Android BluetoothLeScanner开始扫描仅转到错误代码2
我在手机上打开了蓝牙,我的手机是最新版本的galaxy s8。 不明白什么我无法在回拨时获得蓝牙4.0设备 下面是代码片段Android BluetoothLeScanner开始扫描仅转到错误代码2,android,bluetooth,energy,Android,Bluetooth,Energy,我在手机上打开了蓝牙,我的手机是最新版本的galaxy s8。 不明白什么我无法在回拨时获得蓝牙4.0设备 下面是代码片段 public class MainActivity extends AppCompatActivity { private BluetoothLeScanner mBLEScanner; BluetoothAdapter mBluetoothAdapter; private static final long SCAN_PERIOD = 5000; Handler mHa
public class MainActivity extends AppCompatActivity {
private BluetoothLeScanner mBLEScanner;
BluetoothAdapter mBluetoothAdapter;
private static final long SCAN_PERIOD = 5000;
Handler mHandler=null;
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
checkPermission();
BluetoothAdapter bluetoothAdapter =
BluetoothAdapter.getDefaultAdapter();
if(!bluetoothAdapter.isEnabled()){
bluetoothAdapter.enable();
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mBLEScanner=bluetoothAdapter.getBluetoothLeScanner();
}
mHandler = new Handler();
btn=(Button)findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.e("main","now calling bluetooth low energy");
scanLeDevice(true);
}
});
}
void checkPermission(){
String[] permissions = {
Manifest.permission.INTERNET,
Manifest.permission.ACCESS_NETWORK_STATE,
Manifest.permission.BLUETOOTH_ADMIN,
Manifest.permission.BLUETOOTH,
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION,
};
int permissionCheck = PackageManager.PERMISSION_GRANTED;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[].
{Manifest.permission.READ_PHONE_STATE}, 0);
requestPermissions(new String[]
{Manifest.permission.ACCESS_COARSE_LOCATION}, 1);
}
for (int i = 0; i < permissions.length; i++) {
permissionCheck = ContextCompat.checkSelfPermission(this,
permissions[i]);
if (permissionCheck == PackageManager.PERMISSION_DENIED) {
Log.e("main", "denied" + permissions[i]);
ActivityCompat.requestPermissions(this, permissions, i);
if
(ActivityCompat.shouldShowRequestPermissionRationale(this,
permissions[i])) {
Log.e("main", "shouldshow" + permissions[i]);
} else {
Log.e("main", "requesting" + permissions[i]);
ActivityCompat.requestPermissions(this, permissions, i);
}
break;
} else {
Log.e("main", "granted" + permissions[i]);
}
}
}
@TargetApi(21)
private void scanLeDevice(final boolean enable) {
if (enable) {
//stops scanning after a pre-defined scan period
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
if (Build.VERSION.SDK_INT < 21) {
System.out.println("BLE// mBluetoothAdapter.stopLeScan(mLeScanCallback) ");
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mBLEScanner.stopScan(mScanCallback);
System.out.println("BLE// mLEScanner.stopScan(mScanCallback) ");
}
}
}, SCAN_PERIOD);
if (Build.VERSION.SDK_INT < 21) {
System.out.println("BLE// mBluetoothAdapter.startLeScan(mLeScanCallback)");
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
Log.e("main","starting scan for second"+mBLEScanner);
mBLEScanner.startScan(mScanCallback);
//mLEScanner.startScan(filters, settings, mScanCallback);
}
} else {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mBLEScanner.stopScan(mScanCallback);
}
}
}
private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi,
byte[] scanRecord) {
}
};
private ScanCallback mScanCallback = new ScanCallback() {
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
public void onScanResult(int callbackType, ScanResult result) {
super.onScanResult(callbackType, result);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
Log.e("main","this name : "+result.getDevice().getName());
Log.e("main","this addr : "+result.getDevice().getAddress());
}
BluetoothDevice btDevice = result.getDevice();
}
@Override
public void onBatchScanResults(List<ScanResult> results) {
}
@Override
public void onScanFailed(int errorCode) {
Log.e("main", "Error Code: " + errorCode);
}
};
}
清单代码如下所示
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="smartiot.ica.org.mbluetooth">
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<application
您是否在清单中声明了该ST,请从清单中的google中找到它,并添加我刚刚从您的代码中复制的权限
如果不在清单文件中声明,运行时权限将不起作用
Manifest.permission.INTERNET,
Manifest.permission.ACCESS_NETWORK_STATE,
Manifest.permission.BLUETOOTH_ADMIN,
Manifest.permission.BLUETOOTH,
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION,
您应在运行时通过以下方式请求启用蓝牙适配器:
private void sendenablerequestintent(){
Intent enablebintent=新意图(BluetoothAdapter.ACTION\u REQUEST\u ENABLE);
startActivityForResult(启用BTIntent、请求\启用\ BT);
}
在此处捕获startActivityForResult响应:
@覆盖
ActivityResult上的公共void(int请求代码、int结果代码、意图数据){
super.onActivityResult(请求代码、结果代码、数据);
if(requestCode==请求\启用\ BT&&resultCode==结果\确定){
//你的东西在这里
}
}
它显示有关清单的信息。也发布清单代码。是的,当然:)并且正如日志在最后所说,除了访问位置之外,所有权限都被授予。但不知道为什么…请求的价值是什么????如何在代码中定义它?您可以定义任意的int值,它只是一个标识onActivity结果方法中正确请求的ID。在classNo的顶部定义一个最终的静态常量REQUEST_ENABLE_BT=10(或另一个int)。它仍然有相同的错误代码2。首先…蓝牙是在不使用SendEnableRequestIntent的情况下启用的。。。您是否尝试过我建议的运行时权限请求?正如日志消息所示,除了粗略位置之外,所有权限都已授予……但我认为这无关紧要。
Manifest.permission.INTERNET,
Manifest.permission.ACCESS_NETWORK_STATE,
Manifest.permission.BLUETOOTH_ADMIN,
Manifest.permission.BLUETOOTH,
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION,