如何防止 Android 蓝牙 RFCOMM 连接在 .connect() 后立即死亡？
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How to prevent Android bluetooth RFCOMM connection from dying immediately after .connect()?
提问by Gilead
This problem has been solved! Thanks a lot to Brad, Denis and junkie! You're the heroes! :)
这个问题已经解决了！非常感谢布拉德、丹尼斯和瘾君子！你们是英雄！:)
This is the working code. It connects to Zeemote and reads data from it.
这是工作代码。它连接到 Zeemote 并从中读取数据。
===== Code =====
===== 代码 =====
public class ZeeTest extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
for (int i = 0; i < 3; i++) {
test();
}
} catch (Exception e) {
e.printStackTrace();
}
}
private boolean connected = false;
private BluetoothSocket sock;
private InputStream in;
public void test() throws Exception {
if (connected) {
return;
}
BluetoothDevice zee = BluetoothAdapter.getDefaultAdapter().
getRemoteDevice("00:1C:4D:02:A6:55");
Method m = zee.getClass().getMethod("createRfcommSocket",
new Class[] { int.class });
sock = (BluetoothSocket)m.invoke(zee, Integer.valueOf(1));
Log.d("ZeeTest", "++++ Connecting");
sock.connect();
Log.d("ZeeTest", "++++ Connected");
in = sock.getInputStream();
byte[] buffer = new byte[50];
int read = 0;
Log.d("ZeeTest", "++++ Listening...");
try {
while (true) {
read = in.read(buffer);
connected = true;
StringBuilder buf = new StringBuilder();
for (int i = 0; i < read; i++) {
int b = buffer[i] & 0xff;
if (b < 0x10) {
buf.append("0");
}
buf.append(Integer.toHexString(b)).append(" ");
}
Log.d("ZeeTest", "++++ Read "+ read +" bytes: "+ buf.toString());
}
} catch (IOException e) {}
Log.d("ZeeTest", "++++ Done: test()");
}
@Override
public void onDestroy() {
try {
if (in != null) {
in.close();
}
if (sock != null) {
sock.close();
}
} catch (IOException e) {
e.printStackTrace();
}
super.onDestroy();
}
}
===== Original question =====
======原始问题=====
I'm trying to connect to a Zeemote (http://zeemote.com/) gaming controller from Moto Droid running 2.0.1 firmware. The test application below does connect to the device (LED flashes) but connection is dropped immediately after that.
我正在尝试从运行 2.0.1 固件的 Moto Droid连接到 Zeemote ( http://zeemote.com/) 游戏控制器。下面的测试应用程序确实连接到设备（LED 闪烁），但此后连接立即断开。
I'm pasting two test apps below: one that actually tries to read from input stream and second one that just sits there, waiting for the device to disconnect after 5 seconds. And yes, I do have third version :) which first waits for ACL_CONNECTED and then opens socket but there's nothing new in its behaviour.
我在下面粘贴了两个测试应用程序：一个实际上尝试从输入流中读取，第二个只是坐在那里，等待设备在 5 秒后断开连接。是的，我确实有第三个版本:)，它首先等待 ACL_CONNECTED，然后打开套接字，但它的行为没有任何新内容。
Some background info: I can connect to the Zeemote from my laptop perfectly fine using bluez tools (log attached as well). I know for sure that Droid isable to talk to Zeemote as well because 'Game Pro' from the Market works fine with it (but then it's a driver/service so maybe it uses lower-level API?).
一些背景信息：我可以使用 bluez 工具（也附上日志）从我的笔记本电脑完美地连接到 Zeemote。我确信 Droid也能够与 Zeemote 对话，因为市场上的“Game Pro”可以很好地使用它（但它是一个驱动程序/服务，所以它可能使用较低级别的 API？）。
I noticed that 'adb bugreport' reports neither UUID nor RFCOMM channel for Zeemote while it does so for all other devices (including Moto HS815 headset, another dumb device for which 'sdp browse' reports nothing). Also, when the device boots, Zeemote's priority is 0 (others have priority 100+).
我注意到“adb bugreport”既不报告Zeemote 的UUID 也不报告RFCOMM 通道，而它为所有其他设备（包括Moto HS815 耳机，另一个“sdp 浏览”不报告任何内容的哑设备）报告。此外，当设备启动时，Zeemote 的优先级为 0（其他的优先级为 100+）。
I'm quite at a loss here, I worked on it for so long that I ran out of ideas so any help would be very much appreciated (even if you don't know theanswer :) )
我不知所措我在这儿住，我工作了这么久，我跑的想法说出来，所以任何帮助将是非常赞赏（即使你不知道的答案:)）
Thanks, Max
谢谢，马克斯
Test application No. 1
测试应用程序 1
This app tries to actually read from the device.
此应用程序尝试实际从设备读取。
===== Code =====
===== 代码 =====
public class ZeeTest extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
test();
} catch (IOException e) {
e.printStackTrace();
}
}
private BluetoothSocket sock;
private InputStream in;
public void test() throws IOException {
BluetoothDevice zee = BluetoothAdapter.getDefaultAdapter().
getRemoteDevice("00:1C:4D:02:A6:55");
sock = zee.createRfcommSocketToServiceRecord(
UUID.fromString("8e1f0cf7-508f-4875-b62c-fbb67fd34812"));
Log.d("ZeeTest", "++++ Connecting");
sock.connect();
Log.d("ZeeTest", "++++ Connected");
in = sock.getInputStream();
byte[] buffer = new byte[1];
int bytes = 0;
int x = 0;
Log.d("ZeeTest", "++++ Listening...");
while (x < 2) {
x++;
try {
bytes = in.read(buffer);
Log.d("ZeeTest", "++++ Read "+ bytes +" bytes");
} catch (IOException e) {
e.printStackTrace();
try { Thread.sleep(100); } catch (InterruptedException ie) {}
}
}
Log.d("ZeeTest", "++++ Done: test()");
}
@Override
public void onDestroy() {
try {
if (in != null) {
in.close();
}
if (sock != null) {
sock.close();
}
} catch (IOException e) {
e.printStackTrace();
}
super.onDestroy();
}
}
===== Log =====
===== 日志 =====
04-19 22:27:01.147: DEBUG/ZeeTest(8619): ++++ Connecting 04-19 22:27:04.085: INFO/usbd(1062): process_usb_uevent_message(): buffer = add@/devices/virtual/bluetooth/hci0/hci0:1 04-19 22:27:04.085: INFO/usbd(1062): main(): call select(...) 04-19 22:27:04.327: ERROR/BluetoothEventLoop.cpp(4029): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/4121/hci0/dev_00_1C_4D_02_A6_55 04-19 22:27:04.491: VERBOSE/BluetoothEventRedirector(7499): Received android.bleutooth.device.action.UUID 04-19 22:27:04.905: DEBUG/ZeeTest(8619): ++++ Connected 04-19 22:27:04.905: DEBUG/ZeeTest(8619): ++++ Listening... 04-19 22:27:05.538: WARN/System.err(8619): java.io.IOException: Software caused connection abort 04-19 22:27:05.600: WARN/System.err(8619): at android.bluetooth.BluetoothSocket.readNative(Native Method) ... 04-19 22:27:05.717: WARN/System.err(8619): java.io.IOException: Software caused connection abort 04-19 22:27:05.717: WARN/System.err(8619): at android.bluetooth.BluetoothSocket.readNative(Native Method) ... 04-19 22:27:05.819: DEBUG/ZeeTest(8619): ++++ Done: test() 04-19 22:27:07.155: VERBOSE/BluetoothEventRedirector(7499): Received android.bleutooth.device.action.UUID 04-19 22:27:09.077: INFO/usbd(1062): process_usb_uevent_message(): buffer = remove@/devices/virtual/bluetooth/hci0/hci0:1 04-19 22:27:09.085: INFO/usbd(1062): main(): call select(...) 04-19 22:27:09.139: ERROR/BluetoothEventLoop.cpp(4029): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/4121/hci0/dev_00_1C_4D_02_A6_55
Test application No. 2
测试申请第 2 号
This test connects and waits -- useful for displaying the auto-disconnect issue.
此测试连接并等待 - 用于显示自动断开连接问题。
===== Code =====
===== 代码 =====
public class ZeeTest extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
getApplicationContext().registerReceiver(receiver,
new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));
getApplicationContext().registerReceiver(receiver,
new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED));
try {
BluetoothDevice zee = BluetoothAdapter.getDefaultAdapter().
getRemoteDevice("00:1C:4D:02:A6:55");
sock = zee.createRfcommSocketToServiceRecord(
UUID.fromString("8e1f0cf7-508f-4875-b62c-fbb67fd34812"));
Log.d("ZeeTest", "++++ Connecting");
sock.connect();
Log.d("ZeeTest", "++++ Connected");
} catch (IOException e) {
e.printStackTrace();
}
}
private static final LogBroadcastReceiver receiver = new LogBroadcastReceiver();
public static class LogBroadcastReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Log.d("ZeeReceiver", intent.toString());
Bundle extras = intent.getExtras();
for (String k : extras.keySet()) {
Log.d("ZeeReceiver", " Extra: "+ extras.get(k).toString());
}
}
}
private BluetoothSocket sock;
@Override
public void onDestroy() {
getApplicationContext().unregisterReceiver(receiver);
if (sock != null) {
try {
sock.close();
} catch (IOException e) {
e.printStackTrace();
}
}
super.onDestroy();
}
}
===== Log =====
===== 日志 =====
04-19 22:06:34.944: DEBUG/ZeeTest(7986): ++++ Connecting
04-19 22:06:38.202: INFO/usbd(1062): process_usb_uevent_message(): buffer = add@/devices/virtual/bluetooth/hci0/hci0:1
04-19 22:06:38.202: INFO/usbd(1062): main(): call select(...)
04-19 22:06:38.217: ERROR/BluetoothEventLoop.cpp(4029): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/4121/hci0/dev_00_1C_4D_02_A6_55
04-19 22:06:38.428: VERBOSE/BluetoothEventRedirector(7499): Received android.bleutooth.device.action.UUID
04-19 22:06:38.968: DEBUG/ZeeTest(7986): ++++ Connected
04-19 22:06:39.061: DEBUG/ZeeReceiver(7986): Intent { act=android.bluetooth.device.action.ACL_CONNECTED (has extras) }
04-19 22:06:39.108: DEBUG/ZeeReceiver(7986): Extra: 00:1C:4D:02:A6:55
04-19 22:06:39.538: INFO/ActivityManager(4029): Displayed activity zee.test/.ZeeTest: 5178 ms (total 5178 ms)
04-19 22:06:41.014: VERBOSE/BluetoothEventRedirector(7499): Received android.bleutooth.device.action.UUID
04-19 22:06:43.038: INFO/usbd(1062): process_usb_uevent_message(): buffer = remove@/devices/virtual/bluetooth/hci0/hci0:1
04-19 22:06:43.038: INFO/usbd(1062): main(): call select(...)
04-19 22:06:43.069: ERROR/BluetoothEventLoop.cpp(4029): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/4121/hci0/dev_00_1C_4D_02_A6_55
04-19 22:06:43.124: DEBUG/ZeeReceiver(7986): Intent { act=android.bluetooth.device.action.ACL_DISCONNECTED (has extras) }
04-19 22:06:43.124: DEBUG/ZeeReceiver(7986): Extra: 00:1C:4D:02:A6:55
System logs
系统日志
===== Terminal log =====
======终端日志=====
$ sdptool browse
Inquiring ...
Browsing 00:1C:4D:02:A6:55 ...
$ sdptool records 00:1C:4D:02:A6:55
Service Name: Zeemote
Service RecHandle: 0x10015
Service Class ID List:
UUID 128: 8e1f0cf7-508f-4875-b62c-fbb67fd34812
Protocol Descriptor List:
"L2CAP" (0x0100)
"RFCOMM" (0x0003)
Channel: 1
Language Base Attr List:
code_ISO639: 0x656e
encoding: 0x6a
base_offset: 0x100
$ rfcomm connect /dev/tty10 00:1C:4D:02:A6:55
Connected /dev/rfcomm0 to 00:1C:4D:02:A6:55 on channel 1
Press CTRL-C for hangup
# rfcomm show /dev/tty10
rfcomm0: 00:1F:3A:E4:C8:40 -> 00:1C:4D:02:A6:55 channel 1 connected [reuse-dlc release-on-hup tty-attached]
# cat /dev/tty10
(nothing here)
# hcidump
HCI sniffer - Bluetooth packet analyzer ver 1.42
device: hci0 snap_len: 1028 filter: 0xffffffff
< HCI Command: Create Connection (0x01|0x0005) plen 13
> HCI Event: Command Status (0x0f) plen 4
> HCI Event: Connect Complete (0x03) plen 11
< HCI Command: Read Remote Supported Features (0x01|0x001b) plen 2
> HCI Event: Read Remote Supported Features (0x0b) plen 11
< ACL data: handle 11 flags 0x02 dlen 10
L2CAP(s): Info req: type 2
> HCI Event: Command Status (0x0f) plen 4
> HCI Event: Page Scan Repetition Mode Change (0x20) plen 7
> HCI Event: Max Slots Change (0x1b) plen 3
< HCI Command: Remote Name Request (0x01|0x0019) plen 10
> HCI Event: Command Status (0x0f) plen 4
> ACL data: handle 11 flags 0x02 dlen 16
L2CAP(s): Info rsp: type 2 result 0
Extended feature mask 0x0000
< ACL data: handle 11 flags 0x02 dlen 12
L2CAP(s): Connect req: psm 3 scid 0x0040
> HCI Event: Number of Completed Packets (0x13) plen 5
> ACL data: handle 11 flags 0x02 dlen 16
L2CAP(s): Connect rsp: dcid 0x04fb scid 0x0040 result 1 status 2
Connection pending - Authorization pending
> HCI Event: Remote Name Req Complete (0x07) plen 255
> ACL data: handle 11 flags 0x02 dlen 16
L2CAP(s): Connect rsp: dcid 0x04fb scid 0x0040 result 0 status 0
Connection successful
< ACL data: handle 11 flags 0x02 dlen 16
L2CAP(s): Config req: dcid 0x04fb flags 0x00 clen 4
MTU 1013
(events are properly received using bluez)
===== Part of adb bugreport =====
====== adb bugreport 的一部分 ======
--Known devices--
00:19:A1:2D:16:EA bonded (0) LG U830
00001105-0000-1000-8000-00805f9b34fb RFCOMM channel = 17
00:1C:4D:02:A6:55 bonded (0) Zeemote JS1
00:0B:2E:6E:6F:00 bonded (0) Motorola HS815
00001108-0000-1000-8000-00805f9b34fb RFCOMM channel = 1
0000111e-0000-1000-8000-00805f9b34fb RFCOMM channel = 2
00:1F:3A:E4:C8:40 bonded (0) BRCM BT4X
00001105-0000-1000-8000-00805f9b34fb RFCOMM channel = 9
00:18:42:EC:E2:99 bonded (0) N95
00001105-0000-1000-8000-00805f9b34fb RFCOMM channel = 9
===== Excerpt from boot log =====
====== 启动日志摘录 =====
04-18 21:55:10.382: VERBOSE/BluetoothEventRedirector(1985): Received android.bluetooth.adapter.action.STATE_CHANGED 04-18 21:55:10.421: DEBUG/BT HSHFP(1237): Loaded priority 00:19:A1:2D:16:EA = 100 04-18 21:55:10.428: DEBUG/BT HSHFP(1237): Loaded priority 00:1C:4D:02:A6:55 = 0 04-18 21:55:10.444: DEBUG/BT HSHFP(1237): Loaded priority 00:0B:2E:6E:6F:00 = 101 04-18 21:55:10.749: DEBUG/BT HSHFP(1237): Loaded priority 00:1F:3A:E4:C8:40 = 100 04-18 21:55:10.780: DEBUG/BT HSHFP(1237): Loaded priority 00:18:42:EC:E2:99 = 100
采纳答案by Denis L
Try to change your code for creating RfcommSocket:
尝试更改用于创建 RfcommSocket 的代码：
sock = zee.createRfcommSocketToServiceRecord(
UUID.fromString("8e1f0cf7-508f-4875-b62c-fbb67fd34812"));
for this code:
对于此代码：
Method m = zee.getClass().getMethod("createRfcommSocket", new Class[] { int.class });
sock = (BluetoothSocket) m.invoke(device, 1);
Also try to change argument value in range 1-3 in this m.invoke(device, 1); When connection will be Connected, but aborted when you try reading, call in some loop your method test() again. As simple:
还尝试在此 m.invoke(device, 1); 中更改 1-3 范围内的参数值；当连接已连接但在您尝试阅读时中止时，请再次在某个循环中调用您的方法 test()。很简单：
for(int i=0;i<3;i++){ if(!testDone) test(); }
回答by fishjd
I merged code I had written and code from [android-beginners] Re: Serial over Bluetooth by XCaffeinated]1and the above post.
我合并了我编写的代码和来自 [android-beginners] Re: Serial over Bluetooth by XCaffeinated] 1和上述帖子的代码。
To create the simplest bluetooth program possible.
创建最简单的蓝牙程序。
The main addition for this code is add better handling on the exceptions thrown by connect().
此代码的主要添加是对connect().
Search for '@todo' to customize for your needs.
搜索“@todo”以根据您的需要进行自定义。
I hope this saves you some time!
我希望这可以为您节省一些时间！
package com.xxx; // @todo Change to your package.
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.os.Bundle;
import android.util.Log;
/**
* This is the simplest bluetooth program. It sends one message to one bluetooth
* device. The message and the bluetooth hardware id for the device are hard
* coded. <br>
* <br>
* It does <b>not</b> receive any data. It does not do any thread processing. <br>
* <br>
*
* This application will be useful to communicate with a bluetooth hardware
* device such as a bar code reader, Lego Mindstorm, a PC with a com port
* application, a PC with a terminal program with 'listening' to a com port, a
* second android device with a terminal program such as <a href=
* "http://www.tec-it.com/en/software/data-acquisition/getblue/android-smartphone/Default.aspx"
* >GetBlue</a>. It is not a full android bluetooth application but more a proof
* of concept that the bluetooth works.
*
* <br>
* <br>
*
* This code should cut and paste into the <a
* href="http://developer.android.com/resources/tutorials/hello-world.html>
* 'HelloAndroid' example</a>. It does not use any screen io.
*
* Add to your Android Manifest.xml file: <uses-permission
* android:name="android.permission.BLUETOOTH" /> <uses-permission
* android:name="android.permission.BLUETOOTH_ADMIN" />
*
* For a proper bluetooth example with threading and receiving data see: <a
* href=
* "http://developer.android.com/resources/samples/BluetoothChat/index.html"
* >http://developer.android.com/resources/samples/BluetoothChat/index.html</a>
*
* @see <a
* href="http://developer.android.com/guide/topics/wireless/bluetooth.html">
* http://developer.android.com/guide/topics/wireless/bluetooth.html</a>
*
*/
public class BlueToothTesterActivity extends Activity {
/** The BluetoothAdapter is the gateway to all bluetooth functions **/
protected BluetoothAdapter bluetoothAdapter = null;
/** We will write our message to the socket **/
protected BluetoothSocket socket = null;
/** The Bluetooth is an external device, which will receive our message **/
BluetoothDevice blueToothDevice = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Grab the BlueToothAdapter. The first line of most bluetooth programs.
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// if the BluetoothAdapter.getDefaultAdapter(); returns null then the
// device does not have bluetooth hardware. Currently the emulator
// does not support bluetooth so this will this condition will be true.
// i.e. This code only runs on a hardware device an not on the emulator.
if (bluetoothAdapter == null) {
Log.e(this.toString(), "Bluetooth Not Available.");
return;
}
// This will find the remote device given the bluetooth hardware
// address.
// @todo: Change the address to the your device address
blueToothDevice = bluetoothAdapter.getRemoteDevice("00:00:00:00:00:00");
for (Integer port = 1; port <= 3; port++) {
simpleComm(Integer.valueOf(port));
}
}
protected void simpleComm(Integer port) {
// byte [] inputBytes = null;
// The documents tell us to cancel the discovery process.
bluetoothAdapter.cancelDiscovery();
Log.d(this.toString(), "Port = " + port);
try {
// This is a hack to access "createRfcommSocket which is does not
// have public access in the current api.
// Note: BlueToothDevice.createRfcommSocketToServiceRecord (UUID
// uuid) does not work in this type of application. .
Method m = blueToothDevice.getClass().getMethod(
"createRfcommSocket", new Class[] { int.class });
socket = (BluetoothSocket) m.invoke(blueToothDevice, port);
// debug check to ensure socket was set.
assert (socket != null) : "Socket is Null";
// attempt to connect to device
socket.connect();
try {
Log.d(this.toString(),
"************ CONNECTION SUCCEES! *************");
// Grab the outputStream. This stream will send bytes to the
// external/second device. i.e it will sent it out.
// Note: this is a Java.io.OutputStream which is used in several
// types of Java programs such as file io, so you may be
// familiar with it.
OutputStream outputStream = socket.getOutputStream();
// Create the String to send to the second device.
// Most devices require a '\r' or '\n' or both at the end of the
// string.
// @todo set your message
String message = "Data from Android and tester program!\r";
// Convert the message to bytes and blast it through the
// bluetooth
// to the second device. You may want to use:
// public byte[] getBytes (Charset charset) for proper String to
// byte conversion.
outputStream.write(message.getBytes());
} finally {
// close the socket and we are done.
socket.close();
}
// IOExcecption is thrown if connect fails.
} catch (IOException ex) {
Log.e(this.toString(), "IOException " + ex.getMessage());
// NoSuchMethodException IllegalAccessException
// InvocationTargetException
// are reflection exceptions.
} catch (NoSuchMethodException ex) {
Log.e(this.toString(), "NoSuchMethodException " + ex.getMessage());
} catch (IllegalAccessException ex) {
Log.e(this.toString(), "IllegalAccessException " + ex.getMessage());
} catch (InvocationTargetException ex) {
Log.e(this.toString(),
"InvocationTargetException " + ex.getMessage());
}
}
}
回答by Brad Hein
If I understand correctly, your app is unable to see any data from the device whatsoever?
如果我理解正确，您的应用程序无法查看设备中的任何数据？
One small thing: try your UUID without hiphens. In my RFCOMM apps I actually define the UUID as a long integer constant.
一件小事：在没有 hiphens 的情况下尝试您的 UUID。在我的 RFCOMM 应用程序中，我实际上将 UUID 定义为一个长整数常量。
Also, the way your test() method is written leads me to believe the test() is making the connection, defining a thread, telling it to start and immediately returning. In other words, your thread is referencing a variable from outside of the thread which is part of the test() method but when test() dies, so does its variables.
此外，您的 test() 方法的编写方式让我相信 test() 正在建立连接，定义一个线程，告诉它开始并立即返回。换句话说，您的线程正在从线程外部引用一个变量，该变量是 test() 方法的一部分，但是当 test() 终止时，它的变量也会终止。
In short, try your testing outside of a thread and get it working there first. One easy way to do this would be to use Thread.run() instead of thread.start(). .run() runs it in the foreground (and thus blocks test() so it doesn't return before the thread finished).
简而言之，在线程之外尝试您的测试，然后先让它在那里工作。一种简单的方法是使用 Thread.run() 而不是 thread.start()。.run() 在前台运行它（并因此阻塞 test() 所以它不会在线程完成之前返回）。
For a longer term solution you may wish to define your Bluetooth variables as gloibal/member variables so they don't go out of scope and are always available to your thread.
对于长期解决方案，您可能希望将蓝牙变量定义为全局/成员变量，这样它们就不会超出范围并且始终可供您的线程使用。
回答by android_junkie
Try the well known UUID:00001101-0000-1000-8000-00805F9B34FB
试试众所周知的 UUID：00001101-0000-1000-8000-00805F9B34FB
回答by vanomart
Code above not worked on Samsung Galaxy tab 2 with 4.0.4. BTSocket.connect always fired bluetooth pairing dialog and then failed, even if correct pin was typed. Changing from "createRfcommSocket" to "createInsecureRfcommSocket" solved the problem. Hope this will help, I struggled with this issue for more than 3 hours.
上面的代码不适用于 4.0.4 的三星 Galaxy tab 2。BTSocket.connect 总是触发蓝牙配对对话框然后失败，即使输入了正确的 pin。从“createRfcommSocket”更改为“createInsecureRfcommSocket”解决了问题。希望这会有所帮助，我在这个问题上挣扎了 3 个多小时。
