我不擅长英语:( 请理解我。
我有两部智能手机。一个是Android 4.4.4版，支持蓝牙4.0。另一个是Android 7.0版，支持蓝牙4.1。我编写了代码来扫描蓝牙。但是，当我在智能手机（即）7.0版的Android上扫描蓝牙时，会发出一条消息＆＃34;没有找到任何设备＆＃34;出现。我对两者都使用相同的代码，我不知道7.0版为什么不扫描蓝牙
MainActivity调用BluetoothSevice，它提供蓝牙服务，ScanDevice函数调用DeviceListActivity到BluetoothSevice。我认为扫描功能在DeviceListActivity中，所以我认为仅仅看到DeviceListActivity就足够了。
的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.hansung.bluetooth4">
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".DeviceListActivity"
android:theme="@android:style/Theme.DeviceDefault.Dialog">
</activity>
</application>
</manifest>
MainActivity.java
public class MainActivity extends AppCompatActivity {
//debugging
private static final String TAG = "Main";
//Intent request code
private static final int REQUEST_CONNECT_DEVICE = 1;
private static final int REQUEST_ENABLE_BT=2;
private Button btn_Connect;
private BluetoothService bluetoothService_obj = null;
private final Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
super.handleMessage(msg);
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.e(TAG,"onCreate");
setContentView(R.layout.activity_main);
if(bluetoothService_obj==null){
bluetoothService_obj = new BluetoothService(this,mHandler);
}
if(bluetoothService_obj.getDeviceState())
{
bluetoothService_obj.enableBluetooth();
}
else
{
finish();
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
Log.d(TAG, "onActivityResult입니다. resultCode : " + resultCode);
// TODO Auto-generated method stub
switch(requestCode)
{
case REQUEST_ENABLE_BT: //블루투스가 비활성화 됬음을 확인했을 경우.활성화 요청
//When the request to enable Bluetooth returns
if(resultCode == Activity.RESULT_OK)
{
bluetoothService_obj.scanDevice();
}else{
Log.d(TAG, "cancel");
}
break;
case REQUEST_CONNECT_DEVICE:
if(resultCode==Activity.RESULT_OK)
{
//bluetoothService_obj.getDevifeInfo(data);
}
break;
}
}
}
BluetoothService.java
public class BluetoothService {
//Intent request code
private static final int REQUEST_CONNEXT_DEVICE =1;
private static final int REQUEST_ENABLE_BT=2;
//Debugging
private static final String TAG = "BluetoothService";
//RFCOMM Protocol
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private BluetoothAdapter btAdapter;
private Activity mActivity;
private Handler mHandler;
public BluetoothService(Activity activity, Handler handler)
{
mActivity = activity;
mHandler = handler;
btAdapter = BluetoothAdapter.getDefaultAdapter();
}
public boolean getDeviceState()
{
Log.d(TAG, "check Bluetooth enable");
if(btAdapter==null)
{
Log.d(TAG, "You can't use Bluetooth ");
return false;
}
else
{
Log.d(TAG, "You can use Bluetooth");
return true;
}
}
public void enableBluetooth()
{
Log.i(TAG, "블루투스 활성화 여부 확인");
if(btAdapter.isEnabled())
{
Log.d(TAG, "Bluetooth enable");
scanDevice();
}
else
{
Log.d(TAG, "Bluetooth doesn't enable");
Intent i = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
mActivity.startActivityForResult(i, REQUEST_ENABLE_BT);
}
}
public void scanDevice(){
Log.d(TAG,"Scan Device");
Intent serverIntent = new Intent(mActivity, DeviceListActivity.class);
mActivity.startActivityForResult(serverIntent,REQUEST_CONNEXT_DEVICE);
}
}
DeviceListActivity.java
package com.example.hansung.bluetooth4;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
public class DeviceListActivity extends Activity {
private static final String TAG = "DeviceListActivity";
private BluetoothAdapter mBtAdapter;
private ArrayAdapter<String> mNewDevicesArrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.activity_device_list);
setResult(Activity.RESULT_CANCELED);
Button scanButton = (Button) findViewById(R.id.button_scan);
scanButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (mBtAdapter.isDiscovering()) {
mBtAdapter.cancelDiscovery();
}
mBtAdapter.startDiscovery();
v.setVisibility(View.GONE);
}
});
mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(mReceiver, filter);
mBtAdapter = BluetoothAdapter.getDefaultAdapter();
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
short rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,Short.MAX_VALUE);
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress()+"(RSSI: "+rssi+"dBm)");
}
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
setProgressBarIndeterminateVisibility(false);
setTitle(R.string.select_device);
if (mNewDevicesArrayAdapter.getCount() == 0) {
String noDevices = getResources().getText(R.string.none_found).toString();
mNewDevicesArrayAdapter.add(noDevices);
}
}
}
};
}