如何在 Android Studio 上使用 TaskStackBuilder 消除错误?

How do I get rid of errors using TaskStackBuilder on Android Studio?

我正在 Android 工作室制作应用程序。我的应用程序与 RFDuino 微控制器板建立了蓝牙连接。我想添加一个通知,当用户失去蓝牙信号时通知他们。我希望通知使用振动 and/or 声音。我尝试了几种方法,但无法让它们编译。最近,我使用了 TaskStackBuilder,但我不断收到错误。由于某种原因,它无法识别 TaskStackBuilder 中的某些方法。任何想法或简单的通知代码?

C:\Users\Trisha\AndroidStudioProjects\SmartB3\app\src\main\java\smartb\smartb3\MainActivity.java

错误:(44, 32) 错误:需要标识符

错误:(44, 48) 错误:需要标识符

错误:(46, 31) 错误:需要标识符

错误:(46, 44) 错误:需要标识符

错误:(48, 30) 错误:需要标识符

错误:(48, 50) 错误:需要标识符

package smartb.smartb3;


import android.app.Activity;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.TaskStackBuilder;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.smartb.smartb3.R;

public class MainActivity extends Activity implements BluetoothAdapter.LeScanCallback {
    // State machine

    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this)
            .setSmallIcon(R.drawable.ic_launcher)
            .setContentTitle("SMARTB")
            .setContentText("You left your USB!");
    // Creates an explicit intent for an Activity in your app
    Intent resultIntent = new Intent(this, ResultActivity.class);

    // The stack builder object will contain an artificial back stack for the
    // started Activity.
    // This ensures that navigating backward from the Activity leads out of
    // your application to the Home screen.
    TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
    /* Adds the back stack for the Intent (but not the Intent itself) */
    stackBuilder.addParentStack(ResultActivity.class);
    // Adds the Intent that starts the Activity to the top of the stack
    stackBuilder.addNextIntent(resultIntent);
    PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);
    mBuilder.setContentIntent(resultPendingIntent);
    NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

    final private static int STATE_BLUETOOTH_OFF = 1;
    final private static int STATE_DISCONNECTED = 2;
    final private static int STATE_CONNECTING = 3;
    final private static int STATE_CONNECTED = 4;

    private int state;

    private boolean scanStarted;
    private boolean scanning;

    private BluetoothAdapter bluetoothAdapter;
    private BluetoothDevice bluetoothDevice;

    private RFduinoService rfduinoService;

    private Button enableBluetoothButton;
    private TextView scanStatusText;
    private Button scanButton;
    private TextView deviceInfoText;
    private TextView connectionStatusText;
    private Button connectButton;
    private EditData valueEdit;
    private Button sendZeroButton;
    private Button sendValueButton;
    private Button clearButton;
    private LinearLayout dataLayout;


    final BluetoothAdapter.LeScanCallback callback;

    private final BroadcastReceiver bluetoothStateReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 0);
            if (state == BluetoothAdapter.STATE_ON) {
                upgradeState(STATE_DISCONNECTED);
            } else if (state == BluetoothAdapter.STATE_OFF) {
                downgradeState(STATE_BLUETOOTH_OFF);
            }
        }
    };

    private final BroadcastReceiver scanModeReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            scanning = (bluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_NONE);
            scanStarted &= scanning;
            updateUi();
        }
    };

    private final ServiceConnection rfduinoServiceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            rfduinoService = ((RFduinoService.LocalBinder) service).getService();
            if (rfduinoService.initialize()) {
                if (rfduinoService.connect(bluetoothDevice.getAddress())) {
                    upgradeState(STATE_CONNECTING);
                }
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            rfduinoService = null;
            downgradeState(STATE_DISCONNECTED);
            // mId allows you to update the notification later on.
            int mId = 0;
            mNotificationManager.notify(mId, mBuilder.build());

        }

    };

    private final BroadcastReceiver rfduinoReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (RFduinoService.ACTION_CONNECTED.equals(action)) {
                upgradeState(STATE_CONNECTED);
            } else if (RFduinoService.ACTION_DISCONNECTED.equals(action)) {
                downgradeState(STATE_DISCONNECTED);
            } else if (RFduinoService.ACTION_DATA_AVAILABLE.equals(action)) {
                addData(intent.getByteArrayExtra(RFduinoService.EXTRA_DATA));
            }
        }
    };

    public MainActivity() {
        callback = null;
    }

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

        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

        // Bluetooth
        enableBluetoothButton = (Button) findViewById(R.id.enableBluetooth);
        enableBluetoothButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                enableBluetoothButton.setEnabled(false);
                enableBluetoothButton.setText(
                        bluetoothAdapter.enable() ? "Enabling bluetooth..." : "Enable failed!");
            }
        });

        // Find Device
        scanStatusText = (TextView) findViewById(R.id.scanStatus);

        scanButton = (Button) findViewById(R.id.scan);
        scanButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                scanStarted = true;
                bluetoothAdapter.startLeScan(callback);
            }
        });

        // Device Info
        deviceInfoText = (TextView) findViewById(R.id.deviceInfo);

        // Connect Device
        connectionStatusText = (TextView) findViewById(R.id.connectionStatus);

        connectButton = (Button) findViewById(R.id.connect);
        connectButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                v.setEnabled(false);
                connectionStatusText.setText("Connecting...");
                Intent rfduinoIntent = new Intent(MainActivity.this, RFduinoService.class);
                bindService(rfduinoIntent, rfduinoServiceConnection, BIND_AUTO_CREATE);
            }
        });

        // Send
        valueEdit = (EditData) findViewById(R.id.value);
        valueEdit.setImeOptions();
        valueEdit.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_SEND) {
                    sendValueButton.callOnClick();
                    return true;
                }
                return false;
            }
        });

        sendZeroButton = (Button) findViewById(R.id.sendZero);
        sendZeroButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                rfduinoService.send(new byte[]{0});
            }
        });

        sendValueButton = (Button) findViewById(R.id.sendValue);
        sendValueButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                rfduinoService.send(valueEdit.getData());
            }
        });

        // Receive
        clearButton = (Button) findViewById(R.id.clearData);
        clearButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dataLayout.removeAllViews();
            }
        });

        dataLayout = (LinearLayout) findViewById(R.id.dataLayout);
    }

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

        registerReceiver(scanModeReceiver, new IntentFilter(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED));
        registerReceiver(bluetoothStateReceiver, new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED));
        registerReceiver(rfduinoReceiver, RFduinoService.getIntentFilter());

        updateState(bluetoothAdapter.isEnabled() ? STATE_DISCONNECTED : STATE_BLUETOOTH_OFF);
    }

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

        bluetoothAdapter.stopLeScan(this);

        unregisterReceiver(scanModeReceiver);
        unregisterReceiver(bluetoothStateReceiver);
        unregisterReceiver(rfduinoReceiver);
    }

    private void upgradeState(int newState) {
        if (newState > state) {
            updateState(newState);
        }
    }

    private void downgradeState(int newState) {
        if (newState < state) {
            updateState(newState);
        }
    }

    private void updateState(int newState) {
        state = newState;
        updateUi();
    }

    private void updateUi() {
        // Enable Bluetooth
        boolean on = state > STATE_BLUETOOTH_OFF;
        enableBluetoothButton.setEnabled(!on);
        enableBluetoothButton.setText(on ? "Bluetooth enabled" : "Enable Bluetooth");
        scanButton.setEnabled(on);

        // Scan
        if (scanStarted && scanning) {
            scanStatusText.setText("Scanning...");
            scanButton.setText("Stop Scan");
            scanButton.setEnabled(true);
        } else if (scanStarted) {
            scanStatusText.setText("Scan started...");
            scanButton.setEnabled(false);
        } else {
            scanStatusText.setText("");
            scanButton.setText("Scan");
            scanButton.setEnabled(true);
        }

        // Connect
        boolean connected = false;
        String connectionText = "Disconnected";
        if (state == STATE_CONNECTING) {
            connectionText = "Connecting...";
        } else if (state == STATE_CONNECTED) {
            connected = true;
            connectionText = "Connected";
        }
        connectionStatusText.setText(connectionText);
        connectButton.setEnabled(bluetoothDevice != null && state == STATE_DISCONNECTED);

        // Send
        sendZeroButton.setEnabled(connected);
        sendValueButton.setEnabled(connected);
    }

    private void addData(byte[] data) {
        View view = getLayoutInflater().inflate(android.R.layout.simple_list_item_2, dataLayout, false);

        TextView text1 = (TextView) view.findViewById(android.R.id.text1);
        text1.setText(HexAsciiHelper.bytesToHex(data));

        String ascii = HexAsciiHelper.bytesToAsciiMaybe(data);
        if (ascii != null) {
            TextView text2 = (TextView) view.findViewById(android.R.id.text2);
            text2.setText(ascii);
        }

        dataLayout.addView(
                view, LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
    }

    @Override
    public void onLeScan(BluetoothDevice device, final int rssi, final byte[] scanRecord) {
        bluetoothAdapter.stopLeScan(this);
        bluetoothDevice = device;

        MainActivity.this.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                deviceInfoText.setText(
                        BluetoothHelper.getDeviceInfoText(bluetoothDevice, rssi, scanRecord));
                updateUi();
            }
        });
    }
}

我认为您需要先了解您的代码是如何工作的。

您正在方法之外编写代码。建议先学习Java的基础再从学习Android.

开始

你在这种情况下的问题是以下几行应该在这样的方法中:

public void sendNotification() {

NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this)
                .setSmallIcon(R.drawable.ic_launcher)
                .setContentTitle("SMARTB")
                .setContentText("You left your USB!");
// Creates an explicit intent for an Activity in your app
Intent resultIntent = new Intent(this, ResultActivity.class);

// The stack builder object will contain an artificial back stack for the
// started Activity.
// This ensures that navigating backward from the Activity leads out of
// your application to the Home screen.
TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
/* Adds the back stack for the Intent (but not the Intent itself) */
stackBuilder.addParentStack(ResultActivity.class);
// Adds the Intent that starts the Activity to the top of the stack
stackBuilder.addNextIntent(resultIntent);
PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);
mBuilder.setContentIntent(resultPendingIntent);
NotificationManager mNotificationManager = (NotificationManager) 

getSystemService(Context.NOTIFICATION_SERVICE);
}

并在需要的地方调用这个方法。