android - 如何在列表中仅显示一台设备？

Question

我想做我的蓝牙列表只显示一个设备。我试过了，我用开关盒做到了。但是我们使用了break，所以我的程序关闭了。如果我使用 if-else，我的程序将再次关闭。这是我的原始代码：

public void onReceive(Context context, Intent intent) {
                final String action = intent.getAction();
                Log.d(TAG, "onReceive: ACTION FOUND.");
                //  mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

                    if (action.equals(BluetoothDevice.ACTION_FOUND)) {
                        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                       mBTDevices.add(device);
                            Log.d(TAG, "onReceive: " + device.getName() + ": " + device.getAddress());
                            mDeviceListAdapter = new DeviceListAdapter(getActivity(), R.layout.device_adapter_view, mBTDevices);
                            lvData.setAdapter(mDeviceListAdapter);


                    }

这是开关盒：

public void onReceive(Context context, Intent intent) {
                final String action = intent.getAction();
                Log.d(TAG, "onReceive: ACTION FOUND.");
                //  mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

                    if (action.equals(BluetoothDevice.ACTION_FOUND)) {
                        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                        switch (String.valueOf(device.getName())) {

                            case "MyDevice" :
                                mBTDevices.add(device);
                            Log.d(TAG, "onReceive: " + device.getName() + ": " + device.getAddress());
                            mDeviceListAdapter = new DeviceListAdapter(getActivity(), R.layout.device_adapter_view, mBTDevices);
                            lvData.setAdapter(mDeviceListAdapter);
                            break;
                        }
                    }

            }

这是我的 Logcat：

Process: com.example.duygu.mybluetoothdevicelist, PID: 11510
    java.lang.RuntimeException: Error receiving broadcast Intent { act=android.bluetooth.device.action.FOUND flg=0x10 (has extras) } in com.example.duygu.mybluetoothdevicelist.BluetoothListFragment$1@33c56d3
        at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:935)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5525)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:730)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:620)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.hashCode()' on a null object reference
        at com.example.duygu.mybluetoothdevicelist.BluetoothListFragment$1.onReceive(BluetoothListFragment.java:108)
        at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:925)

标签： android