最近在對(duì)接手環(huán)的第三方SDK，功能對(duì)接基本都是設(shè)置一個(gè)回調(diào)監(jiān)聽(tīng)，然后調(diào)用對(duì)應(yīng)的SDK方法，最后在回調(diào)方法中實(shí)現(xiàn)我們自己的邏輯處理。對(duì)接過(guò)程中有一個(gè)設(shè)備掃描激活頁(yè)面，按照開(kāi)發(fā)文檔也就是調(diào)用SDK的某個(gè)方法（參數(shù)里面有一個(gè)回調(diào)監(jiān)聽(tīng)），很簡(jiǎn)單。然而，在關(guān)閉這個(gè)頁(yè)面之后，回調(diào)方法卻還能被調(diào)用，之后LeakCanary也報(bào)了這個(gè)頁(yè)面存在內(nèi)存泄漏。進(jìn)入SDK中查看了一下該方法，發(fā)現(xiàn)傳入SDK的回調(diào)監(jiān)聽(tīng)都會(huì)被置為static，從而一直持有調(diào)用Activity的引用，導(dǎo)致Activity無(wú)法被釋放而產(chǎn)生內(nèi)存泄漏。為了解決這個(gè)問(wèn)題，剛開(kāi)始寫了一個(gè)靜態(tài)內(nèi)部類來(lái)解決，但后面發(fā)現(xiàn)幾乎所有傳入SDK的回調(diào)監(jiān)聽(tīng)都會(huì)被置為static，所以只好對(duì)SDK調(diào)用方法統(tǒng)一再進(jìn)行一層封裝管理。

SDK調(diào)用方法統(tǒng)一管理

public class ClingManager {

    private OnScanClingDeviceListener onScanClingDeviceListener;
    private Handler mHandler;

    private static class ClingManagerHolder {
        public static final ClingManager INSTANCE = new ClingManager();
    }

    private ClingManager() {
        mHandler = new Handler();
    }

    public static ClingManager getInstance() {
        return ClingManagerHolder.INSTANCE;
    }

    /**
     * 添加掃描設(shè)備監(jiān)聽(tīng)
     * @param listener
     */
    public void addScanClingDeviceListener(OnScanClingDeviceListener listener) {
        onScanClingDeviceListener = listener;
    }

    /**
     * 移除掃描設(shè)備監(jiān)聽(tīng)
     */
    public void removeScanClingDeviceListener() {
        onScanClingDeviceListener = null;
    }

    /**
     * 掃描設(shè)備
     */
    public void scanClingDevice() {
        ClingSdk.startScan(10 * 60 * 1000, new OnBleListener.OnScanDeviceListener() { 
            @Override
            public void onBleScanUpdated(Object o) {
                //藍(lán)牙連接成功后，不會(huì)再掃描
                if (o == null) {
                    return;
                }
                final ArrayList<BluetoothDeviceInfo> arrayList = (ArrayList<BluetoothDeviceInfo>) o;
                if (arrayList.size() > 0 && onScanClingDeviceListener != null) {
                    mHandler.post(new Runnable() {
                        @Override
                        public void run() {
                            onScanClingDeviceListener.onScanClingDevice(arrayList);
                        }
                    });
                }
            }
        });
    }

    /**
     * 掃描設(shè)備監(jiān)聽(tīng)
     */
    public interface OnScanClingDeviceListener {
        void onScanClingDevice(ArrayList<BluetoothDeviceInfo> clingDeviceList);
    }
}

Activity中調(diào)用

需要注意的就是要在Activity的onDestroy生命周期方法中將掃描設(shè)備回調(diào)監(jiān)聽(tīng)移除。

public class BindActivity {

    private Handler mHandler = new Handler();

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

        initDataCallBack();
    }

    @Override
    protected void onStart() {
        super.onStart();
        registerReceiver(mBleReceiver, new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED));
        if (!BleUtil.isBleOpen()) {
            showOpenBleMsg();
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        startScan();
    }

    private void showOpenBleMsg() {
        Snackbar.make(ripple, "請(qǐng)打開(kāi)藍(lán)牙來(lái)綁定手環(huán)/手表", Snackbar.LENGTH_INDEFINITE)
                .setAction("打開(kāi)藍(lán)牙", new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent mIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                        startActivityForResult(mIntent, REQUEST_OPEN_BLE);
                    }
                })
                .show();
    }

    private void initDataCallBack() {
        // 掃描設(shè)備回調(diào)監(jiān)聽(tīng)
        ClingManager.getInstance().addScanClingDeviceListener(new ClingManager.OnScanClingDeviceListener() {
            @Override
            public void onScanClingDevice(ArrayList<BluetoothDeviceInfo> clingDeviceList) {
                for (BluetoothDeviceInfo clingDevice : clingDeviceList) {
                    if (TextUtils.equals(clingDevice.getmBleDevice().getName(), "PBAND 9048")) {
                        ClingSdk.stopScan();
                        ClingManager.getInstance().registerClingDevice(clingDevice);
                        break;
                    }
                }
    }

    private void startScan() {
        ClingSdk.stopScan();
        ClingSdk.setClingDeviceType(ClingSdk.CLING_DEVICE_TYPE_ALL);
        ClingManager.getInstance().scanClingDevice();
    }

    private BroadcastReceiver mBleReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            int blueState = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 0);
            switch (blueState) {
                case BluetoothAdapter.STATE_OFF:
                    break;
                case BluetoothAdapter.STATE_TURNING_ON:
                    break;
                case BluetoothAdapter.STATE_ON:
                    mHandler.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            startScan();
                        }
                    }, 1000);
                    break;
                case BluetoothAdapter.STATE_TURNING_OFF:
                    break;
                default:
                    break;
            }
        }
    };

    @Override
    protected void onPause () {
        super.onPause();
    }

    @Override
    protected void onStop() {
        super.onStop();
        unregisterReceiver(mBleReceiver);
    }

    @Override
    protected void onDestroy () {
        super.onDestroy();
        ClingManager.getInstance().removeScanClingDeviceListener();
    }
}