Custom view subtotal

1.java Dimensions used in code , Avoid ： Don't reverse the order of the parameters

- setTextSize(TypedValue.COMPLEX_UNIT_PX,15); //22 Pixels  
- setTextSize(TypedValue.COMPLEX_UNIT_SP,15); //22SP 
- setTextSize(TypedValue.COMPLEX_UNIT_DIP,15);//22DIP

2.java The code is read dimens The value in

<dimen name="default_size">21dp</dimen> 
 Screen information ： width:480 height:800 density:1.5 densityDpi:240

getDimension(): 31.500000       ---   return float value 
getDimensionPixelSize(): 32	    ---  The actual value returned is rounded 
getDimensionPixelOffset(): 31   ---  The actual value returned is the decimal point after the result 

3. Get the width and height of the string

private int getStringHeight(String string, Paint paint) {
	Rect rect = new Rect();
	paint.getTextBounds(string, 0, string.length(), rect);
	return rect.height();
}

private int getStringWidth(String string, Paint paint) {
	Rect rect = new Rect();
	paint.getTextBounds(string, 0, string.length(), rect);
	return rect.width();
}