead. So

Private void hasScanGun () {Configuration cfg = getResources () .getConfiguration (); return cfg.keyboard! = Configuration.KEYBOARD_NOKEYS;}

Got it.

4. Get the scan content of the code sweep gun

Since the scanning gun is an external input device, it is natural for us to start with KeyEvent.

Event resolution class

/ * * Code scan gun event resolution class * / public class ScanGunKeyEventHelper {/ / delay 500ms to determine whether the scan code is completed. Private final static long MESSAGE_DELAY = 500; / / scan code content private StringBuffer mStringBufferResult = new StringBuffer (); / / case sensitive private boolean mCaps; private OnScanSuccessListener mOnScanSuccessListener; private Handler mHandler = new Handler (); private final Runnable mScanningFishedRunnable = new Runnable () {@ Override public void run () {performScanSuccess ();}} / / return scan result private void performScanSuccess () {String barcode = mStringBufferResult.toString (); if (mOnScanSuccessListener! = null) mOnScanSuccessListener.onScanSuccess (barcode); mStringBufferResult.setLength (0);} / / key event handling public void analysisKeyEvent (KeyEvent event) {int keyCode = event.getKeyCode (); / / letter case judgment checkLetterStatus (event) If (event.getAction () = = KeyEvent.ACTION_DOWN) {char aChar = getInputCode (event);; if (aChar! = 0) {mStringBufferResult.append (aChar);} if (keyCode = = KeyEvent.KEYCODE_ENTER) {/ / if it is an enter key, return mHandler.removeCallbacks (mScanningFishedRunnable) directly MHandler.post (mScanningFishedRunnable);} else {/ / delay post. If there are other events in the 500ms, mHandler.removeCallbacks (mScanningFishedRunnable); mHandler.postDelayed (mScanningFishedRunnable, MESSAGE_DELAY);}} / / check the shift key private void checkLetterStatus (KeyEvent event) {int keyCode = event.getKeyCode () If (keyCode = = KeyEvent.KEYCODE_SHIFT_RIGHT | | keyCode = = KeyEvent.KEYCODE_SHIFT_LEFT) {if (event.getAction () = = KeyEvent.ACTION_DOWN) {/ / press the shift key to indicate uppercase mCaps = true;} else {/ / release the shift key, indicating lowercase mCaps = false } / / get scan content private char getInputCode (KeyEvent event) {int keyCode = event.getKeyCode (); char aChar; if (keyCode > = KeyEvent.KEYCODE_A & & keyCode = KeyEvent.KEYCODE_0 & & keyCode

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