Android 通过BLE播放音乐
我正在构建一个Android音乐播放器，它由通过BLE接收的消息控制。我的应用程序在API 4.4（18）上运行良好，但在8.1（27）中崩溃，可能是因为线程处理不好。这是我的扫描活动和音乐播放器活动，以及来自LogCat的错误 扫描活动Android 通过BLE播放音乐,android,multithreading,bluetooth-lowenergy,bluetooth-gatt,Android,Multithreading,Bluetooth Lowenergy,Bluetooth Gatt,我正在构建一个Android音乐播放器，它由通过BLE接收的消息控制。我的应用程序在API 4.4（18）上运行良好，但在8.1（27）中崩溃，可能是因为线程处理不好。这是我的扫描活动和音乐播放器活动，以及来自LogCat的错误 扫描活动 public class MainActivity extends Activity { private BluetoothAdapter mBluetoothAdapter; private static final int REQUEST_ENABLE_B
public class MainActivity extends Activity {
private BluetoothAdapter mBluetoothAdapter;
private static final int REQUEST_ENABLE_BT = 1;
private static final long SCAN_PERIOD = 3000;
private Dialog mDialog;
public static final int permconst=7;
public static List<BluetoothDevice> mDevices = new ArrayList<BluetoothDevice>();
public static MainActivity instance = null;
private View mPermissionRationale;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.main);
checkperms();
if (!getPackageManager().hasSystemFeature(
PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, "Ble not supported", Toast.LENGTH_SHORT)
.show();
finish();
}
final BluetoothManager mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
Toast.makeText(this, "Ble not supported", Toast.LENGTH_SHORT)
.show();
finish();
return;
}
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
ImageButton btn = (ImageButton) findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
scanLeDevice();
showRoundProcessDialog(MainActivity.this, R.layout.loading_process_dialog_anim);
Timer mTimer = new Timer();
mTimer.schedule(new TimerTask() {
@Override
public void run() {
Intent deviceListIntent = new Intent(getApplicationContext(),
Device.class);
startActivity(deviceListIntent);
mDialog.dismiss();
}
}, SCAN_PERIOD);
}
});
//scanLeDevice();
showRoundProcessDialog(MainActivity.this, R.layout.loading_process_dialog_anim);
Timer mTimer = new Timer();
mTimer.schedule(new TimerTask() {
@Override
public void run() {
Intent deviceListIntent = new Intent(getApplicationContext(),
Device.class);
startActivity(deviceListIntent);
mDialog.dismiss();
}
}, SCAN_PERIOD);
instance = this;
}
public void showRoundProcessDialog(Context mContext, int layout) {
DialogInterface.OnKeyListener keyListener = new DialogInterface.OnKeyListener() {
@Override
public boolean onKey(DialogInterface dialog, int keyCode,
KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_HOME
|| keyCode == KeyEvent.KEYCODE_SEARCH) {
return true;
}
return false;
}
};
mDialog = new AlertDialog.Builder(mContext).create();
mDialog.setOnKeyListener(keyListener);
mDialog.show();
// 娉ㄦ��姝ゅ��瑕���惧��show涔���� ������浼���ュ��甯�
mDialog.setContentView(layout);
}
private void scanLeDevice() {
//checkperms();
// new Thread() {
final Handler handler =new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
// if(Build.VERSION.SDK_INT>21){
// mBluetoothAdapter.getBluetoothLeScanner().startScan(mleScanCallback);}
mBluetoothAdapter.startLeScan(mLeScanCallback);
}
},4000);
mBluetoothAdapter.stopLeScan(mLeScanCallback);
}
private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, final int rssi,
byte[] scanRecord) {
runOnUiThread(new Runnable() {
// new Thread(){
@Override
public void run() {
if (device != null) {
if (mDevices.indexOf(device) == -1)
mDevices.add(device);
}
}
});
}
};
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// User chose not to enable Bluetooth.
if (requestCode == REQUEST_ENABLE_BT
&& resultCode == Activity.RESULT_CANCELED) {
finish();
return;
}
super.onActivityResult(requestCode, resultCode, data);
}
@Override
protected void onDestroy() {
super.onDestroy();
//scanLeDevice(false);
mDevices.clear();
System.exit(0);
}
private void checkperms(){
if(Build.VERSION.SDK_INT>19) {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED){
Toast.makeText(this, "permissions not granted", Toast.LENGTH_SHORT)
.show();
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_COARSE_LOCATION))
Toast.makeText(this, "pls grant permissions", Toast.LENGTH_SHORT)
.show();
else {
// No explanation needed; request the permission
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
permconst);
return;}
}}}}
我有单独的类，其中包含BLE常量和由扫描活动（主活动）填充的蓝牙设备列表。如果目标API级别高于22，请尝试在清单中添加以下权限。新版本需要粗略位置权限（访问蜂窝位置信息）如果要使用蓝牙硬件。这没有意义，但在新的API级别中需要它
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-feature android:name="android.hardware.bluetooth_le"
您是否尝试获取运行时权限
请看链接。您可以休假运行时权限并解决问题。所有权限都存在于清单中，并已在应用程序中签入，但谢谢！
com.example.parlatas.messages I/AndroidRuntime: VM exiting with result code 0, cleanup skipped.
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-feature android:name="android.hardware.bluetooth_le"