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正如您所看到的，我制作了一个应用程序，可将数据从Android设备发送到蓝牙模块。除了一件小事：除了一件小事外，一切都可以完美运行：每当我打开应用程序时，我都应该已经通过手机设置打开蓝牙，否则应用程序会崩溃，打开蓝牙后必须重新打开它，以便它能够正常运行。通过在Android和Arduino之间传输数据实现蓝牙问题
我设计了一个蓝牙点击监听器按钮，但它仍然崩溃，而我通过按钮启用它。
你能帮我找到我的代码中的错误吗？
public class MainActivity extends AppCompatActivity {
private static final String TAG = "bluetooth1";
Button btnsend ;
EditText edttext ;
Button btnOnOff;
private BluetoothAdapter btAdapter = null;
private BluetoothSocket btSocket = null;
private OutputStream outStream = null;
// SPP UUID service
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// MAC-address of Bluetooth module (you must edit this line)
private static String address = "20:16:06:28:17:83";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnsend = (Button) findViewById(R.id.btnsend);
edttext = (EditText) findViewById(R.id.edttxt);
btnOnOff = (Button) findViewById(R.id.btnOnOff);
btAdapter = BluetoothAdapter.getDefaultAdapter();
btnOnOff.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
if (btAdapter.isEnabled()) {
btAdapter.disable();
Toast.makeText(getApplicationContext(), " Disabling Bluetooth", Toast.LENGTH_SHORT).show();
} else {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent,1);
Toast.makeText(getApplicationContext(), " Enabling Bluetooth", Toast.LENGTH_SHORT).show();
}
}
});
edttext.setInputType(InputType.TYPE_CLASS_NUMBER | InputType.TYPE_NUMBER_VARIATION_PASSWORD);
edttext.setTransformationMethod(new NumericKeyBoardTransformationMethod());
btnsend.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
String dataTransmit = edttext.getText().toString();
if (dataTransmit != null) {
sendData(dataTransmit);
} else {
Toast.makeText(getApplicationContext(), "Please type something first", Toast.LENGTH_SHORT).show();
}
}
});
}
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
if(Build.VERSION.SDK_INT >= 10) {
try {
final Method m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", new Class[] { UUID.class });
return (BluetoothSocket) m.invoke(device, MY_UUID);
} catch (Exception e) {
Toast.makeText(getBaseContext(), "Could not Insecure", Toast.LENGTH_SHORT).show();
}
}
return device.createRfcommSocketToServiceRecord(MY_UUID);
}
@Override
public void onResume() {
super.onResume();
// Set up a pointer to the remote node using it's address.
BluetoothDevice device = btAdapter.getRemoteDevice(address);
// Two things are needed to make a connection:
// A MAC address, which we got above.
// A Service ID or UUID. In this case we are using the
// UUID for SPP.
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e1) {
errorExit("Fatal Error", "In onResume() and socket create failed: " + e1.getMessage() + ".");
}
btAdapter.cancelDiscovery();
// Establish the connection. This will block until it connects.
Toast.makeText(getBaseContext(), "Connecting", Toast.LENGTH_SHORT).show();
try {
btSocket.connect();
Toast.makeText(getBaseContext(), "Connecting Ok", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
errorExit("Fatal Error", "In onResume() and unable to close socket during connection failure" + e2.getMessage() + ".");
}
}
// Create a data stream so we can talk to server.
try {
outStream = btSocket.getOutputStream();
} catch (IOException e) {
errorExit("Fatal Error", "In onResume() and output stream creation failed:" + e.getMessage() + ".");
}
}
@Override
public void onPause() {
super.onPause();
if (outStream != null) {
try {
outStream.flush();
} catch (IOException e) {
errorExit("Fatal Error", "In onPause() and failed to flush output stream: " + e.getMessage() + ".");
}
}
try {
btSocket.close();
} catch (IOException e2) {
errorExit("Fatal Error", "In onPause() and failed to close socket." + e2.getMessage() + ".");
}
}
private void errorExit(String title, String message) {
Toast.makeText(getBaseContext(), title + " - " + message, Toast.LENGTH_LONG).show();
finish();
}
private void sendData(String message) {
byte[] msgBuffer = message.getBytes();
try {
outStream.write(msgBuffer);
} catch (IOException e) {
String msg = "In onResume() and an exception occurred during write: " + e.getMessage();
if (address.equals("20:16:06:28:17:83"))
msg = msg + ".\n\nUpdate your server address from 20:16:06:28:17:83 to the correct address on line 35 in the java code";
msg = msg + ".\n\nCheck that the SPP UUID: " + MY_UUID.toString() + " exists on server.\n\n";
errorExit("Fatal Error", msg);
}
}
}