文字

文字绘制：

		String text = getResources().getString(R.string.scan_text);
		Rect rect = new Rect();		
		paint.setColor(Color.WHITE);
		paint.setTextSize(25);
		paint.setAlpha(0xb0);
		paint.setTypeface(Typeface.create("System", Typeface.BOLD));
		paint.getTextBounds(text, 0, text.length(), rect);	//使rect获得text文字宽度，以便文字居中绘制	
		canvas.drawText(text, (width-rect.width())/2, (float) (frame.bottom + 50), paint);