Android Functions

Convert string to int

Integer.parseInt()

Set background for textview

setBackgroundColor(Color.YELLOW);

Show a toast

Toast toast = Toast.makeText(getApplicationContext(), "This is a message displayed in a Toast", Toast.LENGTH_SHORT); toast.show();

Android Studio

  • Build debug apk
    android studio build debug apk

ADB Commands

  • Install apk 
    MyApplication\app\build\outputs\apk\debug>adb install app-debug.apk
  • Install apk Failure [INSTALL_FAILED_ALREADY_EXISTS]. You have to uninstall the applicatoin first.
  • Uninstall apk 
    MyApplication\app\build\outputs\apk\debug>adb uninstall com.example.application
  • Install apk Failure [INSTALL_FAILED_UPDATE_INCOMPATIBLE]. You have installed a debug application on the device. You need to uninstall it then install the release application.
  • Install release apk Failure [INSTALL_PARSE_FAILED_NO_CERTIFICATES].APK Signature Scheme v2 is a new feature in android 7.0. You fix it by checked signature verions V1 optioin. 
    MyApplication\app\release>adb install app-release.apk

    android studio v1 signature

JNI Functions

  • Load JNI function from MyApplication\app\libs\JNILibrary.so.
  • Find keyword System.loadLibrary(“JNILibrary”);