Базовое приложение Bluetooth не работает

Question

Я хочу реализовать передачу данных с удаленного сервера Bluetooth, поэтому я начал изучать функции андроида Bluetooth, я иду шаг за шагом, теперь я застрял в программе. После загрузки программы в эмулятор он отвечает: «Adil_Bluetooth_1st остановился».

Я предоставить вам мои файлы:

XML файл:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context=".MainActivity" > 

    <TextView 
     android:id="@+id/acceleration" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentTop="true" 
     android:text="X: Y: Z:" 
     android:textAppearance="?android:attr/textAppearanceLarge" /> 

    <ProgressBar 
     android:id="@+id/progressBarX" 
     style="?android:attr/progressBarStyleHorizontal" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignLeft="@+id/acceleration" 
     android:layout_alignParentRight="true" 
     android:layout_below="@+id/acceleration" 
     android:layout_marginLeft="19dp" 
     android:layout_marginRight="19dp" 
     android:layout_marginTop="40dp" /> 

    <TextView 
     android:id="@+id/textView1" 
     android:layout_width="140dp" 
     android:layout_height="wrap_content" 
     android:layout_alignRight="@+id/progressBarX" 
     android:layout_alignTop="@+id/acceleration" 
     android:text="    Noise Margin" /> 

    <TextView 
     android:id="@+id/textView2" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignLeft="@+id/progressBarX" 
     android:layout_below="@+id/progressBarX" 
     android:text="X-axis" /> 

    <TextView 
     android:id="@+id/textView3" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignLeft="@+id/progressBarZ" 
     android:layout_below="@+id/progressBarY" 
     android:text="Y-axis" /> 

    <ProgressBar 
     android:id="@+id/progressBarY" 
     style="?android:attr/progressBarStyleHorizontal" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignLeft="@+id/textView2" 
     android:layout_alignRight="@+id/progressBarX" 
     android:layout_below="@+id/textView2" 
     android:layout_marginTop="72dp" /> 

    <EditText 
     android:id="@+id/eText" 
     android:layout_width="50dp" 
     android:layout_height="45dp" 
     android:layout_alignLeft="@+id/textView1" 
     android:layout_alignTop="@+id/textView1" 
     android:ems="10" 
     android:inputType="numberDecimal" > 

     <requestFocus /> 
    </EditText> 

    <TextView 
     android:id="@+id/textView4" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignLeft="@+id/progressBarZ" 
     android:layout_alignTop="@+id/progressBarZ" 
     android:layout_marginTop="20dp" 
     android:text="Z-axis" /> 

    <ProgressBar 
     android:id="@+id/progressBarZ" 
     style="?android:attr/progressBarStyleHorizontal" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignLeft="@+id/progressBarY" 
     android:layout_alignRight="@+id/progressBarY" 
     android:layout_below="@+id/textView3" 
     android:layout_marginTop="84dp" /> 

</RelativeLayout> 

И это мой ActivityMain.java файл:

package com.example.adil_bluetooth_1st; 

import java.util.Set; 

import javax.xml.datatype.Duration; 

import android.os.Bundle; 
import android.app.Activity; 
import android.view.Menu; 
import android.widget.ArrayAdapter; 
import android.widget.Toast; 
import android.bluetooth.*; 
import android.content.BroadcastReceiver; 
import android.content.Context; 
import android.content.Intent; 
import android.content.IntentFilter; 

public class Bluetooth extends Activity { 

    private BluetoothAdapter mBluetoothAdapter; 
    Integer REQ_BT_ENABLE=1; 
    private ArrayAdapter<String> mArrayAdapter; 
    Set<BluetoothDevice> pairedDevices; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_bluetooth); 
     mBluetoothAdapter=BluetoothAdapter.getDefaultAdapter(); 
     String Status; 
     if(mBluetoothAdapter==null) 
     { 
      Toast.makeText(this, "Device doesn't support Bluetooth", Toast.LENGTH_LONG).show(); 

     } 
     /* 
     * checking whether Bluetooth is enabled ,if not enable it! 
     * */ 
     if(mBluetoothAdapter.isEnabled()) 
     { 
      String mydeviceadress=mBluetoothAdapter.getAddress(); 
      String mydevicename=mBluetoothAdapter.getName(); 
      Status="My Device Name is:"+mydevicename+"\nThe Adress is:"+mydeviceadress; 
      Toast.makeText(this, Status, Toast.LENGTH_LONG).show(); 
     } 
     else 
     { 
      Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); 
      startActivityForResult(enableBtIntent, REQ_BT_ENABLE); 
      Toast.makeText(this, "Enabling Bluetooth!!", Toast.LENGTH_LONG).show(); 
     } 
     /* 
     * Getting paired devices and saving them on an ArrayAdapter 
     * */ 
     pairedDevices = mBluetoothAdapter.getBondedDevices(); 
     // If there are paired devices 
     if (pairedDevices.size() > 0) { 
      // Loop through paired devices 
      for (BluetoothDevice device : pairedDevices) { 
       // Add the name and address to an array adapter to show in a ListView 
       mArrayAdapter.add(device.getName() + "\n" + device.getAddress()); 
      } 
     } 
     /*Create a BroadcastReceiver for ACTION_FOUND 
     * 
     * */ 


     final BroadcastReceiver Receiver = new BroadcastReceiver() { 
      public void onReceive(Context context, Intent intent) { 
       String action = intent.getAction(); 
       // When discovery finds a device 
       if (BluetoothDevice.ACTION_FOUND.equals(action)) { 
        // Get the BluetoothDevice object from the Intent 
        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); 
        // Add the name and address to an array adapter to show in a ListView 
        mArrayAdapter.add(device.getName() + "\n" + device.getAddress()); 
       } 
      } 
     }; 
     // Register the BroadcastReceiver 
     IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); 
     registerReceiver(Receiver, filter); 


     /* 
     * to make the device discoverable 
     * */ 
     Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); 
     discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300); 
     startActivity(discoverableIntent); 

    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.bluetooth, menu); 
     return true; 
    } 

} 

LogCat сообщения:

> 04-04 16:41:58.051: E/BluetoothAdapter(1082): Bluetooth binder is null 
> 04-04 16:41:58.111: D/AndroidRuntime(1082): Shutting down VM 04-04 
> 16:41:58.111: W/dalvikvm(1082): threadid=1: thread exiting with 
> uncaught exception (group=0x40a71930) 04-04 16:41:58.131: 
> E/AndroidRuntime(1082): FATAL EXCEPTION: main 04-04 16:41:58.131: 
> E/AndroidRuntime(1082): java.lang.RuntimeException: Unable to start 
> activity 
> 

ComponentInfo{com.example.adil_bluetooth_1st/com.example.adil_bluetooth_1st.Bluetooth}: 
> java.lang.NullPointerException 04-04 16:41:58.131: 
> E/AndroidRuntime(1082): at 
> android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180) 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): at 
> android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230) 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): at 
> android.app.ActivityThread.access$600(ActivityThread.java:141) 04-04 
> 16:41:58.131: E/AndroidRuntime(1082):  at 
> android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): at 
> android.os.Handler.dispatchMessage(Handler.java:99) 04-04 
> 16:41:58.131: E/AndroidRuntime(1082):  at 
> android.os.Looper.loop(Looper.java:137) 04-04 16:41:58.131: 
> E/AndroidRuntime(1082): at 
> android.app.ActivityThread.main(ActivityThread.java:5041) 04-04 
> 16:41:58.131: E/AndroidRuntime(1082):  at 
> java.lang.reflect.Method.invokeNative(Native Method) 04-04 
> 16:41:58.131: E/AndroidRuntime(1082):  at 
> java.lang.reflect.Method.invoke(Method.java:511) 04-04 16:41:58.131: 
> E/AndroidRuntime(1082): at 
> com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): at 
> com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 04-04 
> 16:41:58.131: E/AndroidRuntime(1082):  at 
> dalvik.system.NativeStart.main(Native Method) 04-04 16:41:58.131: 
> E/AndroidRuntime(1082): Caused by: java.lang.NullPointerException 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): at 
> com.example.adil_bluetooth_1st.Bluetooth.onCreate(Bluetooth.java:38) 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): at 
> android.app.Activity.performCreate(Activity.java:5104) 04-04 
> 16:41:58.131: E/AndroidRuntime(1082):  at 
> android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): at 
> android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144) 
> 04-04 16:41:58.131: E/AndroidRuntime(1082): ... 11 more 

Answer 1

Аналогичная проблема здесь ответа на Waqas

Ваш [Bluetooth] услуга не может быть пустым, так как связывание службы является асинхронный метод