Question

我正在使用DeviceListActivity来发现蓝牙设备。这是Android蓝牙聊天程序示例中使用的活动。

我在虚拟机上运行程序。

问题：当我开始扫描/发现蓝牙设备时：

enter image description here

它列出了重复的设备名称：

enter image description here

我有一个可被发现的设备但该程序不止一次列出它。

如何阻止列出重复的设备名称？

活动代码：

package com.example.android.BluetoothChat;

import java.util.Set;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;

/**
 * This Activity appears as a dialog. It lists any paired devices and
 * devices detected in the area after discovery. When a device is chosen
 * by the user, the MAC address of the device is sent back to the parent
 * Activity in the result Intent.
 */
public class DeviceListActivity extends Activity {
    // Debugging
    private static final String TAG = "DeviceListActivity";
    private static final boolean D = true;

    // Return Intent extra
    public static String EXTRA_DEVICE_ADDRESS = "device_address";

    // Member fields
    private BluetoothAdapter mBtAdapter;
    private ArrayAdapter<String> mPairedDevicesArrayAdapter;
    private ArrayAdapter<String> mNewDevicesArrayAdapter;

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

        // Setup the window
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setContentView(R.layout.device_list);

        // Set result CANCELED incase the user backs out
        setResult(Activity.RESULT_CANCELED);

        // Initialize the button to perform device discovery
        Button scanButton = (Button) findViewById(R.id.button_scan);
        scanButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                doDiscovery();
                v.setVisibility(View.GONE);
            }
        });

        // Initialize array adapters. One for already paired devices and
        // one for newly discovered devices
        mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
        mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);

        // Find and set up the ListView for paired devices
        ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
        pairedListView.setAdapter(mPairedDevicesArrayAdapter);
        pairedListView.setOnItemClickListener(mDeviceClickListener);

        // Find and set up the ListView for newly discovered devices
        ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
        newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
        newDevicesListView.setOnItemClickListener(mDeviceClickListener);

        // Register for broadcasts when a device is discovered
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        this.registerReceiver(mReceiver, filter);

        // Register for broadcasts when discovery has finished
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        this.registerReceiver(mReceiver, filter);

        // Get the local Bluetooth adapter
        mBtAdapter = BluetoothAdapter.getDefaultAdapter();

        // Get a set of currently paired devices
        Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();

        // If there are paired devices, add each one to the ArrayAdapter
        if (pairedDevices.size() > 0) {
            findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            }
        } else {
            String noDevices = getResources().getText(R.string.none_paired).toString();
            mPairedDevicesArrayAdapter.add(noDevices);
        }
    }

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

        // Make sure we're not doing discovery anymore
        if (mBtAdapter != null) {
            mBtAdapter.cancelDiscovery();
        }

        // Unregister broadcast listeners
        this.unregisterReceiver(mReceiver);
    }

    /**
     * Start device discover with the BluetoothAdapter
     */
    private void doDiscovery() {
        if (D) Log.d(TAG, "doDiscovery()");

        // Indicate scanning in the title
        setProgressBarIndeterminateVisibility(true);
        setTitle(R.string.scanning);

        // Turn on sub-title for new devices
        findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);

        // If we're already discovering, stop it
        if (mBtAdapter.isDiscovering()) {
            mBtAdapter.cancelDiscovery();
        }

        // Request discover from BluetoothAdapter
        mBtAdapter.startDiscovery();
    }

    // The on-click listener for all devices in the ListViews
    private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
        public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
            // Cancel discovery because it's costly and we're about to connect
            mBtAdapter.cancelDiscovery();

            // Get the device MAC address, which is the last 17 chars in the View
            String info = ((TextView) v).getText().toString();
            String address = info.substring(info.length() - 17);

            // Create the result Intent and include the MAC address
            Intent intent = new Intent();
            intent.putExtra(EXTRA_DEVICE_ADDRESS, address);

            // Set result and finish this Activity
            setResult(Activity.RESULT_OK, intent);
            finish();
        }
    };

    // The BroadcastReceiver that listens for discovered devices and
    // changes the title when discovery is finished
    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // If it's already paired, skip it, because it's been listed already
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
                }
            // When discovery is finished, change the Activity title
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                setProgressBarIndeterminateVisibility(false);
                setTitle(R.string.select_device);
                if (mNewDevicesArrayAdapter.getCount() == 0) {
                    String noDevices = getResources().getText(R.string.none_found).toString();
                    mNewDevicesArrayAdapter.add(noDevices);
                }
            }
        }
    };

}

修改这个问题在我的真实设备（智能手机）上消失了。我不知道为什么模拟器有这样的问题！

Answer 1

简单。要进行过滤，请使用Set。

实施例

HashSet

在HashSet上添加蓝牙地址，并使用方法contains()进行验证。

如果contains()返回false，则将蓝牙数据添加到列表

如果contains()返回true，则不要将蓝牙数据添加到列表中

Answer 2

将此内容写入 ACTION_FOUND。

if (mNewDevicesArrayAdapter.size() < 1) {
    mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
    mNewDevicesArrayAdapter.notifyDataSetChanged();
}
else {
    boolean flag = true;    // flag to indicate that particular device is already in the arlist or not
    for(int i = 0; i<mNewDevicesArrayAdapter.size();i++)
    {
        if(device.getAddress().equals(mNewDevicesArrayAdapter.get(i).getAddress()))
        {
            flag = false;
        }
    }
    if(flag == true)
    {
        mNewDevicesArrayAdapter.add(device.getName()+"\n"+device.getAddress());

        mNewDevicesArrayAdapter.notifyDataSetChanged();
    }
}

Answer 3

这个对我有用

public class MainActivity extends ActionBarActivity {

    private ListView listView;
    private ArrayList<String> mDeviceList = new ArrayList<String>();
    private BluetoothAdapter mBluetoothAdapter;

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

        listView = (ListView) findViewById(R.id.listView);

        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        mBluetoothAdapter.startDiscovery();

        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        registerReceiver(mReceiver, filter);

    }


    @Override
    protected void onDestroy() {
        unregisterReceiver(mReceiver);
        super.onDestroy();
    }

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent
                        .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                mDeviceList.add(device.getName() + "\n" + device.getAddress());
                Log.i("BT", device.getName() + "\n" + device.getAddress());
                listView.setAdapter(new ArrayAdapter<String>(context,
                        android.R.layout.simple_list_item_1, mDeviceList));
            }
        }
    };

Answer 4

在BluetoothDevice.ACTION_FOUND的onReceive中，在将蓝牙设备添加到Arraylist之前，请使用ArrayList的contains（）方法检查Arraylist是否已经包含该设备。仅当contains（）返回false时，才将设备添加到列表中。

Code is as below:

List<BluetoothDevice> availableDevices = new ArrayList<>();

 class BluetoothReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action != null) {
            switch (action) {
                case BluetoothDevice.ACTION_FOUND: {
                    // Discovery has found a device. Get the BluetoothDevice
                    // object and its info from the Intent.
                    BluetoothDevice bluetoothDevice =
                            intent.getParcelableExtra(BluetoothDevice
                                    .EXTRA_DEVICE);

                   //Add the device to the list only if contains() returns false.

                    if (!availableDevices.contains(bluetoothDevice)) {
                        availableDevices.add(bluetoothDevice);
                    }

                    displayAvailableDevices();
                    break;
                }

Answer 5

对我有用

    @Override
public void onDeviceDiscovered(BluetoothDevice device) {
    listener.endLoading(true);
    devices.contains(device);
    //======================To add only unique device not repeating same device in listView========================
    if(  devices.contains(device)){

    }else {
        devices.add(device);
    }

    //======================End of add only unique device not repeating same device in listView====================
    notifyDataSetChanged();
}

发现蓝牙设备会列出重复的名称

5 个答案:

实施例