【发布时间】：2021-03-06 15:38:17
【问题描述】：
我正在尝试在我的 Android 手机上创建一个简单的 BLE 应用程序。 我已经尝试了很多没有成功的例子，我必须忘记一些东西。 希望你能帮助我。 首先你会发现添加的权限，然后是我的简单活动
权限：
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/>
还有我的活动： 两个按钮，一个用于执行扫描，另一个用于停止它。 我想检测一个 BLE 设备，但我的代码从来没有检测到任何东西。
public class MainActivity extends AppCompatActivity {
BluetoothManager btManager;
BluetoothAdapter btAdapter;
BluetoothLeScanner btScanner;
Button startScanningButton;
Button stopScanningButton;
TextView peripheralTextView;
private final static int REQUEST_ENABLE_BT = 1;
private static final int PERMISSION_REQUEST_COARSE_LOCATION = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
peripheralTextView = (TextView) findViewById(R.id.PeripheralTextView);
peripheralTextView.setMovementMethod(new ScrollingMovementMethod());
startScanningButton = (Button) findViewById(R.id.StartScanButton);
startScanningButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
startScanning();
}
});
stopScanningButton = (Button) findViewById(R.id.StopScanButton);
stopScanningButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
stopScanning();
}
});
stopScanningButton.setVisibility(View.INVISIBLE);
btManager = (BluetoothManager)getSystemService(Context.BLUETOOTH_SERVICE);
btAdapter = BluetoothAdapter.getDefaultAdapter();
if ( btAdapter == null ) {
Toast.makeText(
this,
"Bluetooth not supported on this deveice",
Toast.LENGTH_LONG).show();
return;
}
btScanner = btAdapter.getBluetoothLeScanner();
btScanner = BluetoothAdapter.getDefaultAdapter().getBluetoothLeScanner();
// Ensures Bluetooth is available on the device and it is enabled. If not,
// displays a dialog requesting user permission to enable Bluetooth.
if (btAdapter == null || !btAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
if ( ! btAdapter.isEnabled() ) {
// Demande à activer l'interface bluetooth
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
if ( checkSelfPermission( Manifest.permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED ) {
requestPermissions(
new String[] { android.Manifest.permission.ACCESS_COARSE_LOCATION },
456 );
}
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
finish();
}
if (btAdapter != null && !btAdapter.isEnabled()) {
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent,REQUEST_ENABLE_BT);
}
if (this.checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("This app needs location access");
builder.setMessage("Please grant location access so this app can detect peripherals.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);
}
});
builder.show();
}
}
private ScanCallback leScanCallback = new ScanCallback() {
@Override
public void onScanResult(int callbackType, ScanResult result) {
peripheralTextView.append("Device Name: " + result.getDevice().getName() + " rssi: " + result.getRssi() + "\n");
super.onScanResult(callbackType, result);
final int scrollAmount = peripheralTextView.getLayout().getLineTop(peripheralTextView.getLineCount()) - peripheralTextView.getHeight();
if (scrollAmount > 0)
peripheralTextView.scrollTo(0, scrollAmount);
}
};
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_COARSE_LOCATION: {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
System.out.println("coarse location permission granted");
} else {
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Functionality limited");
builder.setMessage("Since location access has not been granted, this app will not be able to discover beacons when in the background.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
}
});
builder.show();
}
return;
}
}
}
private boolean mScanning = false;
private Handler handler = new Handler();
private static final long SCAN_PERIOD = 30000;
public void startScanning() {
System.out.println("start scanning");
peripheralTextView.setText("");
startScanningButton.setVisibility(View.INVISIBLE);
stopScanningButton.setVisibility(View.VISIBLE);
if (!mScanning) {
// Stops scanning after a pre-defined scan period.
handler.postDelayed(new Runnable() {
@Override
public void run() {
mScanning = false;
btScanner.stopScan(leScanCallback);
System.out.println("stop scanning");
}
}, SCAN_PERIOD);
mScanning = true;
btScanner.startScan(leScanCallback);
System.out.println("restart scanning");
} else {
mScanning = false;
btScanner.stopScan(leScanCallback);
System.out.println("stop scanning");
}
}
public void stopScanning() {
System.out.println("stopping scanning");
peripheralTextView.append("Stopped Scanning");
startScanningButton.setVisibility(View.VISIBLE);
stopScanningButton.setVisibility(View.INVISIBLE);
AsyncTask.execute(new Runnable() {
@Override
public void run() {
btScanner.stopScan(leScanCallback);
}
});
}
}
我从不扫描任何东西.. 完全是新手，非常感谢您的帮助。
问候
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标签： android bluetooth-lowenergy