float dp = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 30f, getResources().getDisplayMetrics());
方法二
int px1 = getResources().getDimensionPixelSize(R.dimen.dp_10); int px2 = getResources().getDimensionPixelOffset(R.dimen.dp_20); float dp = getResources().getDimension(R.dimen.dp_10);