Download file from root Android device Windows

The exact physical pixels per inch of the screen
Get size of pixel
Get DPI
Get count of pixels per inch

        float mXDpi;
        float mYDpi;
           DisplayMetrics metrics = new DisplayMetrics();
            getWindowManager().getDefaultDisplay().getMetrics(metrics);
            mXDpi = metrics.xdpi; // The exact physical pixels per inch of the screen in the X dimension. 
            mYDpi = metrics.ydpi;
          float  mMetersToPixelsX = mXDpi / 0.0254f; // 1 inch == 0.0254 metre
          float  mMetersToPixelsY = mYDpi / 0.0254f;

I tried this Eclipse and work fine:
Eclipse Classic
//www.filehippo.com/download_eclipse_classic_32/

Eclipse Juno
Eclipse Helios

//developer.android.com/tools/sdk/eclipse-adt.html

AlertDialog like MessageBox by WinApi:
If error: Unable to add window -- token null is not for an application
try change get Context.

// you can put this text into some function body or case in switch statement
                new AlertDialog.Builder(this)
                    .setMessage("Hello boys!!!")
                    .setPositiveButton("OK", null)
                    .show();

Context context = getApplicationContext();
	AlertDialog.Builder builder = new AlertDialog.Builder(context);
	builder.setTitle("Select font size");
	final CharSequence[] chsSize= { "Small", "Medium", "Large"};
	builder.setSingleChoiceItems(chsSize, 0 /*sel.item*/, 
	new DialogInterface.OnClickListener() {
 	    public void onClick(DialogInterface dialog, int item) {
	    		 Toast.makeText(context, "Hello from dialog!!!", Toast.LENGTH_SHORT).show();
	        dialog.dismiss();
	    }
	});
	AlertDialog alert = builder.create();
	alert.show();
    

Download image file from URL to ImageView Java Android source example code.

Context context = thisClass.this;
Drawable image = ImageOperations(context,
"//www.okhelp.cz/images/android/ad_4.png"
,"image.jpg");
ImageView imgView;
imgView = (ImageView)findViewById(R.id.idImageView);
imgView.setImageDrawable(image);

	private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
		try {
			InputStream is = (InputStream) this.fetch(url);
			Drawable d = Drawable.createFromStream(is, "src");
			return d;
		} catch (MalformedURLException e) {
			e.printStackTrace();
			return null;
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
	}

	public Object fetch(String address) throws MalformedURLException,IOException {
		URL url = new URL(address);
		Object content = url.getContent();
		return content;
	}

drawOval(), setStrokeWidth(), setStyle()

public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}

		@Override
		protected void onDraw(Canvas canvas) {

			canvas.drawColor(Color.CYAN);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStyle(Paint.Style.STROKE); 
			p.setStrokeWidth(4.5f);
			// opacity
			//p.setAlpha(0x80); //
 
			canvas.drawOval(new RectF(50, 50, 20, 40), p);;
		}

	}
}