我正在使用蓝牙设备。基本上我希望我的应用程序连接到设备并接收它发送的数据。但到目前为止，我能够连接到蓝牙设备，但我无法从它接收任何输入。
这是我的问题：
i）DataInputStream.available（）始终返回0.
ii）如果我在线使用任何断点 bytes = input.read（buffer）; //这将冻结并不显示任何内容。 它下面的行永远不会执行
public class ConnectThread extends Thread{
final String TAG="ConnectThread";
private ReadThread mReadThread = null;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private boolean isDeviceConnected;
public final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private BluetoothSocket mmSocket = null;
Handler mHandler;
BluetoothDevice bTdevice;
private DataInputStream mReadData = null;
public ConnectThread(BluetoothDevice bTdevice, Handler mHandler) {
super();
this.bTdevice = bTdevice;
this.mHandler = mHandler;
InputStream tmpIn = null;
OutputStream tmpOut = null;
BluetoothSocket socket;
try {
socket = bTdevice.createRfcommSocketToServiceRecord(MY_UUID);
System.out.println("**** Socket created using standard way******");
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
mmSocket = socket;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
@Override
public synchronized void run() {
// TODO Auto-generated method stub
super.run();
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
if (adapter != null) {
adapter.cancelDiscovery();
Log.i("***Bluetooth Adapter**", "Bluetooth Discovery Canceled");
}
if (mmSocket != null) {
mmSocket.connect();
Log.i("***Socket Connection Successful**", "Socket Connection Successful");
isDeviceConnected = true;
mReadData = new DataInputStream(mmSocket.getInputStream());
Log.i("***Read data**", "" + mReadData);
if (mReadThread == null) {
mReadThread=new ReadThread(mReadData,mmSocket);
mReadThread.start();
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e("***Error**", "Socket Connection failed");
e.printStackTrace();
try {
mmSocket.close();
isDeviceConnected = false;
} catch (IOException closeException) {
e.printStackTrace();
}
}
// mHandler.obtainMessage(DisplayBtdataActivity.SUCCESS_CONNECT,mmSocket).sendToTarget();
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
// Read the data from device
private class ReadThread extends Thread {
/** The input. */
private DataInputStream input;
/**
* Constructor for ReadThread.
*
* @param input
* DataInputStream
*/
private BluetoothSocket mSocket;
public ReadThread(DataInputStream input, BluetoothSocket socket) {
this.input = input;
this.mSocket = socket;
}
/**
* Method run.
*
* @see java.lang.Runnable#run()
*/
public synchronized void run() {
try {
Log.d(TAG, "ReadThread run");
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
bytes = input.available(); // always return 0
// bytes = mReadData.readInt();
Log.i("***Bytes data**", "" + bytes);// print 0
Log.i("***Data input stream**", "" + input); // Here input is not null
if (input != null) {
Log.i("***hello world**", "...");
while (isDeviceConnected) {
try {
bytes = input.read(buffer); // this code never executes
Log.i("**bytes data**", " " + bytes);
if (input != null) {
int len = input.readInt();
Log.i(TAG, "Response Length: " + len);
if (len > 65452) {// Short.MAX_VALUE*2
Log.i(TAG, "Error: Accesory and app are not in sync.");
continue;
}
Log.d(TAG, "Response Length: " + len);
Log.d(TAG, "Reading start time:" + System.currentTimeMillis());
byte[] buf = new byte[len];
Log.d(
TAG, "input.available() " + input.available());
if (input.available() > 0) {
input.readFully(buf);
System.out.println("Output:=");
}
Log.d(TAG, "Reading end time:" + System.currentTimeMillis());
}
} catch (Exception e) {
Log.e(TAG, e.getMessage());
isDeviceConnected = false;
}
}
}
} catch (Exception e) {
e.printStackTrace();
isDeviceConnected = false;
Log.e(TAG, "catch block 3 " + e.toString());
}
}
}
}
答案 0 :(得分：1)
在ReadThread.Run() - 您必须移动代码
bytes = input.available (); // Always return 0
进入while循环
1，在检查null input
if (input! = null)
2，数据是连续发送的，很可能在运行线程时没有任何数据，因此你必须将input.available bytes = ();放入while循环中。
3，您可以尝试修改数据处理。原则上，快速读取临时缓冲区中的数据，然后移动到MainBuffer，然后用它进行操作。一个例子是c # .net Xamarin，但仅举例：
private const int BTLPacketSize = 1024;
private const int BTLdataSize = 65536;
private System.Object InternaldataReadLock = new System.Object();
private System.Object dataReadLock = new System.Object();
private byte[] InternaldataRead = new byte[BTLPacketSize];//posila 64Byte pakety (resp. 62, protoze 2 jsou status bytes)
private byte[] TempdataRead = new byte[BTLPacketSize];
private byte[] dataRead = new byte[BTLdataSize];//Tyto pameti pouzivaji cursorc -> musim ohlidat preteceni pameti//Max. prenos rychlost je 115200 b/s.
private bool continueRead = true;
public override void Run()
{
while (continueRead)
{
try
{
int readBytes = 0;
lock (InternaldataReadLock)
{//Quick reads data into bigger InternaldataRead buffer and next move only "received bytes" readBytes into TempdataRead buffer
readBytes = clientSocketInStream.Read(InternaldataRead, 0, InternaldataRead.Length);
Array.Copy(InternaldataRead, TempdataRead, readBytes);
}
if (readBytes > 0)
{//If something reads move it from TempdataRead into main dataRead buffer a send it into MainThread for processing.
lock (dataReadLock)
{
dataRead = new byte[readBytes];
for (int i = 0; i < readBytes; i++)
{
dataRead[i] = TempdataRead[i];
}
}
Bundle dataBundle = new Bundle();
dataBundle.PutByteArray("Data", dataRead);
Message message = btlManager.sourceHandler.ObtainMessage();
message.What = 1;
message.Data = dataBundle;
btlManager.sourceHandler.SendMessage(message);
}
}
catch (System.Exception e)
{
if (e is Java.IO.IOException)
{
//.....
}
}
}
}