我在 Arduino 的模块 HC-05 和我在 AndroidStudio 上的 android 应用程序之间的连接有问题。当我尝试连接时，日志显示在创建套接字后，它没有建立连接。为什么？这是我建立连接的代码部分：
if(nome_device.equals("BT05") || nome_device.equals("BT06")){
BluetoothDevice dev = mBlueadapter.getRemoteDevice(MAC_address);
ParcelUuid list[] = dev.getUuids();
System.out.println("ciao");
System.out.println(dev);
BluetoothSocket btSocket = null;
int count = 0;
do {
try {
btSocket = dev.createRfcommSocketToServiceRecord(uuid); //creo un socket per comunicare
// System.out.println(dev);
// System.out.println(btSocket);
btSocket.connect(); //avvio la connessione
System.out.println(btSocket.isConnected());
} catch (IOException e) {
e.printStackTrace();
}
count++;
} while(!btSocket.isConnected() && count < 3);
try {
OutputStream outputStream = btSocket.getOutputStream();
outputStream.write(48);
} catch (IOException e) {
e.printStackTrace();
}
try {
InputStream inputStream = btSocket.getInputStream();
inputStream.skip(inputStream.available()); //pulisce il buffer
for(int i=0; i<26; i++){
byte b = (byte) inputStream.read();
System.out.println((char) b);
}
} catch (IOException e) {
e.printStackTrace();
}
try {
btSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
else
Toast.makeText(this, "The selected device is not compatible with this app! ", Toast.LENGTH_SHORT).show();
这是我单击模块名称后的日志：
2021-03-15 21:22:43.978 8585-8585/com.example.skatex W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)
2021-03-15 21:22:43.983 8585-8585/com.example.skatex D/BluetoothUtils: isSocketAllowedBySecurityPolicy start : device null
2021-03-15 21:22:43.984 8585-8585/com.example.skatex W/System.err: java.io.IOException: bt socket closed, read return: -1
2021-03-15 21:22:43.985 8585-8585/com.example.skatex W/System.err: at android.bluetooth.BluetoothSocket.read(BluetoothSocket.java:721)
2021-03-15 21:22:43.985 8585-8585/com.example.skatex W/System.err: at android.bluetooth.BluetoothInputStream.read(BluetoothInputStream.java:59)
2021-03-15 21:22:43.986 8585-8585/com.example.skatex W/System.err: at com.example.skatex.Bluetooth.connection(Bluetooth.java:200)
2021-03-15 21:22:43.986 8585-8585/com.example.skatex W/System.err: at com.example.skatex.Bluetooth.access$200(Bluetooth.java:32)
2021-03-15 21:22:43.986 8585-8585/com.example.skatex W/System.err: at com.example.skatex.Bluetooth$2.onItemClick(Bluetooth.java:93)
2021-03-15 21:22:43.987 8585-8585/com.example.skatex W/System.err: at android.widget.AdapterView.performItemClick(AdapterView.java:374)
2021-03-15 21:22:43.987 8585-8585/com.example.skatex W/System.err: at android.widget.AbsListView.performItemClick(AbsListView.java:1736)
2021-03-15 21:22:43.987 8585-8585/com.example.skatex W/System.err: at android.widget.AbsListView$PerformClick.run(AbsListView.java:4207)
2021-03-15 21:22:43.988 8585-8585/com.example.skatex W/System.err: at android.widget.AbsListView$7.run(AbsListView.java:6692)
2021-03-15 21:22:43.988 8585-8585/com.example.skatex W/System.err: at android.os.Handler.handleCallback(Handler.java:883)
2021-03-15 21:22:43.989 8585-8585/com.example.skatex W/System.err: at android.os.Handler.dispatchMessage(Handler.java:100)
2021-03-15 21:22:43.989 8585-8585/com.example.skatex W/System.err: at android.os.Looper.loop(Looper.java:237)
2021-03-15 21:22:43.989 8585-8585/com.example.skatex W/System.err: at android.app.ActivityThread.main(ActivityThread.java:8107)
2021-03-15 21:22:43.990 8585-8585/com.example.skatex W/System.err: at java.lang.reflect.Method.invoke(Native Method)
2021-03-15 21:22:43.990 8585-8585/com.example.skatex W/System.err: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
2021-03-15 21:22:43.990 8585-8585/com.example.skatex W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)
2021-03-15 21:22:43.992 8585-8585/com.example.skatex D/BluetoothSocket: close() this: android.bluetooth.BluetoothSocket@3a48555, channel: -1, mSocketIS: android.net.LocalSocketImpl$SocketInputStream@26adb6a, mSocketOS: android.net.LocalSocketImpl$SocketOutputStream@455e85bmSocket: android.net.LocalSocket@6c1d8f8 impl:android.net.LocalSocketImpl@87521d1 fd:java.io.FileDescriptor@2d34436, mSocketState: INIT
2021-03-15 21:22:43.994 8585-8585/com.example.skatex I/Choreographer: Skipped 1163 frames! The application may be doing too much work on its main thread.
如果有人可以帮助我，我将不胜感激。