Android 10基站信息变化适配

Posted 2023-02-27 Alex_MaHao

在android上基站信息的获取可以通过方法：

mTelephonyManager.getAllCellInfo()

但在android10上，该方法有所变动。

Beginning with Android Q, if this API results in a change of the cached CellInfo, that change will be reported via onCellInfoChanged().
Apps targeting Android Q or higher will no longer trigger a refresh of the cached CellInfo by invoking this API. Instead, those apps will receive the latest cached results, which may not be current. Apps targeting Android Q or higher that wish to request updated CellInfo should call requestCellInfoUpdate(); however, in all cases, updates will be rate-limited and are not guaranteed. To determine the recency of CellInfo data, callers should check CellInfo#getTimeStamp().
This method returns valid data for devices with FEATURE_TELEPHONY. In cases where only partial information is available for a particular CellInfo entry, unavailable fields will be reported as android.telephony.CellInfo#UNAVAILABLE. All reported cells will include at least a valid set of technology-specific identification info and a power level measurement.

在应用target < 29时，调用该方法会立即刷新基站信息。但在target >=29时，调用该方法不会在立即刷新基站信息，可能获取的是一个缓存的基站信息

如果对基站信息的实时性要求不高，通过上面的方法即可。

但是如果对基站信息要求较高，需要通过requestCellInfoUpdate去刷新基站信息，该方法介绍如下：

Requests all available cell information from the current subscription for observed camped/registered, serving, and neighboring cells.
Any available results from this request will be provided by calls to onCellInfoChanged() for each active subscription.
This method returns valid data for devices with FEATURE_TELEPHONY. On devices that do not implement this feature, the behavior is not reliable.

该方法会回调刷新后的基站信息，但是通过实验发现，回调的基站信息并不完整，再调用getAllCellInfo获取更完整。

所以最后的逻辑如下：

        final CountDownLatch countDownLatch = new CountDownLatch(1);
        mTelephonyManager.requestCellInfoUpdate(mRequestCellExecutor, new TelephonyManager.CellInfoCallback() 
            @Override
            public void onCellInfo(@NonNull List<CellInfo> cellInfo) 
                countDownLatch.countDown();
            

            @Override
            public void onError(int errorCode, @Nullable Throwable detail) 
                super.onError(errorCode, detail);
                countDownLatch.countDown();
            
        );
        // 经过测试，一般为30ms左右
        boolean result = countDownLatch.await(1000, TimeUnit.MILLISECONDS);

        List<CellInfo> allCellInfo = mTelephonyManager.getAllCellInfo();