这是我用来通过蓝牙发送数据的代码，如果我点击按钮就可以正常工作，但如果我直接调用函数sendData（String ...）而不点击按钮，我就无法使用它。
我正在尝试更改单击按钮以使用语音识别。
如果我使用
，效果很好public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "In onCreate()");
setContentView(R.layout.main);
btnOn = (Button) findViewById(R.id.btnOn);
btnOff = (Button) findViewById(R.id.btnOff);
btAdapter = BluetoothAdapter.getDefaultAdapter();
checkBTState();
btnOn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
sendData("a");
Toast msg = Toast.makeText(getBaseContext(),
"You have clicked On", Toast.LENGTH_SHORT);
msg.show();
}
});
btnOff.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
sendData("b");
Toast msg = Toast.makeText(getBaseContext(),
"You have clicked Off", Toast.LENGTH_SHORT);
msg.show();
}
});}
但如果我将sendData移到外面，它就不起作用
btnOff.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
}
});
sendData("b");
这是完整的代码
import java.io.IOException;
import java.io.OutputStream;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
import com.example.ledonoff.R;
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.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.speech.RecognizerIntent;
import java.util.ArrayList;
import java.util.Locale;
import android.content.ActivityNotFoundException;
public class LEDOnOff extends Activity {
private static final String TAG = "LEDOnOff";
Button btnOn, btnOff, btnSpeak;
public String cmd = "none";
private final int SPEECH_RECOGNITION_CODE = 1;
private static final int REQUEST_ENABLE_BT = 1;
private BluetoothAdapter btAdapter = null;
private BluetoothSocket btSocket = null;
private OutputStream outStream = null;
private TextView textout;
// Well known SPP UUID
private static final UUID MY_UUID =
UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// Insert your bluetooth devices MAC address
private static String address = "98:D3:32:10:91:1F";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "In onCreate()");
setContentView(R.layout.main);
btnOn = (Button) findViewById(R.id.btnOn);
btnOff = (Button) findViewById(R.id.btnOff);
btnSpeak = (Button) findViewById(R.id.btnSpeak);
textout = (TextView) findViewById(R.id.textout);
btAdapter = BluetoothAdapter.getDefaultAdapter();
checkBTState();
btnOn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
sendData("a");
Toast msg = Toast.makeText(getBaseContext(),
"You have clicked On", Toast.LENGTH_SHORT);
msg.show();
}
});
btnOff.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
sendData("b");
Toast msg = Toast.makeText(getBaseContext(),
"You have clicked Off", Toast.LENGTH_SHORT);
msg.show();
}
});
btnSpeak.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
startSpeechToText();
}
});
}
/**
* Start speech to text intent. This opens up Google Speech Recognition API dialog box to listen the speech input.
* */
private void startSpeechToText() {
Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE, Locale.getDefault());
intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,
RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
intent.putExtra(RecognizerIntent.EXTRA_PROMPT,
"Speak something...");
try {
startActivityForResult(intent, SPEECH_RECOGNITION_CODE);
} catch (ActivityNotFoundException a) {
Toast.makeText(getApplicationContext(),
"Sorry! Speech recognition is not supported in this device.",
Toast.LENGTH_SHORT).show();
}
}
/**
* Callback for speech recognition activity
* */
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case SPEECH_RECOGNITION_CODE: {
if (resultCode == RESULT_OK && null != data) {
ArrayList<String> result = data
.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
String text = result.get(0);
textout.setText(text);
}
break;
}
}
}
public String VoiceFilter(String str_voice_input){
if(str_voice_input.contains("on") ){sendData("a"); //TEST SENDING DATA
return "a" ;
}
if(str_voice_input.contains("off") ){sendData("b"); //TEST SENDING DATA
return "b" ;
}
return "c";
}
@Override
public void onResume() {
super.onResume();
Log.d(TAG, "...In onResume - Attempting client connect...");
// 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 = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
errorExit("Fatal Error", "In onResume() and socket create failed: " + e.getMessage() + ".");
}
// Discovery is resource intensive. Make sure it isn't going on
// when you attempt to connect and pass your message.
btAdapter.cancelDiscovery();
// Establish the connection. This will block until it connects.
Log.d(TAG, "...Connecting to Remote...");
try {
btSocket.connect();
Log.d(TAG, "...Connection established and data link opened...");
} 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.
Log.d(TAG, "...Creating Socket...");
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();
Log.d(TAG, "...In 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 checkBTState() {
// Check for Bluetooth support and then check to make sure it is turned on
// Emulator doesn't support Bluetooth and will return null
if(btAdapter==null) {
errorExit("Fatal Error", "Bluetooth Not supported. Aborting.");
} else {
if (btAdapter.isEnabled()) {
Log.d(TAG, "...Bluetooth is enabled...");
} else {
//Prompt user to turn on Bluetooth
Intent enableBtIntent = new Intent(btAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
}
private void errorExit(String title, String message){
Toast msg = Toast.makeText(getBaseContext(),
title + " - " + message, Toast.LENGTH_SHORT);
msg.show();
finish();
}
private void sendData(String message) {
byte[] msgBuffer = message.getBytes();
Log.d(TAG, "...Sending data: " + message + "...");
try {
outStream.write(msgBuffer);
} catch (IOException e) {
String msg = "In onResume() and an exception occurred during write: " + e.getMessage();
if (address.equals("00:00:00:00:00:00"))
msg = msg + ".\n\nUpdate your server address from 00:00:00:00:00:00 to the correct address on line 37 in the java code";
msg = msg + ".\n\nCheck that the SPP UUID: " + MY_UUID.toString() + " exists on server.\n\n";
errorExit("Fatal Error", msg);
}
}
}
答案 0 :(得分：1)
您是否尝试在sendData("b")方法中执行OnCreate()？因为如果是这样，它就不会起作用，因为尚未与其他设备建立连接。建立连接后，尝试在onResume()中运行它。建立连接后立即开始传输可能会导致初始数据丢失，因此创建一个线程并等待一秒钟并开始通信。