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连接的线程返回空对象

android

-1

NetworkStudent · 技术社区 · 7 年前

我正在我的片段上使用蓝牙连接服务,但ConnectedThread返回空虽然我打电话给蓝牙连接服务,但不起作用我找不到解决办法我该怎么解决? 碎片:

if(convertView==null) {
            convertView = inflater.inflate(R.layout.fragment_ota__update, container, false);

            text=(TextView)convertView.findViewById(R.id.text);
            InputStream  is =this.getResources().openRawResource(R.raw.blink);
            BufferedReader reader = new BufferedReader( new InputStreamReader(is));
            send =(Button) convertView.findViewById(R.id.send);
            mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
            IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
            getActivity().registerReceiver(mBroadcastReceiver4, filter);

            mBluetoothConnection = new BluetoothConnectionService(getActivity().getApplicationContext());
            mBluetoothConnection.startClient(mBTDevice,MY_UUID_INSECURE);
            if(is!=null){

                try {
                    while ((data = reader.readLine()) != null) {
                        char [] ch =data.toCharArray();

                        for (char c: ch) {
                            int i= (int) c;
                            sbuffer.append(Integer.toHexString(i).toUpperCase());
                            text.setText(sbuffer);

                        }

                    }

                    is.close();

                }
                 catch (IOException e) {
                    e.printStackTrace();
                }
            }

            send.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if(sbuffer!=null) {

                        byte[] bytes = sbuffer.toString().getBytes(Charset.defaultCharset());
                        mBluetoothConnection.write(bytes);

                    }
                }
            });
        }

在我用以下代码调用的片段中:

  mBluetoothConnection = new BluetoothConnectionService(getActivity().getApplicationContext());

写入函数的蓝牙连接服务部分

public void write(byte[] out) {
        if(mConnectedThread !=null ){
            // Create temporary object


            // Synchronize a copy of the ConnectedThread
            Log.d(TAG, "write: Write Called.");
            //perform the write
            mConnectedThread.write(out);
        }
        else{
            Log.d(TAG, "mConnectedThread empty ");


        }
    }

这是我的蓝牙连接课程: https://paste.ubuntu.com/p/gcPrydZnDw/

1 回复 | 直到 7 年前

CU_dev 7 年前

你的代码不是我能直接修复的。但我这里有一个例子,说明了我如何建立连接,然后将数据发送到这个连接的设备:

public class BluetoothConnection extends Thread {

public static  BluetoothSocket mSocket;

private InputStream mInStream;
private OutputStream mOutStream;
private byte[] buffer;
private BluetoothAdapter mAdapter;
private Handler mHandler;
private String output;
private String sendString;
private String tempTester = "";

static UUID MY_UUID;

/**
 * Constructor initializes all necessary variables.
 * @param device the device that the constructor will connect to
 */
public BluetoothConnection(BluetoothDevice device){
    MY_UUID = device.getUuids()[0].getUuid();
    mAdapter = null;
    mSocket = createMSocket(device);
    mSocket = connectSocket(mSocket);

    InputStream tmpIn = null;
    OutputStream tmpOut = null;
    try{
        tmpIn = mSocket.getInputStream();
        tmpOut = mSocket.getOutputStream();
    }catch (IOException e){
        e.printStackTrace();
    }
    mInStream = tmpIn;
    mOutStream = tmpOut;
    buffer = new byte[25];
}// end constructor

/**
 * Creates the main socket that will be used in connection with device.
 * @param device a BluetoothDevice
 * @return a BluetoothSocket mSocket.
 */
private BluetoothSocket createMSocket(BluetoothDevice device) {
    BluetoothSocket tmp = null;
    try {
        tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return tmp;
}// end createMSocket

/**
 * Socket makes connection to device then returns back the updated socket.
 * @param socket BluetoothSocket
 * @return an updated version of the parameter socket.
 */
private BluetoothSocket connectSocket(BluetoothSocket socket){
    try {
        // This is a blocking call and will only return on a
        // successful connection or an exception
        socket.connect();
        System.out.println("$$$$$$$$$$$$$$$$****** socket connected ******$$$$$$$$$$$$$$$$");
    } catch (IOException e) {
        //connection to device failed so close the socket
        try {
            socket.close();
            System.out.println("$$$$$$$$$$$$$$$$****** socket closed ******$$$$$$$$$$$$$$$$");
        } catch (IOException e2) {
            e2.printStackTrace();
        }
    }
    return socket;
}// end connectSocket

/**
 * Sends message back to device in the form of a byte[].
 * @param buffer byte[]
 */
public void write(byte[] buffer){
    try{
        mOutStream.write(buffer);
    }catch(IOException e) {
        e.printStackTrace();
    }
}// end write


/**
 * Closes the connection with the device
 */
public void cancel(){
    try{
        mSocket.close();
    }catch(IOException e){
        e.printStackTrace();
    }
}// end cancel

}

然后,在活动的主线程上,可以调用以下代码(只要知道要连接的设备):

BluetoothConnection connection = new BluetoothConnection(connectedDevice);

public void sendData(){

   String s = editText.getText().toString();

   byte[] b = s.getBytes();

   connection.write(b);

   //System.out.println("Bytes Sent");
}// end sendData