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 ScanGunKeyEventHelperOnScanSuccessListener 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.onScanSuccessbarcode);
mStringBufferResult.setLength0);
}
/**
* 扫码枪事件解析
* @param event
*/
public void analysisKeyEventKeyEvent event) {
int keyCode = event.getKeyCode);
//字母大小写判断
checkLetterStatusevent);
if event.getAction) == KeyEvent.ACTION_DOWN) {
char aChar = getInputCodeevent);;
if aChar != 0) {
mStringBufferResult.appendaChar);
}
if keyCode == KeyEvent.KEYCODE_ENTER) {
//若为回车键，直接返回
mHandler.removeCallbacksmScanningFishedRunnable);
mHandler.postmScanningFishedRunnable);
} else {
//延迟post，若500ms内，有其他事件
mHandler.removeCallbacksmScanningFishedRunnable);
mHandler.postDelayedmScanningFishedRunnable, MESSAGE_DELAY);
}
}
}
//检查shift键
private void checkLetterStatusKeyEvent 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 getInputCodeKeyEvent 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 onScanSuccessString barcode);
}
public void onDestroy) {
mHandler.removeCallbacksmScanningFishedRunnable);
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 isInputDeviceExistmDeviceName);
// }
//
// }
//
// return false;
//
// }
/**
* 输入设备是否存在
* @param deviceName
* @return
*/
private boolean isInputDeviceExistString deviceName) {
int[] deviceIds = InputDevice.getDeviceIds);
for int id : deviceIds) {
if InputDevice.getDeviceid).getName).equalsdeviceName)) {
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 isScanGunEventKeyEvent event) {
return event.getDevice).getName).equalsmDeviceName);
}
}
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 onScanSuccessString 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 dispatchKeyEventKeyEvent event) {
mScanGunKeyEventHelper.analysisKeyEventevent);
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