Android – DialogFragment setStyle


//1 -> style = DialogFragment.STYLE_NO_TITLE
//2 -> style = DialogFragment.STYLE_NO_FRAME
//3 -> style = DialogFragment.STYLE_NO_INPUT
//4 -> style = DialogFragment.STYLE_NORMAL
//            --
//4 -> theme =
//5 -> theme =
//6 -> theme =
//7 -> theme =

Android – Calculando a intensidade do sinal wifi (Getting WiFi signal strength in Android)

android wifi

WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
int numberOfLevels = 5;
WifiInfo wifiInfo = wifiManager.getConnectionInfo();Referência
int level = WifiManager.calculateSignalLevel(wifiInfo.getRssi(), numberOfLevels);


Android – Desabilitar o recurso multi window programaticamente (Disable multi window feature programatically)


Normalmente presente em dispositivos da samsung. Para desabilitar o recurdo multi-window basta executar o seguinte comando:

// requer permissão: android:name="android.permission.WRITE_SETTINGS"
// 0=desabilitado ; 1=habilitado
Settings.System.putInt(contentResolver, "multi_window_enabled", 0)

Android – Esconder o teclado do android programaticamente ‘forçado’ (Hide keyboard programmatically)


easy workaround:

           InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
           imm.hideSoftInputFromWindow(getActivity().getCurrentFocus().getWindowToken(), 0);

Android – Como converter um byte[] em um objeto Mat utilizando o OpenCV no Android (How to get the Mat object from the Byte[] in openCV android?)

Simples assim:

Mat mat = Imgcodecs.imdecode(
    new MatOfByte(bytes), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED

Como converter um Bitmap em um objeto Mat:


Mat mat = new Mat();    
Bitmap bmp32 = bmp.copy(Bitmap.Config.ARGB_8888, true);
Utils.bitmapToMat(bmp32, mat);

Android – Detecção facial utilizando o OpenCV (OpenCV in Android Studio with face detect)


Detecção facial utilizando OpenCV no Android – OpenCV in Android Studio with face detect

This application is a sample Android Studio project (tested on gradle 3.0.1) with ‘Android SDK OpenCV 3.3.1′



Here is how to use this project to run native OpenCV code.

  • Make sure you have Android SDK up to date, with NDK installed
  • Download latest OpenCV SDK for Android from and decompress the zip file.
  • Clone this project
  • Create a symlink named jniLibs in app/src/main that points to YOUR_OPENCV_SDK/sdk/native/libs
  • In app/CMakeLists.txt change line 9 to points to YOUR_OPENCV_SDK/sdk/native/jni/include
  • Sync gradle
  • Run the application