服务
package com.example.deneme312;
import java.util.ArrayList;
import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothAdapter.LeScanCallback;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.content.Context;
import android.content.Intent;
import android.os.Binder;
import android.os.Handler;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;
public class mservice extends Service implements LeScanCallback {
private static String mBluetoothDeviceAddress = null;
private ArrayList<BluetoothDevice> mDevices= new ArrayList<BluetoothDevice>();
private BluetoothGatt mConnectedGatt;
private BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
private BluetoothGatt mBluetoothGatt;
private static int mConnectionState;
private static final int STATE_DISCONNECTED = 0;
private static final int STATE_CONNECTING = 1;
private static final int STATE_CONNECTED = 2;
private static final int REQUEST_ENABLE_BT = 0;
private static final Handler mHandler = null;
public void startscanning (){
mHandler.post(mStartRunnable);
mHandler.postDelayed(mStopRunnable, 3000);
}
Handler mhandler = new Handler();
private final IBinder mBinder = new LocalBinder();
public class LocalBinder extends Binder {
mservice getService() {
// Return this instance of LocalService so clients can call public
// methods
return mservice.this;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public void onCreate() {
mBluetoothManager=(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter= mBluetoothManager.getAdapter();
super.onCreate();
}
@Override
public void onRebind(Intent intent) {
// TODO Auto-generated method stub
super.onRebind(intent);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
}
@Override
public boolean onUnbind(Intent intent) {
// TODO Auto-generated method stub
return super.onUnbind(intent);
}
final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status,
int newState) {
// TODO Auto-generated method stub
super.onConnectionStateChange(gatt, status, newState);
if (newState == BluetoothProfile.STATE_CONNECTED) {
Toast.makeText(getApplicationContext(), "baglanti kuruldu", Toast.LENGTH_SHORT).show();
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
Toast.makeText(getApplicationContext(), "baglanti kesildi", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
// TODO Auto-generated method stub
super.onServicesDiscovered(gatt, status);
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic, int status) {
// TODO Auto-generated method stub
super.onCharacteristicRead(gatt, characteristic, status);
}
@Override
public void onCharacteristicWrite(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic, int status) {
// TODO Auto-generated method stub
super.onCharacteristicWrite(gatt, characteristic, status);
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic) {
// TODO Auto-generated method stub
super.onCharacteristicChanged(gatt, characteristic);
Toast.makeText(getApplicationContext(), "char changed", Toast.LENGTH_SHORT).show();
}
@Override
public void onDescriptorRead(BluetoothGatt gatt,
BluetoothGattDescriptor descriptor, int status) {
// TODO Auto-generated method stub
super.onDescriptorRead(gatt, descriptor, status);
}
@Override
public void onDescriptorWrite(BluetoothGatt gatt,
BluetoothGattDescriptor descriptor, int status) {
// TODO Auto-generated method stub
super.onDescriptorWrite(gatt, descriptor, status);
}
@Override
public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
// TODO Auto-generated method stub
super.onReliableWriteCompleted(gatt, status);
}
@Override
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
// TODO Auto-generated method stub
super.onReadRemoteRssi(gatt, rssi, status);
}
};
private Runnable mStopRunnable = new Runnable() {
@Override
public void run() {
stopScan();
}
};
private Runnable mStartRunnable = new Runnable() {
@Override
public void run() {
startScan();
}
};
public void startScan() {
mBluetoothAdapter.startLeScan(this);
}
public void stopScan() {
mBluetoothAdapter.stopLeScan(this);
}
@Override
public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
stopScan();
connect(device.getName());
}
public boolean connect(final String address) {
String TAG="connecting situation";
if (mBluetoothAdapter == null || address == null) {
Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
return false;
}
// Previously connected device. Try to reconnect.
if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress)
&& mBluetoothGatt != null) {
Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
if (mBluetoothGatt.connect()) {
mConnectionState = STATE_CONNECTING;
return true;
} else {
return false;
}
}
final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
if (device == null) {
Log.w(TAG, "Device not found. Unable to connect.");
return false;
}
// We want to directly connect to the device, so we are setting the autoConnect
// parameter to false.
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
Log.d(TAG, "Trying to create a new connection.");
mBluetoothDeviceAddress = address;
mConnectionState = STATE_CONNECTING;
return true;
}
}
活性
package com.example.deneme312;
import com.example.deneme312.mservice.LocalBinder;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothManager;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity implements OnClickListener {
private static final String TAG = null;
Button mb;
private boolean mBound1;
mservice mService;
boolean mBound = false;
int clc = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mb = (Button) findViewById(R.id.start_fragment);
mb.setOnClickListener(this);
}
@Override
protected void onStart() {
super.onStart();
// Bind to LocalService
Intent intent = new Intent(this, mservice.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (v.getId() == R.id.start_fragment) {
mService.startscanning();
}
}
/** Defines callbacks for service binding, passed to bindService() */
private ServiceConnection mConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName className, IBinder service) {
// We've bound to LocalService, cast the IBinder and get
// LocalService instance
LocalBinder binder = (LocalBinder) service;
mService = binder.getService();
mBound1 = true;
}
@Override
public void onServiceDisconnected(ComponentName arg0) {
mBound1 = false;
}
};
@Override
protected void onStop() {
super.onStop();
// Unbind from the service
if (mBound1) {
unbindService(mConnection);
mBound1 = false;
}
}
}
现在这里的代码不起作用。有一些活动绑定了一个服务，并从服务中调用一个函数（startscanning），试图从那个服务中找到可用的设备，并且它对于那些类型的任何想法都是错误的。错误????在此先感谢
11-19 11:30:47.275: E/AndroidRuntime(27612): FATAL EXCEPTION: main
11-19 11:30:47.275: E/AndroidRuntime(27612): java.lang.NullPointerException
11-19 11:30:47.275: E/AndroidRuntime(27612): at com.example.deneme312.mservice.startscanning(mservice.java:43)
11-19 11:30:47.275: E/AndroidRuntime(27612): at com.example.deneme312.MainActivity.onClick(MainActivity.java:55)
11-19 11:30:47.275: E/AndroidRuntime(27612): at android.view.View.performClick(View.java:4475)
11-19 11:30:47.275: E/AndroidRuntime(27612): at android.view.View$PerformClick.run(View.java:18786)
11-19 11:30:47.275: E/AndroidRuntime(27612): at android.os.Handler.handleCallback(Handler.java:730)
11-19 11:30:47.275: E/AndroidRuntime(27612): at android.os.Handler.dispatchMessage(Handler.java:92)
11-19 11:30:47.275: E/AndroidRuntime(27612): at android.os.Looper.loop(Looper.java:176)
11-19 11:30:47.275: E/AndroidRuntime(27612): at android.app.ActivityThread.main(ActivityThread.java:5419)
11-19 11:30:47.275: E/AndroidRuntime(27612): at java.lang.reflect.Method.invokeNative(Native Method)
11-19 11:30:47.275: E/AndroidRuntime(27612): at java.lang.reflect.Method.invoke(Method.java:525)
11-19 11:30:47.275: E/AndroidRuntime(27612): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
11-19 11:30:47.275: E/AndroidRuntime(27612): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
11-19 11:30:47.275: E/AndroidRuntime(27612): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
您正在使用静态变量mHandler
private static final Handler mHandler = null; // H is caps
再次初始化另一个变量
Handler mhandler = new Handler(); // h is small letter
删除 private static final Handler mHandler = null;
并使用以下代码
Handler mhandler = new Handler();
public void startscanning (){
mhandler.post(mStartRunnable);
mhandler.postDelayed(mStopRunnable, 3000);
}