SeekBar listener Android Example Source

getContext() getApplicationContext() method Java Android example source

Context myContext_1 = ThisClassName.this; // to open a Dialog

Context myContext_2 = getContext();

Context myContext_3 = this.getContext();

Context myContext_4 = this;

Context myContext_5 = this.getApplicationContext ();





	OnClickListener getImageBtnOnClick = new OnClickListener() {

		public void onClick(View view) {

			Context context = view.getContext();



		}

	};

// Toast 

Toast.makeText(getApplicationContext(), "Context == getApplicationContext "

   , Toast.LENGTH_SHORT).show();







// store Context in public class

public class MyActivity extends Activity { 

    public static Context myCnt = null; 

    ... 

    protected void onCreate(Bundle icicle) { 

         ... 

        myCnt = this; 

        MyStorage.setContext(myCnt); 

        // or

        // MyStorage.setContext(this);        

        

        // cntxFromStorage == this

        Context cntxFromStorage = MyStorage.getContext();

        ... 

        }; 

    }; 

    

public class MyStorage

{

    private static Context cntStorageContext = null;

 	  

     

    public static Context getContext() { 

        return cntStorageContext;

     }

        

    public static void setContext(Context context) {

	 MyStorage.cntStorageContext = context;

	  }





    }; 



class DataBaseHelper extends SQLiteOpenHelper {

// get MyActivity context 

Context cnt = MyStorage.getContext();



}

Google Android example source code - is text changed in EditText ?

EditText hEditText;

// TextChanged in onCreate

hEditText = (EditText)findViewById(R.id.idEditText);

hEditText.addTextChangedListener(new TextWatcher() {

	public void afterTextChanged(Editable str) {

	}



	public void beforeTextChanged(CharSequence s, int start, int count,

			int after) {

	}



	public void onTextChanged(CharSequence sq, int start, int before,

			int count) {

	}

});

Kvalitní mobilní telefon pro rok 2012 by měl mít tyto, nebo ještě lepší parametry.
Značka Samsung , HTC, LG, Motorola, Sony Ericsson, ZTE Blade
Verze operačního systému Android 2.2 a vyšší.
Procesor a jeho frekvence Qualcomm 800MHz a vyšší.
Paměť RAM 512MB a více.
Paměť ROM 512MB.
Displej a jeho rozlišení 4,3 palce rozlišení 480x800 pixelů pro snadné ovládání a čtení a schopnost zobrazit 16 milionů barev.
Technologie 3G data, WiFi, BlueTooth, GPS přijímač, fotoaparát 3 Mpix, autofokus, diodový blesk.
Výdrž baterie minimálně 1 den a více.
3G internet.

Copy file to another

        File path = Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES);
        File file = new File(path, "MyPicture.jpg");
           // the Pictures directory exists? 
            path.mkdirs();
            InputStream is = getResources().openRawResource(R.drawable.flower_blue);
            OutputStream os = new FileOutputStream(file);
            byte[] data = new byte[is.available()];
            is.read(data);
            os.write(data);
            is.close();
            os.close();

Copy and compress file

Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
					R.drawable.flower_blue);

try {
	 FileOutputStream out = new FileOutputStream("new_bitmap.jpg");
		bitmapOrg.compress(Bitmap.CompressFormat.JPEG, 90, out);
} catch (Exception e) {
	e.printStackTrace();
	Log.e("saveBitmap", e.getMessage());
} 

Throws multiple exceptions Java example source code

	public void callFc() 
	throws IndexOutOfBoundsException, ArithmeticException
	{
         // my code for example:
         String[] sArray = {"aa","bb"};
         String str = sArray[5]; // IndexOutOfBoundsException

         int n = 5 / 0; // ArithmeticException
        }

public void someFC (){
try{
     callFc();
    }
 catch(IndexOutOfBoundsException e){
      Log.e("TAG", e.toString());
  }
 catch(ArithmeticException e2){ 
      Log.e2("TAG",e2.toString()); 
  }
}