android 上架把log停掉

-dontskipnonpubliclibraryclasses
-dontobfuscate
-forceprocessing
-optimizationpasses 5
-keep class * extends android.app.Activity
-assumenosideeffects class android.util.Log {
public static *** d(…);
public static *** v(…);
}

編輯proguard-rules.pro

buildTypes {
release {
minifyEnabled true
shrinkResources false
proguardFiles getDefaultProguardFile(‘proguard-android-optimize.txt’), ‘proguard-rules.pro’
}
}

確認 build.gradle 裡面的 buildTypes 屬性

Android 開檔案出現權限問題 FileUriExposedException

除了設定以下policy外,

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);

還需要進行額外設定

try{
Method m = StrictMode.class.getMethod("disableDeathOnFileUriExposure");
m.invoke(null);
}catch(Exception e){
e.printStackTrace();
}

優化Android搜尋藍牙裝置方式(API 21)

Android 6.0(API 21)以後, 搜尋藍芽裝置的方式改成:

BluetoothAdapter.startScan (ScanCallback callback)

這種方式我一直用了很久, 也沒遇到問題.

直到有一個需求是隨時監控廣播封包,

這種寫法就會遇到問題, 無法快速取得周遭藍牙廣播資料, 因此需要修改寫法, 把能下的藥都下下去(但耗電):

final List<ScanFilter> filters = new ArrayList<>();
ScanFilter filter = new ScanFilter.Builder().build();
filters.add(filter);

final ScanSettings scanSettings =
        new ScanSettings.Builder() .setNumOfMatches(ScanSettings.MATCH_NUM_MAX_ADVERTISEMENT).setMatchMode(ScanSettings.MATCH_MODE_STICKY).setCallbackType(ScanSettings.CALLBACK_TYPE_ALL_MATCHES).setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY).build();


BluetoothAdapter.getBluetoothLeScanner().startScan(filters,scanSettings,mLeScanCallback);
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