Android 應用程序使用 arduino 強制關閉

Question

我正在開發一個帶有 eclipse 和 arduino 的應用程序，它連接到一個藍牙模塊。 然后我可以控制板上的 LED。 但是，我的代碼沒有顯示任何錯誤，但是每次我按下按鈕時應用程序強制都會關閉。 這是我的代碼：

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.widget.TextView;
import android.widget.Button;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;

public class BluetoothTest extends Activity
{
TextView labelConnect;
BluetoothAdapter mBluetoothAdapter;
BluetoothSocket mmSocket;
BluetoothDevice mmDevice;
OutputStream mmOutputStream;


@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Button openButton = (Button)findViewById(R.id.open);
    Button closeButton = (Button)findViewById(R.id.close);

    Button onButton  = (Button)findViewById(R.id.onButton);
    Button offButton = (Button)findViewById(R.id.offButton);

    Button redButton  = (Button)findViewById(R.id.redButton);
    Button greenButton = (Button)findViewById(R.id.greenButton);
    Button blueButton = (Button)findViewById(R.id.blueButton);

    labelConnect = (TextView)findViewById(R.id.mylabel);

    //Open Bluetooth
    openButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                findBT();
                openBT();
            }
            catch (IOException ex) { }
        }
    });

    //Close Bluetooth
    closeButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                closeBT();
            }
            catch (IOException ex) { }
        }
    });

  //Red Button
    redButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                redButton();
            }
            catch (IOException ex) { }
        }
    });

    //Green Button
    greenButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                greenButton();
            }
            catch (IOException ex) { }
        }
    });

    //Blue Button
    blueButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                blueButton();
            }
            catch (IOException ex) { }
        }
    });

    //On Button    - set strip to white
    onButton.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            try {
                onButton();
            } catch (Exception e) {
                // TODO: handle exception
            }

        }
    });

  //Off Button    - set strip to all OFF
    offButton.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            try {
                offButton();
            } catch (Exception e) {
                // TODO: handle exception
            }

        }
    });


}  // end onCreate 


void findBT()
{
    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if(mBluetoothAdapter == null)
    {
        labelConnect.setText("No bluetooth adapter available");
    }

    if(!mBluetoothAdapter.isEnabled())
    {
        Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBluetooth, 0);
    }

    Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
    if(pairedDevices.size() > 0)
    {
        for(BluetoothDevice device : pairedDevices)
        {
            if(device.getName().equals("BTNode0"))    // Change to match RN42 - node name
            {
                mmDevice = device;
                Log.i("ArduinoBT", "findBT found device named " + mmDevice.getName());
                Log.i("ArduinoBT", "device address is " + mmDevice.getAddress());
                break;
            }
        }
    }
    labelConnect.setText("Bluetooth Device Found");
}

void openBT() throws IOException
{
    UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"); //Standard SerialPortService ID
    mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);        
    mmSocket.connect();
    mmOutputStream = mmSocket.getOutputStream();

    labelConnect.setText("BT  << " + mmDevice.getName()  + " >> is now open ");
}

void closeBT() throws IOException
{
    mmOutputStream.close();
    mmSocket.close();
    labelConnect.setText("Bluetooth Closed");
}


  void offButton() throws IOException
{
    mmOutputStream.write("0".getBytes());
}


void redButton() throws IOException
{
    mmOutputStream.write("1".getBytes());
}

void greenButton() throws IOException
{
    mmOutputStream.write("2".getBytes());
}

void blueButton() throws IOException
{
    mmOutputStream.write("3".getBytes());
}

void onButton() throws IOException
{
    mmOutputStream.write("4".getBytes());
}



}

這是我點擊連接按鈕時發生的事情的日志

04-25 12:15:10.771: W/asset(22604): Copying FileAsset 0x74c0a9d8 (zip:/data/app/Android.Arduino.Bluetooth-2.apk:/resources.arsc) to buffer size 1912 to make it aligned.
04-25 12:15:10.821: D/RenderPolicy(22604): ViewRootImpl.enableHardwareAcceleration -> enableRenderPolicy
04-25 12:15:10.881: I/Adreno-EGL(22604): <qeglDrvAPI_eglInitialize:316>: EGL 1.4 QUALCOMM build:  (CL4169980)
04-25 12:15:10.881: I/Adreno-EGL(22604): OpenGL ES Shader Compiler Version: 17.01.10.SPL
04-25 12:15:10.881: I/Adreno-EGL(22604): Build Date: 02/04/14 Tue
04-25 12:15:10.881: I/Adreno-EGL(22604): Local Branch: 
04-25 12:15:10.881: I/Adreno-EGL(22604): Remote Branch: 
04-25 12:15:10.881: I/Adreno-EGL(22604): Local Patches: 
04-25 12:15:10.881: I/Adreno-EGL(22604): Reconstruct Branch: 
04-25 12:15:12.363: W/dalvikvm(22604): threadid=1: thread exiting with uncaught exception (group=0x41625e18)
04-25 12:15:12.373: E/AndroidRuntime(22604): FATAL EXCEPTION: main
04-25 12:15:12.373: E/AndroidRuntime(22604): Process: Android.Arduino.Bluetooth, PID: 22604
04-25 12:15:12.373: E/AndroidRuntime(22604): java.lang.NullPointerException
04-25 12:15:12.373: E/AndroidRuntime(22604):    at Android.Arduino.Bluetooth.BluetoothTest.openBT(BluetoothTest.java:185)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at Android.Arduino.Bluetooth.BluetoothTest$1.onClick(BluetoothTest.java:53)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at android.view.View.performClick(View.java:4480)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at android.view.View$PerformClick.run(View.java:18673)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at android.os.Handler.handleCallback(Handler.java:733)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at android.os.Handler.dispatchMessage(Handler.java:95)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at android.os.Looper.loop(Looper.java:157)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at android.app.ActivityThread.main(ActivityThread.java:5872)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at java.lang.reflect.Method.invokeNative(Native Method)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at java.lang.reflect.Method.invoke(Method.java:515)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1069)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:885)
04-25 12:15:12.373: E/AndroidRuntime(22604):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

由於他們已經在評論中表示， mmDevice您試圖在使用openBT方法是無效的，因為沒有設備是在發現findBT方法和變量未初始化。 您需要修復您的代碼，以便在未找到設備的情況下不要嘗試打開連接。

解決此問題后，代碼中的另一個主要問題是您嘗試在主線程中打開的 SocketConnection。 按鈕處理程序和 GUI 事件在主線程中執行，因此您的openBT應移至單獨的線程（或更好的服務）。