这篇文章主要介绍了android中如何通过扫码枪读取手机二维码，具有一定借鉴价值，感兴趣的朋友可以参考下，希望大家阅读完这篇文章之后大有收获，下面让小编带着大家一起了解一下。
1.引入扫码设备辅助类
public class ScanGunKeyEventHelper {
private final static long MESSAGE_DELAY = 500; //延迟500ms，判断扫码是否完成。
private StringBuffer mStringBufferResult; //扫码内容
private boolean mCaps; //大小写区分
private final Handler mHandler;
private final BluetoothAdapter mBluetoothAdapter;
private final Runnable mScanningFishedRunnable;
private OnScanSuccessListener mOnScanSuccessListener;
private String mDeviceName;
public ScanGunKeyEventHelper(OnScanSuccessListener onScanSuccessListener) {
mOnScanSuccessListener = onScanSuccessListener ;
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
mStringBufferResult = new StringBuffer();
mHandler = new Handler();
mScanningFishedRunnable = new Runnable() {
@Override
public void run() {
performScanSuccess();
}
};
}
/**
* 返回扫码成功后的结果
*/
private void performScanSuccess() {
String barcode = mStringBufferResult.toString();
if (mOnScanSuccessListener != null)
mOnScanSuccessListener.onScanSuccess(barcode);
mStringBufferResult.setLength(0);
}
/**
* 扫码枪事件解析
* @param event
*/
public void analysisKeyEvent(KeyEvent event) {
int keyCode = event.getKeyCode();
//字母大小写判断
checkLetterStatus(event);
if (event.getAction() == KeyEvent.ACTION_DOWN) {
char aChar = getInputCode(event);;
if (aChar != 0) {
mStringBufferResult.append(aChar);
}
if (keyCode == KeyEvent.KEYCODE_ENTER) {
//若为回车键，直接返回
mHandler.removeCallbacks(mScanningFishedRunnable);
mHandler.post(mScanningFishedRunnable);
} else {
//延迟post，若500ms内，有其他事件
mHandler.removeCallbacks(mScanningFishedRunnable);
mHandler.postDelayed(mScanningFishedRunnable, MESSAGE_DELAY);
}
}
}
//检查shift键
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) {
//按着shift键，表示大写
mCaps = true;
} else {
//松开shift键，表示小写
mCaps = false;
}
}
}
//获取扫描内容
private char getInputCode(KeyEvent event) {
int keyCode = event.getKeyCode();
char aChar;
if (keyCode >= KeyEvent.KEYCODE_A && keyCode <= KeyEvent.KEYCODE_Z) {
//字母
aChar = (char) ((mCaps ? 'A' : 'a') + keyCode - KeyEvent.KEYCODE_A);
} else if (keyCode >= KeyEvent.KEYCODE_0 && keyCode <= KeyEvent.KEYCODE_9) {
//数字
aChar = (char) ('0' + keyCode - KeyEvent.KEYCODE_0);
} else {
//其他符号
switch (keyCode) {
case KeyEvent.KEYCODE_PERIOD:
aChar = '.';
break;
case KeyEvent.KEYCODE_MINUS:
aChar = mCaps ? '_' : '-';
break;
case KeyEvent.KEYCODE_SLASH:
aChar = '/';
break;
case KeyEvent.KEYCODE_BACKSLASH:
aChar = mCaps ? '|' : '\\';
break;
default:
aChar = 0;
break;
}
}
return aChar;
}
public interface OnScanSuccessListener {
void onScanSuccess(String barcode);
}
public void onDestroy() {
mHandler.removeCallbacks(mScanningFishedRunnable);
mOnScanSuccessListener = null;
}
//部分手机如三星，无法使用该方法
// private void hasScanGun() {
// Configuration cfg = getResources().getConfiguration();
// return cfg.keyboard != Configuration.KEYBOARD_NOKEYS;
// }
// /**
// * 扫描枪是否连接
// * @return
// */
// public boolean hasScanGun() {
//
// if (mBluetoothAdapter == null) {
// return false;
// }
//
// Set<BluetoothDevice> blueDevices = mBluetoothAdapter.getBondedDevices();
//
// if (blueDevices == null || blueDevices.size() <= 0) {
// return false;
// }
//
// for (Iterator<BluetoothDevice> iterator = blueDevices.iterator(); iterator.hasNext(); ) {
// BluetoothDevice bluetoothDevice = iterator.next();
//
// if (bluetoothDevice.getBluetoothClass().getMajorDeviceClass() == BluetoothClass.Device.Major.PERIPHERAL) {
// mDeviceName = bluetoothDevice.getName();
// return isInputDeviceExist(mDeviceName);
// }
//
// }
//
// return false;
//
// }
/**
* 输入设备是否存在
* @param deviceName
* @return
*/
private boolean isInputDeviceExist(String deviceName) {
int[] deviceIds = InputDevice.getDeviceIds();
for (int id : deviceIds) {
if (InputDevice.getDevice(id).getName().equals(deviceName)) {
return true;
}
}
return false;
}
/**
* 是否为扫码枪事件(部分机型KeyEvent获取的名字错误)
* @param event
* @return
*/
@Deprecated
public boolean isScanGunEvent(KeyEvent event) {
return event.getDevice().getName().equals(mDeviceName);
}
}2. active里面实现代理方法
//实现上述类接口‘
public class MainActivity extends AppCompatActivity implements
ScanGunKeyEventHelper.OnScanSuccessListener
//重写扫码枪识别返回数据
@Override
public void onScanSuccess(String barcode) {
barCode = barcode;
if (barcode != null && recordPrice > 0 && payString.equals
("readyPay")) {
payDishs();
}
}
//重写捕捉到扫码枪事件
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
mScanGunKeyEventHelper.analysisKeyEvent(event);
return true;
}dispatchKeyEvent里面分发事件一定设置 return true，否则扫码枪事件传递到屏幕其他按钮上
感谢你能够认真阅读完这篇文章，希望小编分享的“android中如何通过扫码枪读取手机二维码”这篇文章对大家有帮助，同时也希望大家多多支持亿速云，关注亿速云行业资讯频道，更多相关知识等着你来学习!
免责声明：本站发布的内容（图片、视频和文字）以原创、转载和分享为主，文章观点不代表本网站立场，如果涉及侵权请联系站长邮箱：is@yisu.com进行举报，并提供相关证据，一经查实，将立刻删除涉嫌侵权内容。
