Android Studio failed to convert drawable into a drawable

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.YELLOW);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStrokeWidth(4.5f);
			// opacity
			p.setAlpha(0x80); //
			// drawLine (float startX, float startY, float stopX, float stopY,
			// Paint paint)
			canvas.drawLine(0, 0, 40, 40, p);
			canvas.drawLine(40, 0, 0, 40, p);

		}

	}
}

// start_dark.png is stored in path	/package_name/res/drawable/start_dark.png
Drawable dw = getApplicationContext().getResources().getDrawable(R.drawable.start_dark);
Button hButtonStart = (Button)findViewById(R.id.buttonStart);
hButtonStart.setCompoundDrawablesWithIntrinsicBounds(dw, null, null, null);

Cursor cursor = managedQuery(...........,,,,);
// Specify the columns we want to display in the result
            String[] from = new String[] { KEY_WORD,
                                           KEY_DEFINITION };

            // Specify the corresponding layout elements where we want the columns to go
            int[] to = new int[] { R.id.word,
                                   R.id.definition };
// deprecated 
 SimpleCursorAdapter words =
            new SimpleCursorAdapter(this,
                    R.layout.result, cursor, from, to);
// working
 SimpleCursorAdapter words =
            new SimpleCursorAdapter(this,
                    R.layout.result, cursor, from, to, 0); // to, 0!!!!


//working in Fragment
SimpleCursorAdapter  mAdapter = new SimpleCursorAdapter(getActivity(),
                android.R.layout.simple_list_item_2, null,
                new String[] { "name", "age" }, // cursor parameters
                new int[] { android.R.id.text1, android.R.id.text2 }, 0);