android - 开始 Activity 时崩溃

Question

我正在编写一个 Android 应用程序。该应用程序从主屏幕开始，然后单击按钮进行 Activity 。我的代码没有任何错误并且构建良好。但是启动应用程序并单击按钮会导致崩溃。

我的 list .XML

    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.androidbtcontrol">
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".bluetoothconnect">
            <intent-filter>
                <action android:name="com.example.androidbtcontrol.bluetoothconnect" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

    </application>

</manifest>

MainActivity.java

    public void OnclickButtonListener(){
    button_1 = (Button)findViewById(R.id.button);
    button_1.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent intent = new Intent("com.example.androidbtcontrol.bluetoothconnect");
                    startActivity(intent);
                }
            }
    );
         }
            }

蓝牙连接.java

    public class bluetoothconnect extends AppCompatActivity {

    protected void onCreate3(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_bluetoothconnect);
    }
    private static final int REQUEST_ENABLE_BT = 1;

    BluetoothAdapter bluetoothAdapter;

    ArrayList<BluetoothDevice> pairedDeviceArrayList;

    TextView textInfo, textStatus;
    ListView listViewPairedDevice;
    RelativeLayout inputPane;

    SeekBar barAnalogOut;

    ArrayAdapter<BluetoothDevice> pairedDeviceAdapter;
    private UUID myUUID;
    private final String UUID_STRING_WELL_KNOWN_SPP =
            "00001101-0000-1000-8000-00805F9B34FB";

    ThreadConnectBTdevice myThreadConnectBTdevice;
    ThreadConnected myThreadConnected;


    protected void onCreate2(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textInfo = (TextView)findViewById(R.id.info);
        textStatus = (TextView)findViewById(R.id.status);
        listViewPairedDevice = (ListView)findViewById(R.id.pairedlist);

        inputPane = (RelativeLayout) findViewById(R.id.inputpane);

        if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)){
            Toast.makeText(this,
                    "FEATURE_BLUETOOTH NOT support",
                    Toast.LENGTH_LONG).show();
            finish();
            return;
        }

        //using the well-known SPP UUID
        myUUID = UUID.fromString(UUID_STRING_WELL_KNOWN_SPP);

        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (bluetoothAdapter == null) {
            Toast.makeText(this,
                    "Bluetooth is not supported on this hardware platform",
                    Toast.LENGTH_LONG).show();
            finish();
            return;
        }

        String stInfo = bluetoothAdapter.getName() + "\n" +
                bluetoothAdapter.getAddress();
        textInfo.setText(stInfo);

        barAnalogOut = (SeekBar)findViewById(R.id.analogOut);
        barAnalogOut.setOnSeekBarChangeListener(OnAnalogOutChangeListener);

    }

    SeekBar.OnSeekBarChangeListener OnAnalogOutChangeListener =
            new SeekBar.OnSeekBarChangeListener(){
                @Override
                public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                    //will generate too much data sent!
                    //SendAnalogOut(progress);
                }

                @Override
                public void onStartTrackingTouch(SeekBar seekBar) {

                }

                @Override
                public void onStopTrackingTouch(SeekBar seekBar) {
                    SendAnalogOut(seekBar.getProgress());
                }
            };

    private final byte SYNC_BYTE = (byte) 0xAA;
    private final byte LENGTH_ANALOG = (byte) 3;
    private final byte CMD_ANALOG = (byte) 1;

    private void SendAnalogOut(int val){
        byte[] bytesToSend = {SYNC_BYTE, LENGTH_ANALOG, CMD_ANALOG, (byte) val};
        myThreadConnected.write(bytesToSend);
    }

    @Override
    protected void onStart() {
        super.onStart();

        //Turn ON BlueTooth if it is OFF
        if (!bluetoothAdapter.isEnabled()) {
            Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
        }

        setup();
    }

    private void setup() {
        Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
        if (pairedDevices.size() > 0) {
            pairedDeviceArrayList = new ArrayList<BluetoothDevice>();

            for (BluetoothDevice device : pairedDevices) {
                pairedDeviceArrayList.add(device);
            }

            pairedDeviceAdapter = new ArrayAdapter<BluetoothDevice>(this,
                    android.R.layout.simple_list_item_1, pairedDeviceArrayList);
            listViewPairedDevice.setAdapter(pairedDeviceAdapter);

            listViewPairedDevice.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                                        int position, long id) {
                    BluetoothDevice device =
                            (BluetoothDevice) parent.getItemAtPosition(position);
                    Toast.makeText(bluetoothconnect.this,
                            "Name: " + device.getName() + "\n"
                                    + "Address: " + device.getAddress() + "\n"
                                    + "BondState: " + device.getBondState() + "\n"
                                    + "BluetoothClass: " + device.getBluetoothClass() + "\n"
                                    + "Class: " + device.getClass(),
                            Toast.LENGTH_LONG).show();

                    textStatus.setText("start ThreadConnectBTdevice");
                    myThreadConnectBTdevice = new ThreadConnectBTdevice(device);
                    myThreadConnectBTdevice.start();
                }
            });
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        if(myThreadConnectBTdevice!=null){
            myThreadConnectBTdevice.cancel();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(requestCode==REQUEST_ENABLE_BT){
            if(resultCode == Activity.RESULT_OK){
                setup();
            }else{
                Toast.makeText(this,
                        "BlueTooth NOT enabled",
                        Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    }

    //Called in ThreadConnectBTdevice once connect successed
    //to start ThreadConnected
    private void startThreadConnected(BluetoothSocket socket){

        myThreadConnected = new ThreadConnected(socket);
        myThreadConnected.start();
    }

    /*
    ThreadConnectBTdevice:
    Background Thread to handle BlueTooth connecting
    */
    private class ThreadConnectBTdevice extends Thread {

        private BluetoothSocket bluetoothSocket = null;
        private final BluetoothDevice bluetoothDevice;


        private ThreadConnectBTdevice(BluetoothDevice device) {
            bluetoothDevice = device;

            try {
                bluetoothSocket = device.createRfcommSocketToServiceRecord(myUUID);
                textStatus.setText("bluetoothSocket: \n" + bluetoothSocket);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        @Override
        public void run() {
            ToggleButton toggle = (ToggleButton) findViewById(R.id.toggleButton);
            toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if (isChecked) {
                        SendAnalogOut( 0);
                        // The toggle is enabled
                    } else {
                        SendAnalogOut( 255);
                        // The toggle is disabled
                    }
                }
            });
            boolean success = false;
            try {
                bluetoothSocket.connect();
                success = true;
            } catch (IOException e) {
                e.printStackTrace();

                final String eMessage = e.getMessage();
                runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        textStatus.setText("Something wrong BluetoothSocket.connect(): \n" + eMessage);
                    }
                });

                try {
                    bluetoothSocket.close();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            }

            if(success){
                //connect successful
                final String msgconnected = "Connect Successful:\n"
                        + "BluetoothSocket: " + bluetoothSocket + "\n"
                        + "BluetoothDevice: " + bluetoothDevice;

                runOnUiThread(new Runnable(){

                    @Override
                    public void run() {
                        textStatus.setText(msgconnected);

                        listViewPairedDevice.setVisibility(View.GONE);
                        inputPane.setVisibility(View.VISIBLE);
                    }});

                startThreadConnected(bluetoothSocket);
            }else{
                //fail
            }
        }

        public void cancel() {

            Toast.makeText(getApplicationContext(),
                    "close bluetoothSocket",
                    Toast.LENGTH_LONG).show();

            try {
                bluetoothSocket.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }    
        }    
    }

    /*
    ThreadConnected:
    Background Thread to handle Bluetooth data communication
    after connected
     */
    private class ThreadConnected extends Thread {
        private final BluetoothSocket connectedBluetoothSocket;
        private final InputStream connectedInputStream;
        private final OutputStream connectedOutputStream;

        public ThreadConnected(BluetoothSocket socket) {
            connectedBluetoothSocket = socket;
            InputStream in = null;
            OutputStream out = null;

            try {
                in = socket.getInputStream();
                out = socket.getOutputStream();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            connectedInputStream = in;
            connectedOutputStream = out;
        }

        @Override
        public void run() {
            byte[] buffer = new byte[1024];
            int bytes;

            while (true) {
                try {
                    bytes = connectedInputStream.read(buffer);
                    String strReceived = new String(buffer, 0, bytes);
                    final String msgReceived = String.valueOf(bytes) +
                            " bytes received:\n"
                            + strReceived;

                    runOnUiThread(new Runnable() {

                        @Override
                        public void run() {
                            textStatus.setText(msgReceived);

                        }});

                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();

                    final String msgConnectionLost = "Connection lost:\n"
                            + e.getMessage();
                    runOnUiThread(new Runnable(){

                        @Override
                        public void run() {
                            textStatus.setText(msgConnectionLost);
                        }});
                }
            }
        }

        public void write(byte[] buffer) {
            try {
                connectedOutputStream.write(buffer);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        public void cancel() {
            try {
                connectedBluetoothSocket.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

主要布局:

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="Please Choose "
        android:textStyle="bold" />

    <Button
        android:text="Button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button" />
</LinearLayout>

Activity 布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_bluetoothconnect"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.androidbtcontrol.bluetoothconnect">
    <TextView
        android:id="@+id/info"
        android:textStyle="bold|italic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <TextView
        android:id="@+id/status"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <ListView
        android:id="@+id/pairedlist"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <RelativeLayout
        android:id="@+id/inputpane"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:visibility="gone">
    </RelativeLayout>

    <SeekBar
        android:id="@+id/analogOut"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="99"
        android:progress="0"/>

    <ToggleButton
        android:text="ToggleButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/toggleButton" />    

</RelativeLayout>

Answer 1

这些是我从您提供的信息中发现的一些错误。发布 logcat 异常详细信息，以便我可以改进此解决方案。

1) 不要使用您自己的 onCreate 版本(在蓝牙 Activity 中)。一项 Activity 应该只有一个 onCreate 方法。您还需要将 @Override 前缀添加到 onCreate 方法中。您的代码包含错误的 onCreate2 和 onCreate3 方法。 这可能是崩溃的原因，因为当调用蓝牙 Activity 时，它找不到 onCreate 方法。

 @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

   //Keep your bluetooth related functionality here.


}

2)启动 Intent 时，您还需要指定源和目标。

Intent intent = new Intent(CallingActivity.this,CalledActivity.class);
startActivity(intent);