我正在编写一个简单的蓝牙客户端,通过 RFCOMM 作为串行端口发送和接收文本消息。我查看了 Android SDK 教程并以相同的方式完成了它:一个 Activity 调用一个线程来建立连接,一旦完成,另一个线程来处理消息接收。
我正在尝试连接到 Parallax EasyBluetooth。计算机和 EasyBT 之间以及基于 Java 的手机和 EasyBT 之间的连接工作正常。所以问题肯定出在代码上,或者我希望不是出在 Android 移动蓝牙芯片上。无论如何,它会打开和关闭,并在扫描时检测其他设备,所以我想问题只是我的编码。
问题是代码卡在 connect() 方法上。所以让我们看看有没有人知道为什么。
活动的 XML 很简单:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/boton"
android:id="@+id/boton_enviar"
/>
</LinearLayout>
当然我已经在Manifyst中添加了蓝牙权限:
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
代码如下:
package uniovi.PFC;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
public class PruebaBTActivity extends Activity {
private String TAG = "pruebaBT";
private BluetoothAdapter mBluetoothAdapter;
private Map<String, BluetoothDevice> mArrayAdapter;
private ConnectedThread hiloEscuchas;
private ConnectThread hiloConectando;
private Handler mHandler;
private Button botonEnviar;
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private static final int REQUEST_ENABLE_BT = 1;
private static final int MESSAGE_READ = 1;
private byte bytes_enviar[];
private String cmd;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Log.d(TAG, "On create abriendo");
mArrayAdapter = new HashMap<String, BluetoothDevice>();
botonEnviar = (Button)findViewById(R.id.boton_enviar);
botonEnviar.setEnabled(false);
botonEnviar.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
cmd = "A";
bytes_enviar = cmd.getBytes();
hiloEscuchas.write(bytes_enviar);
}
});
Log.d(TAG, "On create cerrando");
}
@Override
public void onResume() {
super.onResume();
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
Log.d(TAG, "Device does not support Bluetooth");
}
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
Set<BluetoothDevice> 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.put(device.getName(), device);
}
}
BluetoothDevice device = mArrayAdapter.get("EasyBT");
hiloConectando = new ConnectThread(device);
hiloConectando.run();
//while(hiloEscuchas.isConnected()==false);
//botonEnviar.setEnabled(true);
}
private class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
// Use a temporary object that is later assigned to mmSocket,
// because mmSocket is final
BluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) { }
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
mBluetoothAdapter.cancelDiscovery();
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
} catch (IOException closeException) { }
return;
}
// Do work to manage the connection (in a separate thread)
hiloEscuchas = new ConnectedThread(mmSocket);
hiloEscuchas.run();
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private boolean conectado;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
conectado = false;
mHandler = new Handler();
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
conectado = true;
}
public boolean isConnected(){
return conectado;
}
public void run() {
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
try {
cmd = "A";
bytes_enviar = cmd.getBytes();
hiloEscuchas.write(bytes_enviar);
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI Activity
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
break;
}
}
}
/* Call this from the main Activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) { }
}
/* Call this from the main Activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
}
有一些代码可以对设备进行蓝牙扫描,但为了让事情变得简单直到它起作用,我手动将 MAC 地址写入变量中。评论解释了这一点,也显示了它被卡住的地方。
谢谢
我认为这些至少导致了你的部分问题:
hiloConectando = new ConnectThread(device);
hiloConectando.run();
和
hiloEscuchas = new ConnectedThread(mmSocket);
hiloEscuchas.run();
您应该拨打
start()
,而不是 run()
,例如:
hiloConectando = new ConnectThread(device);
hiloConectando.start();